1 @chapter Filtering Introduction
2 @c man begin FILTERING INTRODUCTION
4 Filtering in FFmpeg is enabled through the libavfilter library.
6 Libavfilter is the filtering API of FFmpeg. It is the substitute of
7 the now deprecated 'vhooks' and started as a Google Summer of Code
10 Audio filtering integration into the main FFmpeg repository is a work in
11 progress, so audio API and ABI should not be considered stable yet.
13 In libavfilter, it is possible for filters to have multiple inputs and
15 To illustrate the sorts of things that are possible, we can
16 use a complex filter graph. For example, the following one:
19 input --> split --> fifo -----------------------> overlay --> output
22 +------> fifo --> crop --> vflip --------+
25 splits the stream in two streams, sends one stream through the crop filter
26 and the vflip filter before merging it back with the other stream by
27 overlaying it on top. You can use the following command to achieve this:
30 ffmpeg -i input -vf "[in] split [T1], fifo, [T2] overlay=0:H/2 [out]; [T1] fifo, crop=iw:ih/2:0:ih/2, vflip [T2]" output
33 The result will be that in output the top half of the video is mirrored
36 Filters are loaded using the @var{-vf} or @var{-af} option passed to
37 @command{ffmpeg} or to @command{ffplay}. Filters in the same linear
38 chain are separated by commas. In our example, @var{split, fifo,
39 overlay} are in one linear chain, and @var{fifo, crop, vflip} are in
40 another. The points where the linear chains join are labeled by names
41 enclosed in square brackets. In our example, that is @var{[T1]} and
42 @var{[T2]}. The special labels @var{[in]} and @var{[out]} are the points
43 where video is input and output.
45 Some filters take in input a list of parameters: they are specified
46 after the filter name and an equal sign, and are separated from each other
49 There exist so-called @var{source filters} that do not have an
50 audio/video input, and @var{sink filters} that will not have audio/video
53 @c man end FILTERING INTRODUCTION
56 @c man begin GRAPH2DOT
58 The @file{graph2dot} program included in the FFmpeg @file{tools}
59 directory can be used to parse a filter graph description and issue a
60 corresponding textual representation in the dot language.
67 to see how to use @file{graph2dot}.
69 You can then pass the dot description to the @file{dot} program (from
70 the graphviz suite of programs) and obtain a graphical representation
73 For example the sequence of commands:
75 echo @var{GRAPH_DESCRIPTION} | \
76 tools/graph2dot -o graph.tmp && \
77 dot -Tpng graph.tmp -o graph.png && \
81 can be used to create and display an image representing the graph
82 described by the @var{GRAPH_DESCRIPTION} string. Note that this string must be
83 a complete self-contained graph, with its inputs and outputs explicitly defined.
84 For example if your command line is of the form:
86 ffmpeg -i infile -vf scale=640:360 outfile
88 your @var{GRAPH_DESCRIPTION} string will need to be of the form:
90 nullsrc,scale=640:360,nullsink
92 you may also need to set the @var{nullsrc} parameters and add a @var{format}
93 filter in order to simulate a specific input file.
97 @chapter Filtergraph description
98 @c man begin FILTERGRAPH DESCRIPTION
100 A filtergraph is a directed graph of connected filters. It can contain
101 cycles, and there can be multiple links between a pair of
102 filters. Each link has one input pad on one side connecting it to one
103 filter from which it takes its input, and one output pad on the other
104 side connecting it to the one filter accepting its output.
106 Each filter in a filtergraph is an instance of a filter class
107 registered in the application, which defines the features and the
108 number of input and output pads of the filter.
110 A filter with no input pads is called a "source", a filter with no
111 output pads is called a "sink".
113 @anchor{Filtergraph syntax}
114 @section Filtergraph syntax
116 A filtergraph can be represented using a textual representation, which is
117 recognized by the @option{-filter}/@option{-vf} and @option{-filter_complex}
118 options in @command{ffmpeg} and @option{-vf} in @command{ffplay}, and by the
119 @code{avfilter_graph_parse()}/@code{avfilter_graph_parse2()} function defined in
120 @file{libavfilter/avfiltergraph.h}.
122 A filterchain consists of a sequence of connected filters, each one
123 connected to the previous one in the sequence. A filterchain is
124 represented by a list of ","-separated filter descriptions.
126 A filtergraph consists of a sequence of filterchains. A sequence of
127 filterchains is represented by a list of ";"-separated filterchain
130 A filter is represented by a string of the form:
131 [@var{in_link_1}]...[@var{in_link_N}]@var{filter_name}=@var{arguments}[@var{out_link_1}]...[@var{out_link_M}]
133 @var{filter_name} is the name of the filter class of which the
134 described filter is an instance of, and has to be the name of one of
135 the filter classes registered in the program.
136 The name of the filter class is optionally followed by a string
139 @var{arguments} is a string which contains the parameters used to
140 initialize the filter instance, and are described in the filter
143 The list of arguments can be quoted using the character "'" as initial
144 and ending mark, and the character '\' for escaping the characters
145 within the quoted text; otherwise the argument string is considered
146 terminated when the next special character (belonging to the set
147 "[]=;,") is encountered.
149 The name and arguments of the filter are optionally preceded and
150 followed by a list of link labels.
151 A link label allows to name a link and associate it to a filter output
152 or input pad. The preceding labels @var{in_link_1}
153 ... @var{in_link_N}, are associated to the filter input pads,
154 the following labels @var{out_link_1} ... @var{out_link_M}, are
155 associated to the output pads.
157 When two link labels with the same name are found in the
158 filtergraph, a link between the corresponding input and output pad is
161 If an output pad is not labelled, it is linked by default to the first
162 unlabelled input pad of the next filter in the filterchain.
163 For example in the filterchain:
165 nullsrc, split[L1], [L2]overlay, nullsink
167 the split filter instance has two output pads, and the overlay filter
168 instance two input pads. The first output pad of split is labelled
169 "L1", the first input pad of overlay is labelled "L2", and the second
170 output pad of split is linked to the second input pad of overlay,
171 which are both unlabelled.
173 In a complete filterchain all the unlabelled filter input and output
174 pads must be connected. A filtergraph is considered valid if all the
175 filter input and output pads of all the filterchains are connected.
177 Libavfilter will automatically insert scale filters where format
178 conversion is required. It is possible to specify swscale flags
179 for those automatically inserted scalers by prepending
180 @code{sws_flags=@var{flags};}
181 to the filtergraph description.
183 Follows a BNF description for the filtergraph syntax:
185 @var{NAME} ::= sequence of alphanumeric characters and '_'
186 @var{LINKLABEL} ::= "[" @var{NAME} "]"
187 @var{LINKLABELS} ::= @var{LINKLABEL} [@var{LINKLABELS}]
188 @var{FILTER_ARGUMENTS} ::= sequence of chars (eventually quoted)
189 @var{FILTER} ::= [@var{LINKNAMES}] @var{NAME} ["=" @var{ARGUMENTS}] [@var{LINKNAMES}]
190 @var{FILTERCHAIN} ::= @var{FILTER} [,@var{FILTERCHAIN}]
191 @var{FILTERGRAPH} ::= [sws_flags=@var{flags};] @var{FILTERCHAIN} [;@var{FILTERGRAPH}]
194 @c man end FILTERGRAPH DESCRIPTION
196 @chapter Audio Filters
197 @c man begin AUDIO FILTERS
199 When you configure your FFmpeg build, you can disable any of the
200 existing filters using @code{--disable-filters}.
201 The configure output will show the audio filters included in your
204 Below is a description of the currently available audio filters.
208 Convert the input audio format to the specified formats.
210 The filter accepts a string of the form:
211 "@var{sample_format}:@var{channel_layout}".
213 @var{sample_format} specifies the sample format, and can be a string or the
214 corresponding numeric value defined in @file{libavutil/samplefmt.h}. Use 'p'
215 suffix for a planar sample format.
217 @var{channel_layout} specifies the channel layout, and can be a string
218 or the corresponding number value defined in @file{libavutil/audioconvert.h}.
220 The special parameter "auto", signifies that the filter will
221 automatically select the output format depending on the output filter.
223 Some examples follow.
227 Convert input to float, planar, stereo:
233 Convert input to unsigned 8-bit, automatically select out channel layout:
241 Convert the input audio to one of the specified formats. The framework will
242 negotiate the most appropriate format to minimize conversions.
244 The filter accepts the following named parameters:
248 A comma-separated list of requested sample formats.
251 A comma-separated list of requested sample rates.
253 @item channel_layouts
254 A comma-separated list of requested channel layouts.
258 If a parameter is omitted, all values are allowed.
260 For example to force the output to either unsigned 8-bit or signed 16-bit stereo:
262 aformat=sample_fmts\=u8\,s16:channel_layouts\=stereo
267 Merge two or more audio streams into a single multi-channel stream.
269 The filter accepts the following named options:
274 Set the number of inputs. Default is 2.
278 If the channel layouts of the inputs are disjoint, and therefore compatible,
279 the channel layout of the output will be set accordingly and the channels
280 will be reordered as necessary. If the channel layouts of the inputs are not
281 disjoint, the output will have all the channels of the first input then all
282 the channels of the second input, in that order, and the channel layout of
283 the output will be the default value corresponding to the total number of
286 For example, if the first input is in 2.1 (FL+FR+LF) and the second input
287 is FC+BL+BR, then the output will be in 5.1, with the channels in the
288 following order: a1, a2, b1, a3, b2, b3 (a1 is the first channel of the
289 first input, b1 is the first channel of the second input).
291 On the other hand, if both input are in stereo, the output channels will be
292 in the default order: a1, a2, b1, b2, and the channel layout will be
293 arbitrarily set to 4.0, which may or may not be the expected value.
295 All inputs must have the same sample rate, and format.
297 If inputs do not have the same duration, the output will stop with the
300 Example: merge two mono files into a stereo stream:
302 amovie=left.wav [l] ; amovie=right.mp3 [r] ; [l] [r] amerge
305 Example: multiple merges:
308 amovie=input.mkv:si=0 [a0];
309 amovie=input.mkv:si=1 [a1];
310 amovie=input.mkv:si=2 [a2];
311 amovie=input.mkv:si=3 [a3];
312 amovie=input.mkv:si=4 [a4];
313 amovie=input.mkv:si=5 [a5];
314 [a0][a1][a2][a3][a4][a5] amerge=inputs=6" -c:a pcm_s16le output.mkv
319 Mixes multiple audio inputs into a single output.
323 ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex amix=inputs=3:duration=first:dropout_transition=3 OUTPUT
325 will mix 3 input audio streams to a single output with the same duration as the
326 first input and a dropout transition time of 3 seconds.
328 The filter accepts the following named parameters:
332 Number of inputs. If unspecified, it defaults to 2.
335 How to determine the end-of-stream.
339 Duration of longest input. (default)
342 Duration of shortest input.
345 Duration of first input.
349 @item dropout_transition
350 Transition time, in seconds, for volume renormalization when an input
351 stream ends. The default value is 2 seconds.
357 Pass the audio source unchanged to the output.
361 Resample the input audio to the specified sample rate.
363 The filter accepts exactly one parameter, the output sample rate. If not
364 specified then the filter will automatically convert between its input
365 and output sample rates.
367 For example, to resample the input audio to 44100Hz:
372 @section asetnsamples
374 Set the number of samples per each output audio frame.
376 The last output packet may contain a different number of samples, as
377 the filter will flush all the remaining samples when the input audio
380 The filter accepts parameters as a list of @var{key}=@var{value} pairs,
385 @item nb_out_samples, n
386 Set the number of frames per each output audio frame. The number is
387 intended as the number of samples @emph{per each channel}.
388 Default value is 1024.
391 If set to 1, the filter will pad the last audio frame with zeroes, so
392 that the last frame will contain the same number of samples as the
393 previous ones. Default value is 1.
396 For example, to set the number of per-frame samples to 1234 and
397 disable padding for the last frame, use:
399 asetnsamples=n=1234:p=0
404 Show a line containing various information for each input audio frame.
405 The input audio is not modified.
407 The shown line contains a sequence of key/value pairs of the form
408 @var{key}:@var{value}.
410 A description of each shown parameter follows:
414 sequential number of the input frame, starting from 0
417 presentation TimeStamp of the input frame, expressed as a number of
418 time base units. The time base unit depends on the filter input pad, and
419 is usually 1/@var{sample_rate}.
422 presentation TimeStamp of the input frame, expressed as a number of
426 position of the frame in the input stream, -1 if this information in
427 unavailable and/or meaningless (for example in case of synthetic audio)
433 channel layout description
436 number of samples (per each channel) contained in the filtered frame
439 sample rate for the audio frame
442 Adler-32 checksum (printed in hexadecimal) of all the planes of the input frame
445 Adler-32 checksum (printed in hexadecimal) for each input frame plane,
446 expressed in the form "[@var{c0} @var{c1} @var{c2} @var{c3} @var{c4} @var{c5}
452 Split input audio into several identical outputs.
454 The filter accepts a single parameter which specifies the number of outputs. If
455 unspecified, it defaults to 2.
459 [in] asplit [out0][out1]
462 will create two separate outputs from the same input.
464 To create 3 or more outputs, you need to specify the number of
467 [in] asplit=3 [out0][out1][out2]
471 ffmpeg -i INPUT -filter_complex asplit=5 OUTPUT
473 will create 5 copies of the input audio.
478 Forward two audio streams and control the order the buffers are forwarded.
480 The argument to the filter is an expression deciding which stream should be
481 forwarded next: if the result is negative, the first stream is forwarded; if
482 the result is positive or zero, the second stream is forwarded. It can use
483 the following variables:
487 number of buffers forwarded so far on each stream
489 number of samples forwarded so far on each stream
491 current timestamp of each stream
494 The default value is @code{t1-t2}, which means to always forward the stream
495 that has a smaller timestamp.
497 Example: stress-test @code{amerge} by randomly sending buffers on the wrong
498 input, while avoiding too much of a desynchronization:
500 amovie=file.ogg [a] ; amovie=file.mp3 [b] ;
501 [a] [b] astreamsync=(2*random(1))-1+tanh(5*(t1-t2)) [a2] [b2] ;
509 The filter accepts exactly one parameter, the audio tempo. If not
510 specified then the filter will assume nominal 1.0 tempo. Tempo must
511 be in the [0.5, 2.0] range.
513 For example, to slow down audio to 80% tempo:
518 For example, to speed up audio to 125% tempo:
525 Make audio easier to listen to on headphones.
527 This filter adds `cues' to 44.1kHz stereo (i.e. audio CD format) audio
528 so that when listened to on headphones the stereo image is moved from
529 inside your head (standard for headphones) to outside and in front of
530 the listener (standard for speakers).
536 Mix channels with specific gain levels. The filter accepts the output
537 channel layout followed by a set of channels definitions.
539 This filter is also designed to remap efficiently the channels of an audio
542 The filter accepts parameters of the form:
543 "@var{l}:@var{outdef}:@var{outdef}:..."
547 output channel layout or number of channels
550 output channel specification, of the form:
551 "@var{out_name}=[@var{gain}*]@var{in_name}[+[@var{gain}*]@var{in_name}...]"
554 output channel to define, either a channel name (FL, FR, etc.) or a channel
555 number (c0, c1, etc.)
558 multiplicative coefficient for the channel, 1 leaving the volume unchanged
561 input channel to use, see out_name for details; it is not possible to mix
562 named and numbered input channels
565 If the `=' in a channel specification is replaced by `<', then the gains for
566 that specification will be renormalized so that the total is 1, thus
567 avoiding clipping noise.
569 @subsection Mixing examples
571 For example, if you want to down-mix from stereo to mono, but with a bigger
572 factor for the left channel:
574 pan=1:c0=0.9*c0+0.1*c1
577 A customized down-mix to stereo that works automatically for 3-, 4-, 5- and
580 pan=stereo: FL < FL + 0.5*FC + 0.6*BL + 0.6*SL : FR < FR + 0.5*FC + 0.6*BR + 0.6*SR
583 Note that @command{ffmpeg} integrates a default down-mix (and up-mix) system
584 that should be preferred (see "-ac" option) unless you have very specific
587 @subsection Remapping examples
589 The channel remapping will be effective if, and only if:
592 @item gain coefficients are zeroes or ones,
593 @item only one input per channel output,
596 If all these conditions are satisfied, the filter will notify the user ("Pure
597 channel mapping detected"), and use an optimized and lossless method to do the
600 For example, if you have a 5.1 source and want a stereo audio stream by
601 dropping the extra channels:
603 pan="stereo: c0=FL : c1=FR"
606 Given the same source, you can also switch front left and front right channels
607 and keep the input channel layout:
609 pan="5.1: c0=c1 : c1=c0 : c2=c2 : c3=c3 : c4=c4 : c5=c5"
612 If the input is a stereo audio stream, you can mute the front left channel (and
613 still keep the stereo channel layout) with:
618 Still with a stereo audio stream input, you can copy the right channel in both
619 front left and right:
621 pan="stereo: c0=FR : c1=FR"
624 @section silencedetect
626 Detect silence in an audio stream.
628 This filter logs a message when it detects that the input audio volume is less
629 or equal to a noise tolerance value for a duration greater or equal to the
630 minimum detected noise duration.
632 The printed times and duration are expressed in seconds.
636 Set silence duration until notification (default is 2 seconds).
639 Set noise tolerance. Can be specified in dB (in case "dB" is appended to the
640 specified value) or amplitude ratio. Default is -60dB, or 0.001.
643 Detect 5 seconds of silence with -50dB noise tolerance:
645 silencedetect=n=-50dB:d=5
648 Complete example with @command{ffmpeg} to detect silence with 0.0001 noise
649 tolerance in @file{silence.mp3}:
651 ffmpeg -f lavfi -i amovie=silence.mp3,silencedetect=noise=0.0001 -f null -
656 Adjust the input audio volume.
658 The filter accepts exactly one parameter @var{vol}, which expresses
659 how the audio volume will be increased or decreased.
661 Output values are clipped to the maximum value.
663 If @var{vol} is expressed as a decimal number, the output audio
664 volume is given by the relation:
666 @var{output_volume} = @var{vol} * @var{input_volume}
669 If @var{vol} is expressed as a decimal number followed by the string
670 "dB", the value represents the requested change in decibels of the
671 input audio power, and the output audio volume is given by the
674 @var{output_volume} = 10^(@var{vol}/20) * @var{input_volume}
677 Otherwise @var{vol} is considered an expression and its evaluated
678 value is used for computing the output audio volume according to the
681 Default value for @var{vol} is 1.0.
687 Half the input audio volume:
692 The above example is equivalent to:
698 Decrease input audio power by 12 decibels:
704 @section volumedetect
706 Detect the volume of the input video.
708 The filter has no parameters. The input is not modified. Statistics about
709 the volume will be printed in the log when the input stream end is reached.
711 In particular it will show the mean volume (root mean square), maximum
712 volume (on a per-sample basis), and the beginning of an histogram of the
713 registered volume values (from the maximum value to a cumulated 1/1000 of
716 All volumes are in decibels relative to the maximum PCM value.
718 Here is an excerpt of the output:
720 [Parsed_volumedetect_0 @ 0xa23120] mean_volume: -27 dB
721 [Parsed_volumedetect_0 @ 0xa23120] max_volume: -4 dB
722 [Parsed_volumedetect_0 @ 0xa23120] histogram_4db: 6
723 [Parsed_volumedetect_0 @ 0xa23120] histogram_5db: 62
724 [Parsed_volumedetect_0 @ 0xa23120] histogram_6db: 286
725 [Parsed_volumedetect_0 @ 0xa23120] histogram_7db: 1042
726 [Parsed_volumedetect_0 @ 0xa23120] histogram_8db: 2551
727 [Parsed_volumedetect_0 @ 0xa23120] histogram_9db: 4609
728 [Parsed_volumedetect_0 @ 0xa23120] histogram_10db: 8409
734 The mean square energy is approximately -27 dB, or 10^-2.7.
736 The largest sample is at -4 dB, or more precisely between -4 dB and -5 dB.
738 There are 6 samples at -4 dB, 62 at -5 dB, 286 at -6 dB, etc.
741 In other words, raising the volume by +4 dB does not cause any clipping,
742 raising it by +5 dB causes clipping for 6 samples, etc.
745 Synchronize audio data with timestamps by squeezing/stretching it and/or
746 dropping samples/adding silence when needed.
748 The filter accepts the following named parameters:
752 Enable stretching/squeezing the data to make it match the timestamps. Disabled
753 by default. When disabled, time gaps are covered with silence.
756 Minimum difference between timestamps and audio data (in seconds) to trigger
757 adding/dropping samples. Default value is 0.1. If you get non-perfect sync with
758 this filter, try setting this parameter to 0.
761 Maximum compensation in samples per second. Relevant only with compensate=1.
765 Assume the first pts should be this value.
766 This allows for padding/trimming at the start of stream. By default, no
767 assumption is made about the first frame's expected pts, so no padding or
768 trimming is done. For example, this could be set to 0 to pad the beginning with
769 silence if an audio stream starts after the video stream.
773 @section channelsplit
774 Split each channel in input audio stream into a separate output stream.
776 This filter accepts the following named parameters:
779 Channel layout of the input stream. Default is "stereo".
782 For example, assuming a stereo input MP3 file
784 ffmpeg -i in.mp3 -filter_complex channelsplit out.mkv
786 will create an output Matroska file with two audio streams, one containing only
787 the left channel and the other the right channel.
789 To split a 5.1 WAV file into per-channel files
791 ffmpeg -i in.wav -filter_complex
792 'channelsplit=channel_layout=5.1[FL][FR][FC][LFE][SL][SR]'
793 -map '[FL]' front_left.wav -map '[FR]' front_right.wav -map '[FC]'
794 front_center.wav -map '[LFE]' lfe.wav -map '[SL]' side_left.wav -map '[SR]'
799 Remap input channels to new locations.
801 This filter accepts the following named parameters:
804 Channel layout of the output stream.
807 Map channels from input to output. The argument is a comma-separated list of
808 mappings, each in the @code{@var{in_channel}-@var{out_channel}} or
809 @var{in_channel} form. @var{in_channel} can be either the name of the input
810 channel (e.g. FL for front left) or its index in the input channel layout.
811 @var{out_channel} is the name of the output channel or its index in the output
812 channel layout. If @var{out_channel} is not given then it is implicitly an
813 index, starting with zero and increasing by one for each mapping.
816 If no mapping is present, the filter will implicitly map input channels to
817 output channels preserving index.
819 For example, assuming a 5.1+downmix input MOV file
821 ffmpeg -i in.mov -filter 'channelmap=map=DL-FL\,DR-FR' out.wav
823 will create an output WAV file tagged as stereo from the downmix channels of
826 To fix a 5.1 WAV improperly encoded in AAC's native channel order
828 ffmpeg -i in.wav -filter 'channelmap=1\,2\,0\,5\,3\,4:channel_layout=5.1' out.wav
832 Join multiple input streams into one multi-channel stream.
834 The filter accepts the following named parameters:
838 Number of input streams. Defaults to 2.
841 Desired output channel layout. Defaults to stereo.
844 Map channels from inputs to output. The argument is a comma-separated list of
845 mappings, each in the @code{@var{input_idx}.@var{in_channel}-@var{out_channel}}
846 form. @var{input_idx} is the 0-based index of the input stream. @var{in_channel}
847 can be either the name of the input channel (e.g. FL for front left) or its
848 index in the specified input stream. @var{out_channel} is the name of the output
852 The filter will attempt to guess the mappings when those are not specified
853 explicitly. It does so by first trying to find an unused matching input channel
854 and if that fails it picks the first unused input channel.
856 E.g. to join 3 inputs (with properly set channel layouts)
858 ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex join=inputs=3 OUTPUT
861 To build a 5.1 output from 6 single-channel streams:
863 ffmpeg -i fl -i fr -i fc -i sl -i sr -i lfe -filter_complex
864 'join=inputs=6:channel_layout=5.1:map=0.0-FL\,1.0-FR\,2.0-FC\,3.0-SL\,4.0-SR\,5.0-LFE'
869 Convert the audio sample format, sample rate and channel layout. This filter is
870 not meant to be used directly.
872 @c man end AUDIO FILTERS
874 @chapter Audio Sources
875 @c man begin AUDIO SOURCES
877 Below is a description of the currently available audio sources.
881 Buffer audio frames, and make them available to the filter chain.
883 This source is mainly intended for a programmatic use, in particular
884 through the interface defined in @file{libavfilter/asrc_abuffer.h}.
886 It accepts the following mandatory parameters:
887 @var{sample_rate}:@var{sample_fmt}:@var{channel_layout}
892 The sample rate of the incoming audio buffers.
895 The sample format of the incoming audio buffers.
896 Either a sample format name or its corresponging integer representation from
897 the enum AVSampleFormat in @file{libavutil/samplefmt.h}
900 The channel layout of the incoming audio buffers.
901 Either a channel layout name from channel_layout_map in
902 @file{libavutil/audioconvert.c} or its corresponding integer representation
903 from the AV_CH_LAYOUT_* macros in @file{libavutil/audioconvert.h}
909 abuffer=44100:s16p:stereo
912 will instruct the source to accept planar 16bit signed stereo at 44100Hz.
913 Since the sample format with name "s16p" corresponds to the number
914 6 and the "stereo" channel layout corresponds to the value 0x3, this is
922 Generate an audio signal specified by an expression.
924 This source accepts in input one or more expressions (one for each
925 channel), which are evaluated and used to generate a corresponding
928 It accepts the syntax: @var{exprs}[::@var{options}].
929 @var{exprs} is a list of expressions separated by ":", one for each
930 separate channel. In case the @var{channel_layout} is not
931 specified, the selected channel layout depends on the number of
932 provided expressions.
934 @var{options} is an optional sequence of @var{key}=@var{value} pairs,
937 The description of the accepted options follows.
941 @item channel_layout, c
942 Set the channel layout. The number of channels in the specified layout
943 must be equal to the number of specified expressions.
946 Set the minimum duration of the sourced audio. See the function
947 @code{av_parse_time()} for the accepted format.
948 Note that the resulting duration may be greater than the specified
949 duration, as the generated audio is always cut at the end of a
952 If not specified, or the expressed duration is negative, the audio is
953 supposed to be generated forever.
956 Set the number of samples per channel per each output frame,
960 Specify the sample rate, default to 44100.
963 Each expression in @var{exprs} can contain the following constants:
967 number of the evaluated sample, starting from 0
970 time of the evaluated sample expressed in seconds, starting from 0
989 Generate a sin signal with frequency of 440 Hz, set sample rate to
992 aevalsrc="sin(440*2*PI*t)::s=8000"
996 Generate a two channels signal, specify the channel layout (Front
997 Center + Back Center) explicitly:
999 aevalsrc="sin(420*2*PI*t):cos(430*2*PI*t)::c=FC|BC"
1003 Generate white noise:
1005 aevalsrc="-2+random(0)"
1009 Generate an amplitude modulated signal:
1011 aevalsrc="sin(10*2*PI*t)*sin(880*2*PI*t)"
1015 Generate 2.5 Hz binaural beats on a 360 Hz carrier:
1017 aevalsrc="0.1*sin(2*PI*(360-2.5/2)*t) : 0.1*sin(2*PI*(360+2.5/2)*t)"
1024 Null audio source, return unprocessed audio frames. It is mainly useful
1025 as a template and to be employed in analysis / debugging tools, or as
1026 the source for filters which ignore the input data (for example the sox
1029 It accepts an optional sequence of @var{key}=@var{value} pairs,
1032 The description of the accepted options follows.
1036 @item sample_rate, s
1037 Specify the sample rate, and defaults to 44100.
1039 @item channel_layout, cl
1041 Specify the channel layout, and can be either an integer or a string
1042 representing a channel layout. The default value of @var{channel_layout}
1045 Check the channel_layout_map definition in
1046 @file{libavcodec/audioconvert.c} for the mapping between strings and
1047 channel layout values.
1050 Set the number of samples per requested frames.
1054 Follow some examples:
1056 # set the sample rate to 48000 Hz and the channel layout to AV_CH_LAYOUT_MONO.
1057 anullsrc=r=48000:cl=4
1060 anullsrc=r=48000:cl=mono
1064 Buffer audio frames, and make them available to the filter chain.
1066 This source is not intended to be part of user-supplied graph descriptions but
1067 for insertion by calling programs through the interface defined in
1068 @file{libavfilter/buffersrc.h}.
1070 It accepts the following named parameters:
1074 Timebase which will be used for timestamps of submitted frames. It must be
1075 either a floating-point number or in @var{numerator}/@var{denominator} form.
1081 Name of the sample format, as returned by @code{av_get_sample_fmt_name()}.
1083 @item channel_layout
1084 Channel layout of the audio data, in the form that can be accepted by
1085 @code{av_get_channel_layout()}.
1088 All the parameters need to be explicitly defined.
1092 Synthesize a voice utterance using the libflite library.
1094 To enable compilation of this filter you need to configure FFmpeg with
1095 @code{--enable-libflite}.
1097 Note that the flite library is not thread-safe.
1099 The source accepts parameters as a list of @var{key}=@var{value} pairs,
1102 The description of the accepted parameters follows.
1107 If set to 1, list the names of the available voices and exit
1108 immediately. Default value is 0.
1111 Set the maximum number of samples per frame. Default value is 512.
1114 Set the filename containing the text to speak.
1117 Set the text to speak.
1120 Set the voice to use for the speech synthesis. Default value is
1121 @code{kal}. See also the @var{list_voices} option.
1124 @subsection Examples
1128 Read from file @file{speech.txt}, and synthetize the text using the
1129 standard flite voice:
1131 flite=textfile=speech.txt
1135 Read the specified text selecting the @code{slt} voice:
1137 flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
1141 Input text to ffmpeg:
1143 ffmpeg -f lavfi -i flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
1147 Make @file{ffplay} speech the specified text, using @code{flite} and
1148 the @code{lavfi} device:
1150 ffplay -f lavfi flite=text='No more be grieved for which that thou hast done.'
1154 For more information about libflite, check:
1155 @url{http://www.speech.cs.cmu.edu/flite/}
1157 @c man end AUDIO SOURCES
1159 @chapter Audio Sinks
1160 @c man begin AUDIO SINKS
1162 Below is a description of the currently available audio sinks.
1164 @section abuffersink
1166 Buffer audio frames, and make them available to the end of filter chain.
1168 This sink is mainly intended for programmatic use, in particular
1169 through the interface defined in @file{libavfilter/buffersink.h}.
1171 It requires a pointer to an AVABufferSinkContext structure, which
1172 defines the incoming buffers' formats, to be passed as the opaque
1173 parameter to @code{avfilter_init_filter} for initialization.
1177 Null audio sink, do absolutely nothing with the input audio. It is
1178 mainly useful as a template and to be employed in analysis / debugging
1181 @section abuffersink
1182 This sink is intended for programmatic use. Frames that arrive on this sink can
1183 be retrieved by the calling program using the interface defined in
1184 @file{libavfilter/buffersink.h}.
1186 This filter accepts no parameters.
1188 @c man end AUDIO SINKS
1190 @chapter Video Filters
1191 @c man begin VIDEO FILTERS
1193 When you configure your FFmpeg build, you can disable any of the
1194 existing filters using @code{--disable-filters}.
1195 The configure output will show the video filters included in your
1198 Below is a description of the currently available video filters.
1200 @section alphaextract
1202 Extract the alpha component from the input as a grayscale video. This
1203 is especially useful with the @var{alphamerge} filter.
1207 Add or replace the alpha component of the primary input with the
1208 grayscale value of a second input. This is intended for use with
1209 @var{alphaextract} to allow the transmission or storage of frame
1210 sequences that have alpha in a format that doesn't support an alpha
1213 For example, to reconstruct full frames from a normal YUV-encoded video
1214 and a separate video created with @var{alphaextract}, you might use:
1216 movie=in_alpha.mkv [alpha]; [in][alpha] alphamerge [out]
1219 Since this filter is designed for reconstruction, it operates on frame
1220 sequences without considering timestamps, and terminates when either
1221 input reaches end of stream. This will cause problems if your encoding
1222 pipeline drops frames. If you're trying to apply an image as an
1223 overlay to a video stream, consider the @var{overlay} filter instead.
1227 Draw ASS (Advanced Substation Alpha) subtitles on top of input video
1228 using the libass library.
1230 To enable compilation of this filter you need to configure FFmpeg with
1231 @code{--enable-libass}.
1233 This filter accepts the syntax: @var{ass_filename}[:@var{options}],
1234 where @var{ass_filename} is the filename of the ASS file to read, and
1235 @var{options} is an optional sequence of @var{key}=@var{value} pairs,
1238 A description of the accepted options follows.
1242 Specifies the size of the original video, the video for which the ASS file
1243 was composed. Due to a misdesign in ASS aspect ratio arithmetic, this is
1244 necessary to correctly scale the fonts if the aspect ratio has been changed.
1247 For example, to render the file @file{sub.ass} on top of the input
1248 video, use the command:
1255 Compute the bounding box for the non-black pixels in the input frame
1258 This filter computes the bounding box containing all the pixels with a
1259 luminance value greater than the minimum allowed value.
1260 The parameters describing the bounding box are printed on the filter
1263 @section blackdetect
1265 Detect video intervals that are (almost) completely black. Can be
1266 useful to detect chapter transitions, commercials, or invalid
1267 recordings. Output lines contains the time for the start, end and
1268 duration of the detected black interval expressed in seconds.
1270 In order to display the output lines, you need to set the loglevel at
1271 least to the AV_LOG_INFO value.
1273 This filter accepts a list of options in the form of
1274 @var{key}=@var{value} pairs separated by ":". A description of the
1275 accepted options follows.
1278 @item black_min_duration, d
1279 Set the minimum detected black duration expressed in seconds. It must
1280 be a non-negative floating point number.
1282 Default value is 2.0.
1284 @item picture_black_ratio_th, pic_th
1285 Set the threshold for considering a picture "black".
1286 Express the minimum value for the ratio:
1288 @var{nb_black_pixels} / @var{nb_pixels}
1291 for which a picture is considered black.
1292 Default value is 0.98.
1294 @item pixel_black_th, pix_th
1295 Set the threshold for considering a pixel "black".
1297 The threshold expresses the maximum pixel luminance value for which a
1298 pixel is considered "black". The provided value is scaled according to
1299 the following equation:
1301 @var{absolute_threshold} = @var{luminance_minimum_value} + @var{pixel_black_th} * @var{luminance_range_size}
1304 @var{luminance_range_size} and @var{luminance_minimum_value} depend on
1305 the input video format, the range is [0-255] for YUV full-range
1306 formats and [16-235] for YUV non full-range formats.
1308 Default value is 0.10.
1311 The following example sets the maximum pixel threshold to the minimum
1312 value, and detects only black intervals of 2 or more seconds:
1314 blackdetect=d=2:pix_th=0.00
1319 Detect frames that are (almost) completely black. Can be useful to
1320 detect chapter transitions or commercials. Output lines consist of
1321 the frame number of the detected frame, the percentage of blackness,
1322 the position in the file if known or -1 and the timestamp in seconds.
1324 In order to display the output lines, you need to set the loglevel at
1325 least to the AV_LOG_INFO value.
1327 The filter accepts the syntax:
1329 blackframe[=@var{amount}:[@var{threshold}]]
1332 @var{amount} is the percentage of the pixels that have to be below the
1333 threshold, and defaults to 98.
1335 @var{threshold} is the threshold below which a pixel value is
1336 considered black, and defaults to 32.
1340 Apply boxblur algorithm to the input video.
1342 This filter accepts the parameters:
1343 @var{luma_radius}:@var{luma_power}:@var{chroma_radius}:@var{chroma_power}:@var{alpha_radius}:@var{alpha_power}
1345 Chroma and alpha parameters are optional, if not specified they default
1346 to the corresponding values set for @var{luma_radius} and
1349 @var{luma_radius}, @var{chroma_radius}, and @var{alpha_radius} represent
1350 the radius in pixels of the box used for blurring the corresponding
1351 input plane. They are expressions, and can contain the following
1355 the input width and height in pixels
1358 the input chroma image width and height in pixels
1361 horizontal and vertical chroma subsample values. For example for the
1362 pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
1365 The radius must be a non-negative number, and must not be greater than
1366 the value of the expression @code{min(w,h)/2} for the luma and alpha planes,
1367 and of @code{min(cw,ch)/2} for the chroma planes.
1369 @var{luma_power}, @var{chroma_power}, and @var{alpha_power} represent
1370 how many times the boxblur filter is applied to the corresponding
1373 Some examples follow:
1378 Apply a boxblur filter with luma, chroma, and alpha radius
1385 Set luma radius to 2, alpha and chroma radius to 0
1391 Set luma and chroma radius to a fraction of the video dimension
1393 boxblur=min(h\,w)/10:1:min(cw\,ch)/10:1
1398 @section colormatrix
1400 The colormatrix filter allows conversion between any of the following color
1401 space: BT.709 (@var{bt709}), BT.601 (@var{bt601}), SMPTE-240M (@var{smpte240m})
1402 and FCC (@var{fcc}).
1404 The syntax of the parameters is @var{source}:@var{destination}:
1407 colormatrix=bt601:smpte240m
1412 Copy the input source unchanged to the output. Mainly useful for
1417 Crop the input video to @var{out_w}:@var{out_h}:@var{x}:@var{y}:@var{keep_aspect}
1419 The @var{keep_aspect} parameter is optional, if specified and set to a
1420 non-zero value will force the output display aspect ratio to be the
1421 same of the input, by changing the output sample aspect ratio.
1423 The @var{out_w}, @var{out_h}, @var{x}, @var{y} parameters are
1424 expressions containing the following constants:
1428 the computed values for @var{x} and @var{y}. They are evaluated for
1432 the input width and height
1435 same as @var{in_w} and @var{in_h}
1438 the output (cropped) width and height
1441 same as @var{out_w} and @var{out_h}
1444 same as @var{iw} / @var{ih}
1447 input sample aspect ratio
1450 input display aspect ratio, it is the same as (@var{iw} / @var{ih}) * @var{sar}
1453 horizontal and vertical chroma subsample values. For example for the
1454 pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
1457 the number of input frame, starting from 0
1460 the position in the file of the input frame, NAN if unknown
1463 timestamp expressed in seconds, NAN if the input timestamp is unknown
1467 The @var{out_w} and @var{out_h} parameters specify the expressions for
1468 the width and height of the output (cropped) video. They are
1469 evaluated just at the configuration of the filter.
1471 The default value of @var{out_w} is "in_w", and the default value of
1472 @var{out_h} is "in_h".
1474 The expression for @var{out_w} may depend on the value of @var{out_h},
1475 and the expression for @var{out_h} may depend on @var{out_w}, but they
1476 cannot depend on @var{x} and @var{y}, as @var{x} and @var{y} are
1477 evaluated after @var{out_w} and @var{out_h}.
1479 The @var{x} and @var{y} parameters specify the expressions for the
1480 position of the top-left corner of the output (non-cropped) area. They
1481 are evaluated for each frame. If the evaluated value is not valid, it
1482 is approximated to the nearest valid value.
1484 The default value of @var{x} is "(in_w-out_w)/2", and the default
1485 value for @var{y} is "(in_h-out_h)/2", which set the cropped area at
1486 the center of the input image.
1488 The expression for @var{x} may depend on @var{y}, and the expression
1489 for @var{y} may depend on @var{x}.
1491 Follow some examples:
1493 # crop the central input area with size 100x100
1496 # crop the central input area with size 2/3 of the input video
1497 "crop=2/3*in_w:2/3*in_h"
1499 # crop the input video central square
1502 # delimit the rectangle with the top-left corner placed at position
1503 # 100:100 and the right-bottom corner corresponding to the right-bottom
1504 # corner of the input image.
1505 crop=in_w-100:in_h-100:100:100
1507 # crop 10 pixels from the left and right borders, and 20 pixels from
1508 # the top and bottom borders
1509 "crop=in_w-2*10:in_h-2*20"
1511 # keep only the bottom right quarter of the input image
1512 "crop=in_w/2:in_h/2:in_w/2:in_h/2"
1514 # crop height for getting Greek harmony
1515 "crop=in_w:1/PHI*in_w"
1518 "crop=in_w/2:in_h/2:(in_w-out_w)/2+((in_w-out_w)/2)*sin(n/10):(in_h-out_h)/2 +((in_h-out_h)/2)*sin(n/7)"
1520 # erratic camera effect depending on timestamp
1521 "crop=in_w/2:in_h/2:(in_w-out_w)/2+((in_w-out_w)/2)*sin(t*10):(in_h-out_h)/2 +((in_h-out_h)/2)*sin(t*13)"
1523 # set x depending on the value of y
1524 "crop=in_w/2:in_h/2:y:10+10*sin(n/10)"
1529 Auto-detect crop size.
1531 Calculate necessary cropping parameters and prints the recommended
1532 parameters through the logging system. The detected dimensions
1533 correspond to the non-black area of the input video.
1535 It accepts the syntax:
1537 cropdetect[=@var{limit}[:@var{round}[:@var{reset}]]]
1543 Threshold, which can be optionally specified from nothing (0) to
1544 everything (255), defaults to 24.
1547 Value which the width/height should be divisible by, defaults to
1548 16. The offset is automatically adjusted to center the video. Use 2 to
1549 get only even dimensions (needed for 4:2:2 video). 16 is best when
1550 encoding to most video codecs.
1553 Counter that determines after how many frames cropdetect will reset
1554 the previously detected largest video area and start over to detect
1555 the current optimal crop area. Defaults to 0.
1557 This can be useful when channel logos distort the video area. 0
1558 indicates never reset and return the largest area encountered during
1564 This filter drops frames that do not differ greatly from the previous
1565 frame in order to reduce framerate. The main use of this filter is
1566 for very-low-bitrate encoding (e.g. streaming over dialup modem), but
1567 it could in theory be used for fixing movies that were
1568 inverse-telecined incorrectly.
1570 It accepts the following parameters:
1571 @var{max}:@var{hi}:@var{lo}:@var{frac}.
1576 Set the maximum number of consecutive frames which can be dropped (if
1577 positive), or the minimum interval between dropped frames (if
1578 negative). If the value is 0, the frame is dropped unregarding the
1579 number of previous sequentially dropped frames.
1584 Set the dropping threshold values.
1586 Values for @var{hi} and @var{lo} are for 8x8 pixel blocks and
1587 represent actual pixel value differences, so a threshold of 64
1588 corresponds to 1 unit of difference for each pixel, or the same spread
1589 out differently over the block.
1591 A frame is a candidate for dropping if no 8x8 blocks differ by more
1592 than a threshold of @var{hi}, and if no more than @var{frac} blocks (1
1593 meaning the whole image) differ by more than a threshold of @var{lo}.
1595 Default value for @var{hi} is 64*12, default value for @var{lo} is
1596 64*5, and default value for @var{frac} is 0.33.
1601 Suppress a TV station logo by a simple interpolation of the surrounding
1602 pixels. Just set a rectangle covering the logo and watch it disappear
1603 (and sometimes something even uglier appear - your mileage may vary).
1605 The filter accepts parameters as a string of the form
1606 "@var{x}:@var{y}:@var{w}:@var{h}:@var{band}", or as a list of
1607 @var{key}=@var{value} pairs, separated by ":".
1609 The description of the accepted parameters follows.
1614 Specify the top left corner coordinates of the logo. They must be
1618 Specify the width and height of the logo to clear. They must be
1622 Specify the thickness of the fuzzy edge of the rectangle (added to
1623 @var{w} and @var{h}). The default value is 4.
1626 When set to 1, a green rectangle is drawn on the screen to simplify
1627 finding the right @var{x}, @var{y}, @var{w}, @var{h} parameters, and
1628 @var{band} is set to 4. The default value is 0.
1632 Some examples follow.
1637 Set a rectangle covering the area with top left corner coordinates 0,0
1638 and size 100x77, setting a band of size 10:
1640 delogo=0:0:100:77:10
1644 As the previous example, but use named options:
1646 delogo=x=0:y=0:w=100:h=77:band=10
1653 Attempt to fix small changes in horizontal and/or vertical shift. This
1654 filter helps remove camera shake from hand-holding a camera, bumping a
1655 tripod, moving on a vehicle, etc.
1657 The filter accepts parameters as a string of the form
1658 "@var{x}:@var{y}:@var{w}:@var{h}:@var{rx}:@var{ry}:@var{edge}:@var{blocksize}:@var{contrast}:@var{search}:@var{filename}"
1660 A description of the accepted parameters follows.
1665 Specify a rectangular area where to limit the search for motion
1667 If desired the search for motion vectors can be limited to a
1668 rectangular area of the frame defined by its top left corner, width
1669 and height. These parameters have the same meaning as the drawbox
1670 filter which can be used to visualise the position of the bounding
1673 This is useful when simultaneous movement of subjects within the frame
1674 might be confused for camera motion by the motion vector search.
1676 If any or all of @var{x}, @var{y}, @var{w} and @var{h} are set to -1
1677 then the full frame is used. This allows later options to be set
1678 without specifying the bounding box for the motion vector search.
1680 Default - search the whole frame.
1683 Specify the maximum extent of movement in x and y directions in the
1684 range 0-64 pixels. Default 16.
1687 Specify how to generate pixels to fill blanks at the edge of the
1688 frame. An integer from 0 to 3 as follows:
1691 Fill zeroes at blank locations
1693 Original image at blank locations
1695 Extruded edge value at blank locations
1697 Mirrored edge at blank locations
1700 The default setting is mirror edge at blank locations.
1703 Specify the blocksize to use for motion search. Range 4-128 pixels,
1707 Specify the contrast threshold for blocks. Only blocks with more than
1708 the specified contrast (difference between darkest and lightest
1709 pixels) will be considered. Range 1-255, default 125.
1712 Specify the search strategy 0 = exhaustive search, 1 = less exhaustive
1713 search. Default - exhaustive search.
1716 If set then a detailed log of the motion search is written to the
1723 Draw a colored box on the input image.
1725 It accepts the syntax:
1727 drawbox=@var{x}:@var{y}:@var{width}:@var{height}:@var{color}
1733 Specify the top left corner coordinates of the box. Default to 0.
1736 Specify the width and height of the box, if 0 they are interpreted as
1737 the input width and height. Default to 0.
1740 Specify the color of the box to write, it can be the name of a color
1741 (case insensitive match) or a 0xRRGGBB[AA] sequence.
1744 Follow some examples:
1746 # draw a black box around the edge of the input image
1749 # draw a box with color red and an opacity of 50%
1750 drawbox=10:20:200:60:red@@0.5"
1755 Draw text string or text from specified file on top of video using the
1756 libfreetype library.
1758 To enable compilation of this filter you need to configure FFmpeg with
1759 @code{--enable-libfreetype}.
1761 The filter also recognizes strftime() sequences in the provided text
1762 and expands them accordingly. Check the documentation of strftime().
1764 The filter accepts parameters as a list of @var{key}=@var{value} pairs,
1767 The description of the accepted parameters follows.
1772 Used to draw a box around text using background color.
1773 Value should be either 1 (enable) or 0 (disable).
1774 The default value of @var{box} is 0.
1777 The color to be used for drawing box around text.
1778 Either a string (e.g. "yellow") or in 0xRRGGBB[AA] format
1779 (e.g. "0xff00ff"), possibly followed by an alpha specifier.
1780 The default value of @var{boxcolor} is "white".
1783 Set an expression which specifies if the text should be drawn. If the
1784 expression evaluates to 0, the text is not drawn. This is useful for
1785 specifying that the text should be drawn only when specific conditions
1788 Default value is "1".
1790 See below for the list of accepted constants and functions.
1793 If true, check and fix text coords to avoid clipping.
1796 The color to be used for drawing fonts.
1797 Either a string (e.g. "red") or in 0xRRGGBB[AA] format
1798 (e.g. "0xff000033"), possibly followed by an alpha specifier.
1799 The default value of @var{fontcolor} is "black".
1802 The font file to be used for drawing text. Path must be included.
1803 This parameter is mandatory.
1806 The font size to be used for drawing text.
1807 The default value of @var{fontsize} is 16.
1810 Flags to be used for loading the fonts.
1812 The flags map the corresponding flags supported by libfreetype, and are
1813 a combination of the following values:
1820 @item vertical_layout
1821 @item force_autohint
1824 @item ignore_global_advance_width
1826 @item ignore_transform
1833 Default value is "render".
1835 For more information consult the documentation for the FT_LOAD_*
1839 The color to be used for drawing a shadow behind the drawn text. It
1840 can be a color name (e.g. "yellow") or a string in the 0xRRGGBB[AA]
1841 form (e.g. "0xff00ff"), possibly followed by an alpha specifier.
1842 The default value of @var{shadowcolor} is "black".
1844 @item shadowx, shadowy
1845 The x and y offsets for the text shadow position with respect to the
1846 position of the text. They can be either positive or negative
1847 values. Default value for both is "0".
1850 The size in number of spaces to use for rendering the tab.
1854 Set the initial timecode representation in "hh:mm:ss[:;.]ff"
1855 format. It can be used with or without text parameter. @var{timecode_rate}
1856 option must be specified.
1858 @item timecode_rate, rate, r
1859 Set the timecode frame rate (timecode only).
1862 The text string to be drawn. The text must be a sequence of UTF-8
1864 This parameter is mandatory if no file is specified with the parameter
1868 A text file containing text to be drawn. The text must be a sequence
1869 of UTF-8 encoded characters.
1871 This parameter is mandatory if no text string is specified with the
1872 parameter @var{text}.
1874 If both @var{text} and @var{textfile} are specified, an error is thrown.
1877 The expressions which specify the offsets where text will be drawn
1878 within the video frame. They are relative to the top/left border of the
1881 The default value of @var{x} and @var{y} is "0".
1883 See below for the list of accepted constants and functions.
1886 The parameters for @var{x} and @var{y} are expressions containing the
1887 following constants and functions:
1891 input display aspect ratio, it is the same as (@var{w} / @var{h}) * @var{sar}
1894 horizontal and vertical chroma subsample values. For example for the
1895 pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
1898 the height of each text line
1906 @item max_glyph_a, ascent
1907 the maximum distance from the baseline to the highest/upper grid
1908 coordinate used to place a glyph outline point, for all the rendered
1910 It is a positive value, due to the grid's orientation with the Y axis
1913 @item max_glyph_d, descent
1914 the maximum distance from the baseline to the lowest grid coordinate
1915 used to place a glyph outline point, for all the rendered glyphs.
1916 This is a negative value, due to the grid's orientation, with the Y axis
1920 maximum glyph height, that is the maximum height for all the glyphs
1921 contained in the rendered text, it is equivalent to @var{ascent} -
1925 maximum glyph width, that is the maximum width for all the glyphs
1926 contained in the rendered text
1929 the number of input frame, starting from 0
1931 @item rand(min, max)
1932 return a random number included between @var{min} and @var{max}
1935 input sample aspect ratio
1938 timestamp expressed in seconds, NAN if the input timestamp is unknown
1941 the height of the rendered text
1944 the width of the rendered text
1947 the x and y offset coordinates where the text is drawn.
1949 These parameters allow the @var{x} and @var{y} expressions to refer
1950 each other, so you can for example specify @code{y=x/dar}.
1953 If libavfilter was built with @code{--enable-fontconfig}, then
1954 @option{fontfile} can be a fontconfig pattern or omitted.
1956 Some examples follow.
1961 Draw "Test Text" with font FreeSerif, using the default values for the
1962 optional parameters.
1965 drawtext="fontfile=/usr/share/fonts/truetype/freefont/FreeSerif.ttf: text='Test Text'"
1969 Draw 'Test Text' with font FreeSerif of size 24 at position x=100
1970 and y=50 (counting from the top-left corner of the screen), text is
1971 yellow with a red box around it. Both the text and the box have an
1975 drawtext="fontfile=/usr/share/fonts/truetype/freefont/FreeSerif.ttf: text='Test Text':\
1976 x=100: y=50: fontsize=24: fontcolor=yellow@@0.2: box=1: boxcolor=red@@0.2"
1979 Note that the double quotes are not necessary if spaces are not used
1980 within the parameter list.
1983 Show the text at the center of the video frame:
1985 drawtext="fontsize=30:fontfile=FreeSerif.ttf:text='hello world':x=(w-text_w)/2:y=(h-text_h-line_h)/2"
1989 Show a text line sliding from right to left in the last row of the video
1990 frame. The file @file{LONG_LINE} is assumed to contain a single line
1993 drawtext="fontsize=15:fontfile=FreeSerif.ttf:text=LONG_LINE:y=h-line_h:x=-50*t"
1997 Show the content of file @file{CREDITS} off the bottom of the frame and scroll up.
1999 drawtext="fontsize=20:fontfile=FreeSerif.ttf:textfile=CREDITS:y=h-20*t"
2003 Draw a single green letter "g", at the center of the input video.
2004 The glyph baseline is placed at half screen height.
2006 drawtext="fontsize=60:fontfile=FreeSerif.ttf:fontcolor=green:text=g:x=(w-max_glyph_w)/2:y=h/2-ascent"
2010 Show text for 1 second every 3 seconds:
2012 drawtext="fontfile=FreeSerif.ttf:fontcolor=white:x=100:y=x/dar:draw=lt(mod(t\\,3)\\,1):text='blink'"
2016 Use fontconfig to set the font. Note that the colons need to be escaped.
2018 drawtext='fontfile=Linux Libertine O-40\\:style=Semibold:text=FFmpeg'
2023 For more information about libfreetype, check:
2024 @url{http://www.freetype.org/}.
2026 For more information about fontconfig, check:
2027 @url{http://freedesktop.org/software/fontconfig/fontconfig-user.html}.
2031 Detect and draw edges. The filter uses the Canny Edge Detection algorithm.
2033 This filter accepts the following optional named parameters:
2037 Set low and high threshold values used by the Canny thresholding
2040 The high threshold selects the "strong" edge pixels, which are then
2041 connected through 8-connectivity with the "weak" edge pixels selected
2042 by the low threshold.
2044 @var{low} and @var{high} threshold values must be choosen in the range
2045 [0,1], and @var{low} should be lesser or equal to @var{high}.
2047 Default value for @var{low} is @code{20/255}, and default value for @var{high}
2053 edgedetect=low=0.1:high=0.4
2058 Apply fade-in/out effect to input video.
2060 It accepts the parameters:
2061 @var{type}:@var{start_frame}:@var{nb_frames}[:@var{options}]
2063 @var{type} specifies if the effect type, can be either "in" for
2064 fade-in, or "out" for a fade-out effect.
2066 @var{start_frame} specifies the number of the start frame for starting
2067 to apply the fade effect.
2069 @var{nb_frames} specifies the number of frames for which the fade
2070 effect has to last. At the end of the fade-in effect the output video
2071 will have the same intensity as the input video, at the end of the
2072 fade-out transition the output video will be completely black.
2074 @var{options} is an optional sequence of @var{key}=@var{value} pairs,
2075 separated by ":". The description of the accepted options follows.
2082 @item start_frame, s
2083 See @var{start_frame}.
2086 See @var{nb_frames}.
2089 If set to 1, fade only alpha channel, if one exists on the input.
2093 A few usage examples follow, usable too as test scenarios.
2095 # fade in first 30 frames of video
2098 # fade out last 45 frames of a 200-frame video
2101 # fade in first 25 frames and fade out last 25 frames of a 1000-frame video
2102 fade=in:0:25, fade=out:975:25
2104 # make first 5 frames black, then fade in from frame 5-24
2107 # fade in alpha over first 25 frames of video
2108 fade=in:0:25:alpha=1
2113 Transform the field order of the input video.
2115 It accepts one parameter which specifies the required field order that
2116 the input interlaced video will be transformed to. The parameter can
2117 assume one of the following values:
2121 output bottom field first
2123 output top field first
2126 Default value is "tff".
2128 Transformation is achieved by shifting the picture content up or down
2129 by one line, and filling the remaining line with appropriate picture content.
2130 This method is consistent with most broadcast field order converters.
2132 If the input video is not flagged as being interlaced, or it is already
2133 flagged as being of the required output field order then this filter does
2134 not alter the incoming video.
2136 This filter is very useful when converting to or from PAL DV material,
2137 which is bottom field first.
2141 ffmpeg -i in.vob -vf "fieldorder=bff" out.dv
2146 Buffer input images and send them when they are requested.
2148 This filter is mainly useful when auto-inserted by the libavfilter
2151 The filter does not take parameters.
2155 Convert the input video to one of the specified pixel formats.
2156 Libavfilter will try to pick one that is supported for the input to
2159 The filter accepts a list of pixel format names, separated by ":",
2160 for example "yuv420p:monow:rgb24".
2162 Some examples follow:
2164 # convert the input video to the format "yuv420p"
2167 # convert the input video to any of the formats in the list
2168 format=yuv420p:yuv444p:yuv410p
2173 Convert the video to specified constant framerate by duplicating or dropping
2174 frames as necessary.
2176 This filter accepts the following named parameters:
2180 Desired output framerate.
2186 Select one frame every N.
2188 This filter accepts in input a string representing a positive
2189 integer. Default argument is @code{1}.
2194 Apply a frei0r effect to the input video.
2196 To enable compilation of this filter you need to install the frei0r
2197 header and configure FFmpeg with @code{--enable-frei0r}.
2199 The filter supports the syntax:
2201 @var{filter_name}[@{:|=@}@var{param1}:@var{param2}:...:@var{paramN}]
2204 @var{filter_name} is the name to the frei0r effect to load. If the
2205 environment variable @env{FREI0R_PATH} is defined, the frei0r effect
2206 is searched in each one of the directories specified by the colon
2207 separated list in @env{FREIOR_PATH}, otherwise in the standard frei0r
2208 paths, which are in this order: @file{HOME/.frei0r-1/lib/},
2209 @file{/usr/local/lib/frei0r-1/}, @file{/usr/lib/frei0r-1/}.
2211 @var{param1}, @var{param2}, ... , @var{paramN} specify the parameters
2212 for the frei0r effect.
2214 A frei0r effect parameter can be a boolean (whose values are specified
2215 with "y" and "n"), a double, a color (specified by the syntax
2216 @var{R}/@var{G}/@var{B}, @var{R}, @var{G}, and @var{B} being float
2217 numbers from 0.0 to 1.0) or by an @code{av_parse_color()} color
2218 description), a position (specified by the syntax @var{X}/@var{Y},
2219 @var{X} and @var{Y} being float numbers) and a string.
2221 The number and kind of parameters depend on the loaded effect. If an
2222 effect parameter is not specified the default value is set.
2224 Some examples follow:
2228 Apply the distort0r effect, set the first two double parameters:
2230 frei0r=distort0r:0.5:0.01
2234 Apply the colordistance effect, takes a color as first parameter:
2236 frei0r=colordistance:0.2/0.3/0.4
2237 frei0r=colordistance:violet
2238 frei0r=colordistance:0x112233
2242 Apply the perspective effect, specify the top left and top right image
2245 frei0r=perspective:0.2/0.2:0.8/0.2
2249 For more information see:
2250 @url{http://frei0r.dyne.org}
2254 Fix the banding artifacts that are sometimes introduced into nearly flat
2255 regions by truncation to 8bit color depth.
2256 Interpolate the gradients that should go where the bands are, and
2259 This filter is designed for playback only. Do not use it prior to
2260 lossy compression, because compression tends to lose the dither and
2261 bring back the bands.
2263 The filter takes two optional parameters, separated by ':':
2264 @var{strength}:@var{radius}
2266 @var{strength} is the maximum amount by which the filter will change
2267 any one pixel. Also the threshold for detecting nearly flat
2268 regions. Acceptable values range from .51 to 255, default value is
2269 1.2, out-of-range values will be clipped to the valid range.
2271 @var{radius} is the neighborhood to fit the gradient to. A larger
2272 radius makes for smoother gradients, but also prevents the filter from
2273 modifying the pixels near detailed regions. Acceptable values are
2274 8-32, default value is 16, out-of-range values will be clipped to the
2278 # default parameters
2287 Flip the input video horizontally.
2289 For example to horizontally flip the input video with @command{ffmpeg}:
2291 ffmpeg -i in.avi -vf "hflip" out.avi
2296 High precision/quality 3d denoise filter. This filter aims to reduce
2297 image noise producing smooth images and making still images really
2298 still. It should enhance compressibility.
2300 It accepts the following optional parameters:
2301 @var{luma_spatial}:@var{chroma_spatial}:@var{luma_tmp}:@var{chroma_tmp}
2305 a non-negative float number which specifies spatial luma strength,
2308 @item chroma_spatial
2309 a non-negative float number which specifies spatial chroma strength,
2310 defaults to 3.0*@var{luma_spatial}/4.0
2313 a float number which specifies luma temporal strength, defaults to
2314 6.0*@var{luma_spatial}/4.0
2317 a float number which specifies chroma temporal strength, defaults to
2318 @var{luma_tmp}*@var{chroma_spatial}/@var{luma_spatial}
2323 Modify the hue and/or the saturation of the input.
2325 This filter accepts the following optional named options:
2329 Specify the hue angle as a number of degrees. It accepts a float
2330 number or an expression, and defaults to 0.0.
2333 Specify the hue angle as a number of degrees. It accepts a float
2334 number or an expression, and defaults to 0.0.
2337 Specify the saturation in the [-10,10] range. It accepts a float number and
2341 The @var{h}, @var{H} and @var{s} parameters are expressions containing the
2342 following constants:
2346 frame count of the input frame starting from 0
2349 presentation timestamp of the input frame expressed in time base units
2352 frame rate of the input video, NAN if the input frame rate is unknown
2355 timestamp expressed in seconds, NAN if the input timestamp is unknown
2358 time base of the input video
2361 The options can also be set using the syntax: @var{hue}:@var{saturation}
2363 In this case @var{hue} is expressed in degrees.
2365 Some examples follow:
2368 Set the hue to 90 degrees and the saturation to 1.0:
2374 Same command but expressing the hue in radians:
2380 Same command without named options, hue must be expressed in degrees:
2386 Note that "h:s" syntax does not support expressions for the values of
2387 h and s, so the following example will issue an error:
2393 Rotate hue and make the saturation swing between 0
2394 and 2 over a period of 1 second:
2396 hue="H=2*PI*t: s=sin(2*PI*t)+1"
2400 Apply a 3 seconds saturation fade-in effect starting at 0:
2405 The general fade-in expression can be written as:
2407 hue="s=min(0\, max((t-START)/DURATION\, 1))"
2411 Apply a 3 seconds saturation fade-out effect starting at 5 seconds:
2413 hue="s=max(0\, min(1\, (8-t)/3))"
2416 The general fade-out expression can be written as:
2418 hue="s=max(0\, min(1\, (START+DURATION-t)/DURATION))"
2423 @subsection Commands
2425 This filter supports the following command:
2428 Modify the hue and/or the saturation of the input video.
2429 The command accepts the same named options and syntax than when calling the
2430 filter from the command-line.
2432 If a parameter is omitted, it is kept at its current value.
2437 Interlaceing detect filter. This filter tries to detect if the input is
2438 interlaced or progressive. Top or bottom field first.
2440 @section lut, lutrgb, lutyuv
2442 Compute a look-up table for binding each pixel component input value
2443 to an output value, and apply it to input video.
2445 @var{lutyuv} applies a lookup table to a YUV input video, @var{lutrgb}
2446 to an RGB input video.
2448 These filters accept in input a ":"-separated list of options, which
2449 specify the expressions used for computing the lookup table for the
2450 corresponding pixel component values.
2452 The @var{lut} filter requires either YUV or RGB pixel formats in
2453 input, and accepts the options:
2455 @item @var{c0} (first pixel component)
2456 @item @var{c1} (second pixel component)
2457 @item @var{c2} (third pixel component)
2458 @item @var{c3} (fourth pixel component, corresponds to the alpha component)
2461 The exact component associated to each option depends on the format in
2464 The @var{lutrgb} filter requires RGB pixel formats in input, and
2465 accepts the options:
2467 @item @var{r} (red component)
2468 @item @var{g} (green component)
2469 @item @var{b} (blue component)
2470 @item @var{a} (alpha component)
2473 The @var{lutyuv} filter requires YUV pixel formats in input, and
2474 accepts the options:
2476 @item @var{y} (Y/luminance component)
2477 @item @var{u} (U/Cb component)
2478 @item @var{v} (V/Cr component)
2479 @item @var{a} (alpha component)
2482 The expressions can contain the following constants and functions:
2486 the input width and height
2489 input value for the pixel component
2492 the input value clipped in the @var{minval}-@var{maxval} range
2495 maximum value for the pixel component
2498 minimum value for the pixel component
2501 the negated value for the pixel component value clipped in the
2502 @var{minval}-@var{maxval} range , it corresponds to the expression
2503 "maxval-clipval+minval"
2506 the computed value in @var{val} clipped in the
2507 @var{minval}-@var{maxval} range
2509 @item gammaval(gamma)
2510 the computed gamma correction value of the pixel component value
2511 clipped in the @var{minval}-@var{maxval} range, corresponds to the
2513 "pow((clipval-minval)/(maxval-minval)\,@var{gamma})*(maxval-minval)+minval"
2517 All expressions default to "val".
2519 Some examples follow:
2521 # negate input video
2522 lutrgb="r=maxval+minval-val:g=maxval+minval-val:b=maxval+minval-val"
2523 lutyuv="y=maxval+minval-val:u=maxval+minval-val:v=maxval+minval-val"
2525 # the above is the same as
2526 lutrgb="r=negval:g=negval:b=negval"
2527 lutyuv="y=negval:u=negval:v=negval"
2532 # remove chroma components, turns the video into a graytone image
2533 lutyuv="u=128:v=128"
2535 # apply a luma burning effect
2538 # remove green and blue components
2541 # set a constant alpha channel value on input
2542 format=rgba,lutrgb=a="maxval-minval/2"
2544 # correct luminance gamma by a 0.5 factor
2545 lutyuv=y=gammaval(0.5)
2550 Apply an MPlayer filter to the input video.
2552 This filter provides a wrapper around most of the filters of
2555 This wrapper is considered experimental. Some of the wrapped filters
2556 may not work properly and we may drop support for them, as they will
2557 be implemented natively into FFmpeg. Thus you should avoid
2558 depending on them when writing portable scripts.
2560 The filters accepts the parameters:
2561 @var{filter_name}[:=]@var{filter_params}
2563 @var{filter_name} is the name of a supported MPlayer filter,
2564 @var{filter_params} is a string containing the parameters accepted by
2567 The list of the currently supported filters follows:
2611 The parameter syntax and behavior for the listed filters are the same
2612 of the corresponding MPlayer filters. For detailed instructions check
2613 the "VIDEO FILTERS" section in the MPlayer manual.
2615 Some examples follow:
2618 Adjust gamma, brightness, contrast:
2624 Add temporal noise to input video:
2630 See also mplayer(1), @url{http://www.mplayerhq.hu/}.
2636 This filter accepts an integer in input, if non-zero it negates the
2637 alpha component (if available). The default value in input is 0.
2641 Force libavfilter not to use any of the specified pixel formats for the
2642 input to the next filter.
2644 The filter accepts a list of pixel format names, separated by ":",
2645 for example "yuv420p:monow:rgb24".
2647 Some examples follow:
2649 # force libavfilter to use a format different from "yuv420p" for the
2650 # input to the vflip filter
2651 noformat=yuv420p,vflip
2653 # convert the input video to any of the formats not contained in the list
2654 noformat=yuv420p:yuv444p:yuv410p
2659 Pass the video source unchanged to the output.
2663 Apply video transform using libopencv.
2665 To enable this filter install libopencv library and headers and
2666 configure FFmpeg with @code{--enable-libopencv}.
2668 The filter takes the parameters: @var{filter_name}@{:=@}@var{filter_params}.
2670 @var{filter_name} is the name of the libopencv filter to apply.
2672 @var{filter_params} specifies the parameters to pass to the libopencv
2673 filter. If not specified the default values are assumed.
2675 Refer to the official libopencv documentation for more precise
2677 @url{http://opencv.willowgarage.com/documentation/c/image_filtering.html}
2679 Follows the list of supported libopencv filters.
2684 Dilate an image by using a specific structuring element.
2685 This filter corresponds to the libopencv function @code{cvDilate}.
2687 It accepts the parameters: @var{struct_el}:@var{nb_iterations}.
2689 @var{struct_el} represents a structuring element, and has the syntax:
2690 @var{cols}x@var{rows}+@var{anchor_x}x@var{anchor_y}/@var{shape}
2692 @var{cols} and @var{rows} represent the number of columns and rows of
2693 the structuring element, @var{anchor_x} and @var{anchor_y} the anchor
2694 point, and @var{shape} the shape for the structuring element, and
2695 can be one of the values "rect", "cross", "ellipse", "custom".
2697 If the value for @var{shape} is "custom", it must be followed by a
2698 string of the form "=@var{filename}". The file with name
2699 @var{filename} is assumed to represent a binary image, with each
2700 printable character corresponding to a bright pixel. When a custom
2701 @var{shape} is used, @var{cols} and @var{rows} are ignored, the number
2702 or columns and rows of the read file are assumed instead.
2704 The default value for @var{struct_el} is "3x3+0x0/rect".
2706 @var{nb_iterations} specifies the number of times the transform is
2707 applied to the image, and defaults to 1.
2709 Follow some example:
2711 # use the default values
2714 # dilate using a structuring element with a 5x5 cross, iterate two times
2715 ocv=dilate=5x5+2x2/cross:2
2717 # read the shape from the file diamond.shape, iterate two times
2718 # the file diamond.shape may contain a pattern of characters like this:
2724 # the specified cols and rows are ignored (but not the anchor point coordinates)
2725 ocv=0x0+2x2/custom=diamond.shape:2
2730 Erode an image by using a specific structuring element.
2731 This filter corresponds to the libopencv function @code{cvErode}.
2733 The filter accepts the parameters: @var{struct_el}:@var{nb_iterations},
2734 with the same syntax and semantics as the @ref{dilate} filter.
2738 Smooth the input video.
2740 The filter takes the following parameters:
2741 @var{type}:@var{param1}:@var{param2}:@var{param3}:@var{param4}.
2743 @var{type} is the type of smooth filter to apply, and can be one of
2744 the following values: "blur", "blur_no_scale", "median", "gaussian",
2745 "bilateral". The default value is "gaussian".
2747 @var{param1}, @var{param2}, @var{param3}, and @var{param4} are
2748 parameters whose meanings depend on smooth type. @var{param1} and
2749 @var{param2} accept integer positive values or 0, @var{param3} and
2750 @var{param4} accept float values.
2752 The default value for @var{param1} is 3, the default value for the
2753 other parameters is 0.
2755 These parameters correspond to the parameters assigned to the
2756 libopencv function @code{cvSmooth}.
2761 Overlay one video on top of another.
2763 It takes two inputs and one output, the first input is the "main"
2764 video on which the second input is overlayed.
2766 It accepts the parameters: @var{x}:@var{y}[:@var{options}].
2768 @var{x} is the x coordinate of the overlayed video on the main video,
2769 @var{y} is the y coordinate. @var{x} and @var{y} are expressions containing
2770 the following parameters:
2773 @item main_w, main_h
2774 main input width and height
2777 same as @var{main_w} and @var{main_h}
2779 @item overlay_w, overlay_h
2780 overlay input width and height
2783 same as @var{overlay_w} and @var{overlay_h}
2786 @var{options} is an optional list of @var{key}=@var{value} pairs,
2789 The description of the accepted options follows.
2793 If set to 1, force the filter to accept inputs in the RGB
2794 color space. Default value is 0.
2797 Be aware that frames are taken from each input video in timestamp
2798 order, hence, if their initial timestamps differ, it is a a good idea
2799 to pass the two inputs through a @var{setpts=PTS-STARTPTS} filter to
2800 have them begin in the same zero timestamp, as it does the example for
2801 the @var{movie} filter.
2803 Follow some examples:
2805 # draw the overlay at 10 pixels from the bottom right
2806 # corner of the main video.
2807 overlay=main_w-overlay_w-10:main_h-overlay_h-10
2809 # insert a transparent PNG logo in the bottom left corner of the input
2810 ffmpeg -i input -i logo -filter_complex 'overlay=10:main_h-overlay_h-10' output
2812 # insert 2 different transparent PNG logos (second logo on bottom
2814 ffmpeg -i input -i logo1 -i logo2 -filter_complex
2815 'overlay=10:H-h-10,overlay=W-w-10:H-h-10' output
2817 # add a transparent color layer on top of the main video,
2818 # WxH specifies the size of the main input to the overlay filter
2819 color=red@.3:WxH [over]; [in][over] overlay [out]
2821 # play an original video and a filtered version (here with the deshake filter)
2823 ffplay input.avi -vf 'split[a][b]; [a]pad=iw*2:ih[src]; [b]deshake[filt]; [src][filt]overlay=w'
2825 # the previous example is the same as:
2826 ffplay input.avi -vf 'split[b], pad=iw*2[src], [b]deshake, [src]overlay=w'
2829 You can chain together more overlays but the efficiency of such
2830 approach is yet to be tested.
2834 Add paddings to the input image, and places the original input at the
2835 given coordinates @var{x}, @var{y}.
2837 It accepts the following parameters:
2838 @var{width}:@var{height}:@var{x}:@var{y}:@var{color}.
2840 The parameters @var{width}, @var{height}, @var{x}, and @var{y} are
2841 expressions containing the following constants:
2845 the input video width and height
2848 same as @var{in_w} and @var{in_h}
2851 the output width and height, that is the size of the padded area as
2852 specified by the @var{width} and @var{height} expressions
2855 same as @var{out_w} and @var{out_h}
2858 x and y offsets as specified by the @var{x} and @var{y}
2859 expressions, or NAN if not yet specified
2862 same as @var{iw} / @var{ih}
2865 input sample aspect ratio
2868 input display aspect ratio, it is the same as (@var{iw} / @var{ih}) * @var{sar}
2871 horizontal and vertical chroma subsample values. For example for the
2872 pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
2875 Follows the description of the accepted parameters.
2880 Specify the size of the output image with the paddings added. If the
2881 value for @var{width} or @var{height} is 0, the corresponding input size
2882 is used for the output.
2884 The @var{width} expression can reference the value set by the
2885 @var{height} expression, and vice versa.
2887 The default value of @var{width} and @var{height} is 0.
2891 Specify the offsets where to place the input image in the padded area
2892 with respect to the top/left border of the output image.
2894 The @var{x} expression can reference the value set by the @var{y}
2895 expression, and vice versa.
2897 The default value of @var{x} and @var{y} is 0.
2901 Specify the color of the padded area, it can be the name of a color
2902 (case insensitive match) or a 0xRRGGBB[AA] sequence.
2904 The default value of @var{color} is "black".
2912 Add paddings with color "violet" to the input video. Output video
2913 size is 640x480, the top-left corner of the input video is placed at
2916 pad=640:480:0:40:violet
2920 Pad the input to get an output with dimensions increased by 3/2,
2921 and put the input video at the center of the padded area:
2923 pad="3/2*iw:3/2*ih:(ow-iw)/2:(oh-ih)/2"
2927 Pad the input to get a squared output with size equal to the maximum
2928 value between the input width and height, and put the input video at
2929 the center of the padded area:
2931 pad="max(iw\,ih):ow:(ow-iw)/2:(oh-ih)/2"
2935 Pad the input to get a final w/h ratio of 16:9:
2937 pad="ih*16/9:ih:(ow-iw)/2:(oh-ih)/2"
2941 In case of anamorphic video, in order to set the output display aspect
2942 correctly, it is necessary to use @var{sar} in the expression,
2943 according to the relation:
2945 (ih * X / ih) * sar = output_dar
2946 X = output_dar / sar
2949 Thus the previous example needs to be modified to:
2951 pad="ih*16/9/sar:ih:(ow-iw)/2:(oh-ih)/2"
2955 Double output size and put the input video in the bottom-right
2956 corner of the output padded area:
2958 pad="2*iw:2*ih:ow-iw:oh-ih"
2962 @section pixdesctest
2964 Pixel format descriptor test filter, mainly useful for internal
2965 testing. The output video should be equal to the input video.
2969 format=monow, pixdesctest
2972 can be used to test the monowhite pixel format descriptor definition.
2976 Suppress a TV station logo, using an image file to determine which
2977 pixels comprise the logo. It works by filling in the pixels that
2978 comprise the logo with neighboring pixels.
2980 This filter requires one argument which specifies the filter bitmap
2981 file, which can be any image format supported by libavformat. The
2982 width and height of the image file must match those of the video
2983 stream being processed.
2985 Pixels in the provided bitmap image with a value of zero are not
2986 considered part of the logo, non-zero pixels are considered part of
2987 the logo. If you use white (255) for the logo and black (0) for the
2988 rest, you will be safe. For making the filter bitmap, it is
2989 recommended to take a screen capture of a black frame with the logo
2990 visible, and then using a threshold filter followed by the erode
2991 filter once or twice.
2993 If needed, little splotches can be fixed manually. Remember that if
2994 logo pixels are not covered, the filter quality will be much
2995 reduced. Marking too many pixels as part of the logo does not hurt as
2996 much, but it will increase the amount of blurring needed to cover over
2997 the image and will destroy more information than necessary, and extra
2998 pixels will slow things down on a large logo.
3002 Scale the input video to @var{width}:@var{height}[:@var{interl}=@{1|-1@}] and/or convert the image format.
3004 The scale filter forces the output display aspect ratio to be the same
3005 of the input, by changing the output sample aspect ratio.
3007 The parameters @var{width} and @var{height} are expressions containing
3008 the following constants:
3012 the input width and height
3015 same as @var{in_w} and @var{in_h}
3018 the output (cropped) width and height
3021 same as @var{out_w} and @var{out_h}
3024 same as @var{iw} / @var{ih}
3027 input sample aspect ratio
3030 input display aspect ratio, it is the same as (@var{iw} / @var{ih}) * @var{sar}
3033 horizontal and vertical chroma subsample values. For example for the
3034 pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
3037 If the input image format is different from the format requested by
3038 the next filter, the scale filter will convert the input to the
3041 If the value for @var{width} or @var{height} is 0, the respective input
3042 size is used for the output.
3044 If the value for @var{width} or @var{height} is -1, the scale filter will
3045 use, for the respective output size, a value that maintains the aspect
3046 ratio of the input image.
3048 The default value of @var{width} and @var{height} is 0.
3050 Valid values for the optional parameter @var{interl} are:
3054 force interlaced aware scaling
3057 select interlaced aware scaling depending on whether the source frames
3058 are flagged as interlaced or not
3061 Unless @var{interl} is set to one of the above options, interlaced scaling will not be used.
3063 Some examples follow:
3065 # scale the input video to a size of 200x100.
3068 # scale the input to 2x
3070 # the above is the same as
3073 # scale the input to 2x with forced interlaced scaling
3074 scale=2*iw:2*ih:interl=1
3076 # scale the input to half size
3079 # increase the width, and set the height to the same size
3082 # seek for Greek harmony
3086 # increase the height, and set the width to 3/2 of the height
3089 # increase the size, but make the size a multiple of the chroma
3090 scale="trunc(3/2*iw/hsub)*hsub:trunc(3/2*ih/vsub)*vsub"
3092 # increase the width to a maximum of 500 pixels, keep the same input aspect ratio
3093 scale='min(500\, iw*3/2):-1'
3097 Select frames to pass in output.
3099 It accepts in input an expression, which is evaluated for each input
3100 frame. If the expression is evaluated to a non-zero value, the frame
3101 is selected and passed to the output, otherwise it is discarded.
3103 The expression can contain the following constants:
3107 the sequential number of the filtered frame, starting from 0
3110 the sequential number of the selected frame, starting from 0
3112 @item prev_selected_n
3113 the sequential number of the last selected frame, NAN if undefined
3116 timebase of the input timestamps
3119 the PTS (Presentation TimeStamp) of the filtered video frame,
3120 expressed in @var{TB} units, NAN if undefined
3123 the PTS (Presentation TimeStamp) of the filtered video frame,
3124 expressed in seconds, NAN if undefined
3127 the PTS of the previously filtered video frame, NAN if undefined
3129 @item prev_selected_pts
3130 the PTS of the last previously filtered video frame, NAN if undefined
3132 @item prev_selected_t
3133 the PTS of the last previously selected video frame, NAN if undefined
3136 the PTS of the first video frame in the video, NAN if undefined
3139 the time of the first video frame in the video, NAN if undefined
3142 the type of the filtered frame, can assume one of the following
3154 @item interlace_type
3155 the frame interlace type, can assume one of the following values:
3158 the frame is progressive (not interlaced)
3160 the frame is top-field-first
3162 the frame is bottom-field-first
3166 1 if the filtered frame is a key-frame, 0 otherwise
3169 the position in the file of the filtered frame, -1 if the information
3170 is not available (e.g. for synthetic video)
3173 value between 0 and 1 to indicate a new scene; a low value reflects a low
3174 probability for the current frame to introduce a new scene, while a higher
3175 value means the current frame is more likely to be one (see the example below)
3179 The default value of the select expression is "1".
3181 Some examples follow:
3184 # select all frames in input
3187 # the above is the same as:
3193 # select only I-frames
3194 select='eq(pict_type\,I)'
3196 # select one frame every 100
3197 select='not(mod(n\,100))'
3199 # select only frames contained in the 10-20 time interval
3200 select='gte(t\,10)*lte(t\,20)'
3202 # select only I frames contained in the 10-20 time interval
3203 select='gte(t\,10)*lte(t\,20)*eq(pict_type\,I)'
3205 # select frames with a minimum distance of 10 seconds
3206 select='isnan(prev_selected_t)+gte(t-prev_selected_t\,10)'
3209 Complete example to create a mosaic of the first scenes:
3212 ffmpeg -i video.avi -vf select='gt(scene\,0.4)',scale=160:120,tile -frames:v 1 preview.png
3215 Comparing @var{scene} against a value between 0.3 and 0.5 is generally a sane
3218 @section setdar, setsar
3220 The @code{setdar} filter sets the Display Aspect Ratio for the filter
3223 This is done by changing the specified Sample (aka Pixel) Aspect
3224 Ratio, according to the following equation:
3226 @var{DAR} = @var{HORIZONTAL_RESOLUTION} / @var{VERTICAL_RESOLUTION} * @var{SAR}
3229 Keep in mind that the @code{setdar} filter does not modify the pixel
3230 dimensions of the video frame. Also the display aspect ratio set by
3231 this filter may be changed by later filters in the filterchain,
3232 e.g. in case of scaling or if another "setdar" or a "setsar" filter is
3235 The @code{setsar} filter sets the Sample (aka Pixel) Aspect Ratio for
3236 the filter output video.
3238 Note that as a consequence of the application of this filter, the
3239 output display aspect ratio will change according to the equation
3242 Keep in mind that the sample aspect ratio set by the @code{setsar}
3243 filter may be changed by later filters in the filterchain, e.g. if
3244 another "setsar" or a "setdar" filter is applied.
3246 The @code{setdar} and @code{setsar} filters accept a parameter string
3247 which represents the wanted aspect ratio. The parameter can
3248 be a floating point number string, an expression, or a string of the form
3249 @var{num}:@var{den}, where @var{num} and @var{den} are the numerator
3250 and denominator of the aspect ratio. If the parameter is not
3251 specified, it is assumed the value "0:1".
3253 For example to change the display aspect ratio to 16:9, specify:
3258 The example above is equivalent to:
3263 To change the sample aspect ratio to 10:11, specify:
3270 Force field for the output video frame.
3272 The @code{setfield} filter marks the interlace type field for the
3273 output frames. It does not change the input frame, but only sets the
3274 corresponding property, which affects how the frame is treated by
3275 following filters (e.g. @code{fieldorder} or @code{yadif}).
3277 It accepts a string parameter, which can assume the following values:
3280 Keep the same field property.
3283 Mark the frame as bottom-field-first.
3286 Mark the frame as top-field-first.
3289 Mark the frame as progressive.
3294 Show a line containing various information for each input video frame.
3295 The input video is not modified.
3297 The shown line contains a sequence of key/value pairs of the form
3298 @var{key}:@var{value}.
3300 A description of each shown parameter follows:
3304 sequential number of the input frame, starting from 0
3307 Presentation TimeStamp of the input frame, expressed as a number of
3308 time base units. The time base unit depends on the filter input pad.
3311 Presentation TimeStamp of the input frame, expressed as a number of
3315 position of the frame in the input stream, -1 if this information in
3316 unavailable and/or meaningless (for example in case of synthetic video)
3322 sample aspect ratio of the input frame, expressed in the form
3326 size of the input frame, expressed in the form
3327 @var{width}x@var{height}
3330 interlaced mode ("P" for "progressive", "T" for top field first, "B"
3331 for bottom field first)
3334 1 if the frame is a key frame, 0 otherwise
3337 picture type of the input frame ("I" for an I-frame, "P" for a
3338 P-frame, "B" for a B-frame, "?" for unknown type).
3339 Check also the documentation of the @code{AVPictureType} enum and of
3340 the @code{av_get_picture_type_char} function defined in
3341 @file{libavutil/avutil.h}.
3344 Adler-32 checksum (printed in hexadecimal) of all the planes of the input frame
3346 @item plane_checksum
3347 Adler-32 checksum (printed in hexadecimal) of each plane of the input frame,
3348 expressed in the form "[@var{c0} @var{c1} @var{c2} @var{c3}]"
3353 Pass the images of input video on to next video filter as multiple
3357 ffmpeg -i in.avi -vf "slicify=32" out.avi
3360 The filter accepts the slice height as parameter. If the parameter is
3361 not specified it will use the default value of 16.
3363 Adding this in the beginning of filter chains should make filtering
3364 faster due to better use of the memory cache.
3368 Blur the input video without impacting the outlines.
3370 The filter accepts the following parameters:
3371 @var{luma_radius}:@var{luma_strength}:@var{luma_threshold}[:@var{chroma_radius}:@var{chroma_strength}:@var{chroma_threshold}]
3373 Parameters prefixed by @var{luma} indicate that they work on the
3374 luminance of the pixels whereas parameters prefixed by @var{chroma}
3375 refer to the chrominance of the pixels.
3377 If the chroma parameters are not set, the luma parameters are used for
3378 either the luminance and the chrominance of the pixels.
3380 @var{luma_radius} or @var{chroma_radius} must be a float number in the
3381 range [0.1,5.0] that specifies the variance of the gaussian filter
3382 used to blur the image (slower if larger).
3384 @var{luma_strength} or @var{chroma_strength} must be a float number in
3385 the range [-1.0,1.0] that configures the blurring. A value included in
3386 [0.0,1.0] will blur the image whereas a value included in [-1.0,0.0]
3387 will sharpen the image.
3389 @var{luma_threshold} or @var{chroma_threshold} must be an integer in
3390 the range [-30,30] that is used as a coefficient to determine whether
3391 a pixel should be blurred or not. A value of 0 will filter all the
3392 image, a value included in [0,30] will filter flat areas and a value
3393 included in [-30,0] will filter edges.
3397 Split input video into several identical outputs.
3399 The filter accepts a single parameter which specifies the number of outputs. If
3400 unspecified, it defaults to 2.
3404 ffmpeg -i INPUT -filter_complex split=5 OUTPUT
3406 will create 5 copies of the input video.
3410 [in] split [splitout1][splitout2];
3411 [splitout1] crop=100:100:0:0 [cropout];
3412 [splitout2] pad=200:200:100:100 [padout];
3415 will create two separate outputs from the same input, one cropped and
3420 Scale the input by 2x and smooth using the Super2xSaI (Scale and
3421 Interpolate) pixel art scaling algorithm.
3423 Useful for enlarging pixel art images without reducing sharpness.
3429 Select the most representative frame in a given sequence of consecutive frames.
3431 It accepts as argument the frames batch size to analyze (default @var{N}=100);
3432 in a set of @var{N} frames, the filter will pick one of them, and then handle
3433 the next batch of @var{N} frames until the end.
3435 Since the filter keeps track of the whole frames sequence, a bigger @var{N}
3436 value will result in a higher memory usage, so a high value is not recommended.
3438 The following example extract one picture each 50 frames:
3443 Complete example of a thumbnail creation with @command{ffmpeg}:
3445 ffmpeg -i in.avi -vf thumbnail,scale=300:200 -frames:v 1 out.png
3450 Tile several successive frames together.
3452 It accepts as argument the tile size (i.e. the number of lines and columns)
3453 in the form "@var{w}x@var{h}".
3455 For example, produce 8×8 PNG tiles of all keyframes (@option{-skip_frame
3458 ffmpeg -skip_frame nokey -i file.avi -vf 'scale=128:72,tile=8x8' -an -vsync 0 keyframes%03d.png
3460 The @option{-vsync 0} is necessary to prevent @command{ffmpeg} from
3461 duplicating each output frame to accomodate the originally detected frame
3466 Perform various types of temporal field interlacing.
3468 Frames are counted starting from 1, so the first input frame is
3471 This filter accepts a single parameter specifying the mode. Available
3476 Move odd frames into the upper field, even into the lower field,
3477 generating a double height frame at half framerate.
3480 Only output even frames, odd frames are dropped, generating a frame with
3481 unchanged height at half framerate.
3484 Only output odd frames, even frames are dropped, generating a frame with
3485 unchanged height at half framerate.
3488 Expand each frame to full height, but pad alternate lines with black,
3489 generating a frame with double height at the same input framerate.
3491 @item interleave_top, 4
3492 Interleave the upper field from odd frames with the lower field from
3493 even frames, generating a frame with unchanged height at half framerate.
3495 @item interleave_bottom, 5
3496 Interleave the lower field from odd frames with the upper field from
3497 even frames, generating a frame with unchanged height at half framerate.
3499 @item interlacex2, 6
3500 Double frame rate with unchanged height. Frames are inserted each
3501 containing the second temporal field from the previous input frame and
3502 the first temporal field from the next input frame. This mode relies on
3503 the top_field_first flag. Useful for interlaced video displays with no
3504 field synchronisation.
3507 Numeric values are deprecated but are accepted for backward
3508 compatibility reasons.
3510 Default mode is @code{merge}.
3514 Transpose rows with columns in the input video and optionally flip it.
3516 This filter accepts the following named parameters:
3520 Specify the transposition direction. Can assume the following values:
3524 Rotate by 90 degrees counterclockwise and vertically flip (default), that is:
3532 Rotate by 90 degrees clockwise, that is:
3540 Rotate by 90 degrees counterclockwise, that is:
3548 Rotate by 90 degrees clockwise and vertically flip, that is:
3556 For values between 4-7, the transposition is only done if the input
3557 video geometry is portrait and not landscape. These values are
3558 deprecated, the @code{passthrough} option should be used instead.
3561 Do not apply the transposition if the input geometry matches the one
3562 specified by the specified value. It accepts the following values:
3565 Always apply transposition.
3567 Preserve portrait geometry (when @var{height} >= @var{width}).
3569 Preserve landscape geometry (when @var{width} >= @var{height}).
3572 Default value is @code{none}.
3577 Sharpen or blur the input video.
3579 It accepts the following parameters:
3580 @var{luma_msize_x}:@var{luma_msize_y}:@var{luma_amount}:@var{chroma_msize_x}:@var{chroma_msize_y}:@var{chroma_amount}
3582 Negative values for the amount will blur the input video, while positive
3583 values will sharpen. All parameters are optional and default to the
3584 equivalent of the string '5:5:1.0:5:5:0.0'.
3589 Set the luma matrix horizontal size. It can be an integer between 3
3590 and 13, default value is 5.
3593 Set the luma matrix vertical size. It can be an integer between 3
3594 and 13, default value is 5.
3597 Set the luma effect strength. It can be a float number between -2.0
3598 and 5.0, default value is 1.0.
3600 @item chroma_msize_x
3601 Set the chroma matrix horizontal size. It can be an integer between 3
3602 and 13, default value is 5.
3604 @item chroma_msize_y
3605 Set the chroma matrix vertical size. It can be an integer between 3
3606 and 13, default value is 5.
3609 Set the chroma effect strength. It can be a float number between -2.0
3610 and 5.0, default value is 0.0.
3615 # Strong luma sharpen effect parameters
3618 # Strong blur of both luma and chroma parameters
3619 unsharp=7:7:-2:7:7:-2
3621 # Use the default values with @command{ffmpeg}
3622 ffmpeg -i in.avi -vf "unsharp" out.mp4
3627 Flip the input video vertically.
3630 ffmpeg -i in.avi -vf "vflip" out.avi
3635 Deinterlace the input video ("yadif" means "yet another deinterlacing
3638 It accepts the optional parameters: @var{mode}:@var{parity}:@var{auto}.
3640 @var{mode} specifies the interlacing mode to adopt, accepts one of the
3645 output 1 frame for each frame
3647 output 1 frame for each field
3649 like 0 but skips spatial interlacing check
3651 like 1 but skips spatial interlacing check
3656 @var{parity} specifies the picture field parity assumed for the input
3657 interlaced video, accepts one of the following values:
3661 assume top field first
3663 assume bottom field first
3665 enable automatic detection
3668 Default value is -1.
3669 If interlacing is unknown or decoder does not export this information,
3670 top field first will be assumed.
3672 @var{auto} specifies if deinterlacer should trust the interlaced flag
3673 and only deinterlace frames marked as interlaced
3677 deinterlace all frames
3679 only deinterlace frames marked as interlaced
3684 @c man end VIDEO FILTERS
3686 @chapter Video Sources
3687 @c man begin VIDEO SOURCES
3689 Below is a description of the currently available video sources.
3693 Buffer video frames, and make them available to the filter chain.
3695 This source is mainly intended for a programmatic use, in particular
3696 through the interface defined in @file{libavfilter/vsrc_buffer.h}.
3698 It accepts a list of options in the form of @var{key}=@var{value} pairs
3699 separated by ":". A description of the accepted options follows.
3704 Specify the size (width and height) of the buffered video frames.
3707 A string representing the pixel format of the buffered video frames.
3708 It may be a number corresponding to a pixel format, or a pixel format
3712 Specify the timebase assumed by the timestamps of the buffered frames.
3715 Specify the frame rate expected for the video stream.
3718 Specify the sample aspect ratio assumed by the video frames.
3721 Specify the optional parameters to be used for the scale filter which
3722 is automatically inserted when an input change is detected in the
3723 input size or format.
3728 buffer=size=320x240:pix_fmt=yuv410p:time_base=1/24:pixel_aspect=1/1
3731 will instruct the source to accept video frames with size 320x240 and
3732 with format "yuv410p", assuming 1/24 as the timestamps timebase and
3733 square pixels (1:1 sample aspect ratio).
3734 Since the pixel format with name "yuv410p" corresponds to the number 6
3735 (check the enum AVPixelFormat definition in @file{libavutil/pixfmt.h}),
3736 this example corresponds to:
3738 buffer=size=320x240:pixfmt=6:time_base=1/24:pixel_aspect=1/1
3741 Alternatively, the options can be specified as a flat string, but this
3742 syntax is deprecated:
3744 @var{width}:@var{height}:@var{pix_fmt}:@var{time_base.num}:@var{time_base.den}:@var{pixel_aspect.num}:@var{pixel_aspect.den}[:@var{sws_param}]
3748 Create a pattern generated by an elementary cellular automaton.
3750 The initial state of the cellular automaton can be defined through the
3751 @option{filename}, and @option{pattern} options. If such options are
3752 not specified an initial state is created randomly.
3754 At each new frame a new row in the video is filled with the result of
3755 the cellular automaton next generation. The behavior when the whole
3756 frame is filled is defined by the @option{scroll} option.
3758 This source accepts a list of options in the form of
3759 @var{key}=@var{value} pairs separated by ":". A description of the
3760 accepted options follows.
3764 Read the initial cellular automaton state, i.e. the starting row, from
3766 In the file, each non-whitespace character is considered an alive
3767 cell, a newline will terminate the row, and further characters in the
3768 file will be ignored.
3771 Read the initial cellular automaton state, i.e. the starting row, from
3772 the specified string.
3774 Each non-whitespace character in the string is considered an alive
3775 cell, a newline will terminate the row, and further characters in the
3776 string will be ignored.
3779 Set the video rate, that is the number of frames generated per second.
3782 @item random_fill_ratio, ratio
3783 Set the random fill ratio for the initial cellular automaton row. It
3784 is a floating point number value ranging from 0 to 1, defaults to
3787 This option is ignored when a file or a pattern is specified.
3789 @item random_seed, seed
3790 Set the seed for filling randomly the initial row, must be an integer
3791 included between 0 and UINT32_MAX. If not specified, or if explicitly
3792 set to -1, the filter will try to use a good random seed on a best
3796 Set the cellular automaton rule, it is a number ranging from 0 to 255.
3797 Default value is 110.
3800 Set the size of the output video.
3802 If @option{filename} or @option{pattern} is specified, the size is set
3803 by default to the width of the specified initial state row, and the
3804 height is set to @var{width} * PHI.
3806 If @option{size} is set, it must contain the width of the specified
3807 pattern string, and the specified pattern will be centered in the
3810 If a filename or a pattern string is not specified, the size value
3811 defaults to "320x518" (used for a randomly generated initial state).
3814 If set to 1, scroll the output upward when all the rows in the output
3815 have been already filled. If set to 0, the new generated row will be
3816 written over the top row just after the bottom row is filled.
3819 @item start_full, full
3820 If set to 1, completely fill the output with generated rows before
3821 outputting the first frame.
3822 This is the default behavior, for disabling set the value to 0.
3825 If set to 1, stitch the left and right row edges together.
3826 This is the default behavior, for disabling set the value to 0.
3829 @subsection Examples
3833 Read the initial state from @file{pattern}, and specify an output of
3836 cellauto=f=pattern:s=200x400
3840 Generate a random initial row with a width of 200 cells, with a fill
3843 cellauto=ratio=2/3:s=200x200
3847 Create a pattern generated by rule 18 starting by a single alive cell
3848 centered on an initial row with width 100:
3850 cellauto=p=@@:s=100x400:full=0:rule=18
3854 Specify a more elaborated initial pattern:
3856 cellauto=p='@@@@ @@ @@@@':s=100x400:full=0:rule=18
3863 Generate a Mandelbrot set fractal, and progressively zoom towards the
3864 point specified with @var{start_x} and @var{start_y}.
3866 This source accepts a list of options in the form of
3867 @var{key}=@var{value} pairs separated by ":". A description of the
3868 accepted options follows.
3873 Set the terminal pts value. Default value is 400.
3876 Set the terminal scale value.
3877 Must be a floating point value. Default value is 0.3.
3880 Set the inner coloring mode, that is the algorithm used to draw the
3881 Mandelbrot fractal internal region.
3883 It shall assume one of the following values:
3888 Show time until convergence.
3890 Set color based on point closest to the origin of the iterations.
3895 Default value is @var{mincol}.
3898 Set the bailout value. Default value is 10.0.
3901 Set the maximum of iterations performed by the rendering
3902 algorithm. Default value is 7189.
3905 Set outer coloring mode.
3906 It shall assume one of following values:
3908 @item iteration_count
3909 Set iteration cound mode.
3910 @item normalized_iteration_count
3911 set normalized iteration count mode.
3913 Default value is @var{normalized_iteration_count}.
3916 Set frame rate, expressed as number of frames per second. Default
3920 Set frame size. Default value is "640x480".
3923 Set the initial scale value. Default value is 3.0.
3926 Set the initial x position. Must be a floating point value between
3927 -100 and 100. Default value is -0.743643887037158704752191506114774.
3930 Set the initial y position. Must be a floating point value between
3931 -100 and 100. Default value is -0.131825904205311970493132056385139.
3936 Generate various test patterns, as generated by the MPlayer test filter.
3938 The size of the generated video is fixed, and is 256x256.
3939 This source is useful in particular for testing encoding features.
3941 This source accepts an optional sequence of @var{key}=@var{value} pairs,
3942 separated by ":". The description of the accepted options follows.
3947 Specify the frame rate of the sourced video, as the number of frames
3948 generated per second. It has to be a string in the format
3949 @var{frame_rate_num}/@var{frame_rate_den}, an integer number, a float
3950 number or a valid video frame rate abbreviation. The default value is
3954 Set the video duration of the sourced video. The accepted syntax is:
3959 See also the function @code{av_parse_time()}.
3961 If not specified, or the expressed duration is negative, the video is
3962 supposed to be generated forever.
3966 Set the number or the name of the test to perform. Supported tests are:
3981 Default value is "all", which will cycle through the list of all tests.
3984 For example the following:
3989 will generate a "dc_luma" test pattern.
3993 Provide a frei0r source.
3995 To enable compilation of this filter you need to install the frei0r
3996 header and configure FFmpeg with @code{--enable-frei0r}.
3998 The source supports the syntax:
4000 @var{size}:@var{rate}:@var{src_name}[@{=|:@}@var{param1}:@var{param2}:...:@var{paramN}]
4003 @var{size} is the size of the video to generate, may be a string of the
4004 form @var{width}x@var{height} or a frame size abbreviation.
4005 @var{rate} is the rate of the video to generate, may be a string of
4006 the form @var{num}/@var{den} or a frame rate abbreviation.
4007 @var{src_name} is the name to the frei0r source to load. For more
4008 information regarding frei0r and how to set the parameters read the
4009 section @ref{frei0r} in the description of the video filters.
4011 For example, to generate a frei0r partik0l source with size 200x200
4012 and frame rate 10 which is overlayed on the overlay filter main input:
4014 frei0r_src=200x200:10:partik0l=1234 [overlay]; [in][overlay] overlay
4019 Generate a life pattern.
4021 This source is based on a generalization of John Conway's life game.
4023 The sourced input represents a life grid, each pixel represents a cell
4024 which can be in one of two possible states, alive or dead. Every cell
4025 interacts with its eight neighbours, which are the cells that are
4026 horizontally, vertically, or diagonally adjacent.
4028 At each interaction the grid evolves according to the adopted rule,
4029 which specifies the number of neighbor alive cells which will make a
4030 cell stay alive or born. The @option{rule} option allows to specify
4033 This source accepts a list of options in the form of
4034 @var{key}=@var{value} pairs separated by ":". A description of the
4035 accepted options follows.
4039 Set the file from which to read the initial grid state. In the file,
4040 each non-whitespace character is considered an alive cell, and newline
4041 is used to delimit the end of each row.
4043 If this option is not specified, the initial grid is generated
4047 Set the video rate, that is the number of frames generated per second.
4050 @item random_fill_ratio, ratio
4051 Set the random fill ratio for the initial random grid. It is a
4052 floating point number value ranging from 0 to 1, defaults to 1/PHI.
4053 It is ignored when a file is specified.
4055 @item random_seed, seed
4056 Set the seed for filling the initial random grid, must be an integer
4057 included between 0 and UINT32_MAX. If not specified, or if explicitly
4058 set to -1, the filter will try to use a good random seed on a best
4064 A rule can be specified with a code of the kind "S@var{NS}/B@var{NB}",
4065 where @var{NS} and @var{NB} are sequences of numbers in the range 0-8,
4066 @var{NS} specifies the number of alive neighbor cells which make a
4067 live cell stay alive, and @var{NB} the number of alive neighbor cells
4068 which make a dead cell to become alive (i.e. to "born").
4069 "s" and "b" can be used in place of "S" and "B", respectively.
4071 Alternatively a rule can be specified by an 18-bits integer. The 9
4072 high order bits are used to encode the next cell state if it is alive
4073 for each number of neighbor alive cells, the low order bits specify
4074 the rule for "borning" new cells. Higher order bits encode for an
4075 higher number of neighbor cells.
4076 For example the number 6153 = @code{(12<<9)+9} specifies a stay alive
4077 rule of 12 and a born rule of 9, which corresponds to "S23/B03".
4079 Default value is "S23/B3", which is the original Conway's game of life
4080 rule, and will keep a cell alive if it has 2 or 3 neighbor alive
4081 cells, and will born a new cell if there are three alive cells around
4085 Set the size of the output video.
4087 If @option{filename} is specified, the size is set by default to the
4088 same size of the input file. If @option{size} is set, it must contain
4089 the size specified in the input file, and the initial grid defined in
4090 that file is centered in the larger resulting area.
4092 If a filename is not specified, the size value defaults to "320x240"
4093 (used for a randomly generated initial grid).
4096 If set to 1, stitch the left and right grid edges together, and the
4097 top and bottom edges also. Defaults to 1.
4100 Set cell mold speed. If set, a dead cell will go from @option{death_color} to
4101 @option{mold_color} with a step of @option{mold}. @option{mold} can have a
4102 value from 0 to 255.
4105 Set the color of living (or new born) cells.
4108 Set the color of dead cells. If @option{mold} is set, this is the first color
4109 used to represent a dead cell.
4112 Set mold color, for definitely dead and moldy cells.
4115 @subsection Examples
4119 Read a grid from @file{pattern}, and center it on a grid of size
4122 life=f=pattern:s=300x300
4126 Generate a random grid of size 200x200, with a fill ratio of 2/3:
4128 life=ratio=2/3:s=200x200
4132 Specify a custom rule for evolving a randomly generated grid:
4138 Full example with slow death effect (mold) using @command{ffplay}:
4140 ffplay -f lavfi life=s=300x200:mold=10:r=60:ratio=0.1:death_color=#C83232:life_color=#00ff00,scale=1200:800:flags=16
4144 @section color, nullsrc, rgbtestsrc, smptebars, testsrc
4146 The @code{color} source provides an uniformly colored input.
4148 The @code{nullsrc} source returns unprocessed video frames. It is
4149 mainly useful to be employed in analysis / debugging tools, or as the
4150 source for filters which ignore the input data.
4152 The @code{rgbtestsrc} source generates an RGB test pattern useful for
4153 detecting RGB vs BGR issues. You should see a red, green and blue
4154 stripe from top to bottom.
4156 The @code{smptebars} source generates a color bars pattern, based on
4157 the SMPTE Engineering Guideline EG 1-1990.
4159 The @code{testsrc} source generates a test video pattern, showing a
4160 color pattern, a scrolling gradient and a timestamp. This is mainly
4161 intended for testing purposes.
4163 These sources accept an optional sequence of @var{key}=@var{value} pairs,
4164 separated by ":". The description of the accepted options follows.
4169 Specify the color of the source, only used in the @code{color}
4170 source. It can be the name of a color (case insensitive match) or a
4171 0xRRGGBB[AA] sequence, possibly followed by an alpha specifier. The
4172 default value is "black".
4175 Specify the size of the sourced video, it may be a string of the form
4176 @var{width}x@var{height}, or the name of a size abbreviation. The
4177 default value is "320x240".
4180 Specify the frame rate of the sourced video, as the number of frames
4181 generated per second. It has to be a string in the format
4182 @var{frame_rate_num}/@var{frame_rate_den}, an integer number, a float
4183 number or a valid video frame rate abbreviation. The default value is
4187 Set the sample aspect ratio of the sourced video.
4190 Set the video duration of the sourced video. The accepted syntax is:
4192 [-]HH[:MM[:SS[.m...]]]
4195 See also the function @code{av_parse_time()}.
4197 If not specified, or the expressed duration is negative, the video is
4198 supposed to be generated forever.
4201 Set the number of decimals to show in the timestamp, only used in the
4202 @code{testsrc} source.
4204 The displayed timestamp value will correspond to the original
4205 timestamp value multiplied by the power of 10 of the specified
4206 value. Default value is 0.
4209 For example the following:
4211 testsrc=duration=5.3:size=qcif:rate=10
4214 will generate a video with a duration of 5.3 seconds, with size
4215 176x144 and a frame rate of 10 frames per second.
4217 The following graph description will generate a red source
4218 with an opacity of 0.2, with size "qcif" and a frame rate of 10
4221 color=c=red@@0.2:s=qcif:r=10
4224 If the input content is to be ignored, @code{nullsrc} can be used. The
4225 following command generates noise in the luminance plane by employing
4226 the @code{mp=geq} filter:
4228 nullsrc=s=256x256, mp=geq=random(1)*255:128:128
4231 @c man end VIDEO SOURCES
4233 @chapter Video Sinks
4234 @c man begin VIDEO SINKS
4236 Below is a description of the currently available video sinks.
4240 Buffer video frames, and make them available to the end of the filter
4243 This sink is mainly intended for a programmatic use, in particular
4244 through the interface defined in @file{libavfilter/buffersink.h}.
4246 It does not require a string parameter in input, but you need to
4247 specify a pointer to a list of supported pixel formats terminated by
4248 -1 in the opaque parameter provided to @code{avfilter_init_filter}
4249 when initializing this sink.
4253 Null video sink, do absolutely nothing with the input video. It is
4254 mainly useful as a template and to be employed in analysis / debugging
4257 @c man end VIDEO SINKS
4259 @chapter Multimedia Filters
4260 @c man begin MULTIMEDIA FILTERS
4262 Below is a description of the currently available multimedia filters.
4264 @section asendcmd, sendcmd
4266 Send commands to filters in the filtergraph.
4268 These filters read commands to be sent to other filters in the
4271 @code{asendcmd} must be inserted between two audio filters,
4272 @code{sendcmd} must be inserted between two video filters, but apart
4273 from that they act the same way.
4275 The specification of commands can be provided in the filter arguments
4276 with the @var{commands} option, or in a file specified by the
4277 @var{filename} option.
4279 These filters accept the following options:
4282 Set the commands to be read and sent to the other filters.
4284 Set the filename of the commands to be read and sent to the other
4288 @subsection Commands syntax
4290 A commands description consists of a sequence of interval
4291 specifications, comprising a list of commands to be executed when a
4292 particular event related to that interval occurs. The occurring event
4293 is typically the current frame time entering or leaving a given time
4296 An interval is specified by the following syntax:
4298 @var{START}[-@var{END}] @var{COMMANDS};
4301 The time interval is specified by the @var{START} and @var{END} times.
4302 @var{END} is optional and defaults to the maximum time.
4304 The current frame time is considered within the specified interval if
4305 it is included in the interval [@var{START}, @var{END}), that is when
4306 the time is greater or equal to @var{START} and is lesser than
4309 @var{COMMANDS} consists of a sequence of one or more command
4310 specifications, separated by ",", relating to that interval. The
4311 syntax of a command specification is given by:
4313 [@var{FLAGS}] @var{TARGET} @var{COMMAND} @var{ARG}
4316 @var{FLAGS} is optional and specifies the type of events relating to
4317 the time interval which enable sending the specified command, and must
4318 be a non-null sequence of identifier flags separated by "+" or "|" and
4319 enclosed between "[" and "]".
4321 The following flags are recognized:
4324 The command is sent when the current frame timestamp enters the
4325 specified interval. In other words, the command is sent when the
4326 previous frame timestamp was not in the given interval, and the
4330 The command is sent when the current frame timestamp leaves the
4331 specified interval. In other words, the command is sent when the
4332 previous frame timestamp was in the given interval, and the
4336 If @var{FLAGS} is not specified, a default value of @code{[enter]} is
4339 @var{TARGET} specifies the target of the command, usually the name of
4340 the filter class or a specific filter instance name.
4342 @var{COMMAND} specifies the name of the command for the target filter.
4344 @var{ARG} is optional and specifies the optional list of argument for
4345 the given @var{COMMAND}.
4347 Between one interval specification and another, whitespaces, or
4348 sequences of characters starting with @code{#} until the end of line,
4349 are ignored and can be used to annotate comments.
4351 A simplified BNF description of the commands specification syntax
4354 @var{COMMAND_FLAG} ::= "enter" | "leave"
4355 @var{COMMAND_FLAGS} ::= @var{COMMAND_FLAG} [(+|"|")@var{COMMAND_FLAG}]
4356 @var{COMMAND} ::= ["[" @var{COMMAND_FLAGS} "]"] @var{TARGET} @var{COMMAND} [@var{ARG}]
4357 @var{COMMANDS} ::= @var{COMMAND} [,@var{COMMANDS}]
4358 @var{INTERVAL} ::= @var{START}[-@var{END}] @var{COMMANDS}
4359 @var{INTERVALS} ::= @var{INTERVAL}[;@var{INTERVALS}]
4362 @subsection Examples
4366 Specify audio tempo change at second 4:
4368 asendcmd=c='4.0 atempo tempo 1.5',atempo
4372 Specify a list of drawtext and hue commands in a file.
4374 # show text in the interval 5-10
4375 5.0-10.0 [enter] drawtext reinit 'fontfile=FreeSerif.ttf:text=hello world',
4376 [leave] drawtext reinit 'fontfile=FreeSerif.ttf:text=';
4378 # desaturate the image in the interval 15-20
4379 15.0-20.0 [enter] hue reinit s=0,
4380 [enter] drawtext reinit 'fontfile=FreeSerif.ttf:text=nocolor',
4381 [leave] hue reinit s=1,
4382 [leave] drawtext reinit 'fontfile=FreeSerif.ttf:text=color';
4384 # apply an exponential saturation fade-out effect, starting from time 25
4385 25 [enter] hue s=exp(t-25)
4388 A filtergraph allowing to read and process the above command list
4389 stored in a file @file{test.cmd}, can be specified with:
4391 sendcmd=f=test.cmd,drawtext=fontfile=FreeSerif.ttf:text='',hue
4395 @section asetpts, setpts
4397 Change the PTS (presentation timestamp) of the input frames.
4399 @code{asetpts} works on audio frames, @code{setpts} on video frames.
4401 Accept in input an expression evaluated through the eval API, which
4402 can contain the following constants:
4406 frame rate, only defined for constant frame-rate video
4409 the presentation timestamp in input
4412 the count of the input frame, starting from 0.
4414 @item NB_CONSUMED_SAMPLES
4415 the number of consumed samples, not including the current frame (only
4419 the number of samples in the current frame (only audio)
4425 the PTS of the first frame
4428 the time in seconds of the first frame
4431 tell if the current frame is interlaced
4434 the time in seconds of the current frame
4440 original position in the file of the frame, or undefined if undefined
4441 for the current frame
4447 previous input time in seconds
4453 previous output time in seconds
4456 @subsection Examples
4460 Start counting PTS from zero
4466 Apply fast motion effect:
4472 Apply slow motion effect:
4478 Set fixed rate of 25 frames per second:
4484 Set fixed rate 25 fps with some jitter:
4486 setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))'
4490 Apply an offset of 10 seconds to the input PTS:
4498 EBU R128 scanner filter. This filter takes an audio stream as input and outputs
4499 it unchanged. By default, it logs a message at a frequency of 10Hz with the
4500 Momentary loudness (identified by @code{M}), Short-term loudness (@code{S}),
4501 Integrated loudness (@code{I}) and Loudness Range (@code{LRA}).
4503 The filter also has a video output (see the @var{video} option) with a real
4504 time graph to observe the loudness evolution. The graphic contains the logged
4505 message mentioned above, so it is not printed anymore when this option is set,
4506 unless the verbose logging is set. The main graphing area contains the
4507 short-term loudness (3 seconds of analysis), and the gauge on the right is for
4508 the momentary loudness (400 milliseconds).
4510 More information about the Loudness Recommendation EBU R128 on
4511 @url{http://tech.ebu.ch/loudness}.
4513 The filter accepts the following named parameters:
4518 Activate the video output. The audio stream is passed unchanged whether this
4519 option is set or no. The video stream will be the first output stream if
4520 activated. Default is @code{0}.
4523 Set the video size. This option is for video only. Default and minimum
4524 resolution is @code{640x480}.
4527 Set the EBU scale meter. Default is @code{9}. Common values are @code{9} and
4528 @code{18}, respectively for EBU scale meter +9 and EBU scale meter +18. Any
4529 other integer value between this range is allowed.
4533 Example of real-time graph using @command{ffplay}, with a EBU scale meter +18:
4535 ffplay -f lavfi -i "amovie=input.mp3,ebur128=video=1:meter=18 [out0][out1]"
4538 Run an analysis with @command{ffmpeg}:
4540 ffmpeg -nostats -i input.mp3 -filter_complex ebur128 -f null -
4543 @section settb, asettb
4545 Set the timebase to use for the output frames timestamps.
4546 It is mainly useful for testing timebase configuration.
4548 It accepts in input an arithmetic expression representing a rational.
4549 The expression can contain the constants "AVTB" (the
4550 default timebase), "intb" (the input timebase) and "sr" (the sample rate,
4553 The default value for the input is "intb".
4555 @subsection Examples
4559 Set the timebase to 1/25:
4565 Set the timebase to 1/10:
4571 Set the timebase to 1001/1000:
4577 Set the timebase to 2*intb:
4583 Set the default timebase value:
4591 Concatenate audio and video streams, joining them together one after the
4594 The filter works on segments of synchronized video and audio streams. All
4595 segments must have the same number of streams of each type, and that will
4596 also be the number of streams at output.
4598 The filter accepts the following named parameters:
4602 Set the number of segments. Default is 2.
4605 Set the number of output video streams, that is also the number of video
4606 streams in each segment. Default is 1.
4609 Set the number of output audio streams, that is also the number of video
4610 streams in each segment. Default is 0.
4614 The filter has @var{v}+@var{a} outputs: first @var{v} video outputs, then
4615 @var{a} audio outputs.
4617 There are @var{n}×(@var{v}+@var{a}) inputs: first the inputs for the first
4618 segment, in the same order as the outputs, then the inputs for the second
4621 Related streams do not always have exactly the same duration, for various
4622 reasons including codec frame size or sloppy authoring. For that reason,
4623 related synchronized streams (e.g. a video and its audio track) should be
4624 concatenated at once. The concat filter will use the duration of the longest
4625 stream in each segment (except the last one), and if necessary pad shorter
4626 audio streams with silence.
4628 For this filter to work correctly, all segments must start at timestamp 0.
4630 All corresponding streams must have the same parameters in all segments; the
4631 filtering system will automatically select a common pixel format for video
4632 streams, and a common sample format, sample rate and channel layout for
4633 audio streams, but other settings, such as resolution, must be converted
4634 explicitly by the user.
4636 Different frame rates are acceptable but will result in variable frame rate
4637 at output; be sure to configure the output file to handle it.
4642 Concatenate an opening, an episode and an ending, all in bilingual version
4643 (video in stream 0, audio in streams 1 and 2):
4645 ffmpeg -i opening.mkv -i episode.mkv -i ending.mkv -filter_complex \
4646 '[0:0] [0:1] [0:2] [1:0] [1:1] [1:2] [2:0] [2:1] [2:2]
4647 concat=n=3:v=1:a=2 [v] [a1] [a2]' \
4648 -map '[v]' -map '[a1]' -map '[a2]' output.mkv
4652 Concatenate two parts, handling audio and video separately, using the
4653 (a)movie sources, and adjusting the resolution:
4655 movie=part1.mp4, scale=512:288 [v1] ; amovie=part1.mp4 [a1] ;
4656 movie=part2.mp4, scale=512:288 [v2] ; amovie=part2.mp4 [a2] ;
4657 [v1] [v2] concat [outv] ; [a1] [a2] concat=v=0:a=1 [outa]
4659 Note that a desync will happen at the stitch if the audio and video streams
4660 do not have exactly the same duration in the first file.
4664 @section showspectrum
4666 Convert input audio to a video output, representing the audio frequency
4669 The filter accepts the following named parameters:
4672 Specify the video size for the output. Default value is @code{640x480}.
4675 The usage is very similar to the showwaves filter; see the examples in that
4680 Convert input audio to a video output, representing the samples waves.
4682 The filter accepts the following named parameters:
4686 Set the number of samples which are printed on the same column. A
4687 larger value will decrease the frame rate. Must be a positive
4688 integer. This option can be set only if the value for @var{rate}
4689 is not explicitly specified.
4692 Set the (approximate) output frame rate. This is done by setting the
4693 option @var{n}. Default value is "25".
4696 Specify the video size for the output. Default value is "600x240".
4699 Some examples follow.
4702 Output the input file audio and the corresponding video representation
4705 amovie=a.mp3,asplit[out0],showwaves[out1]
4709 Create a synthetic signal and show it with showwaves, forcing a
4710 framerate of 30 frames per second:
4712 aevalsrc=sin(1*2*PI*t)*sin(880*2*PI*t):cos(2*PI*200*t),asplit[out0],showwaves=r=30[out1]
4716 @c man end MULTIMEDIA FILTERS
4718 @chapter Multimedia Sources
4719 @c man begin MULTIMEDIA SOURCES
4721 Below is a description of the currently available multimedia sources.
4725 This is the same as @ref{src_movie} source, except it selects an audio
4731 Read audio and/or video stream(s) from a movie container.
4733 It accepts the syntax: @var{movie_name}[:@var{options}] where
4734 @var{movie_name} is the name of the resource to read (not necessarily
4735 a file but also a device or a stream accessed through some protocol),
4736 and @var{options} is an optional sequence of @var{key}=@var{value}
4737 pairs, separated by ":".
4739 The description of the accepted options follows.
4743 @item format_name, f
4744 Specifies the format assumed for the movie to read, and can be either
4745 the name of a container or an input device. If not specified the
4746 format is guessed from @var{movie_name} or by probing.
4748 @item seek_point, sp
4749 Specifies the seek point in seconds, the frames will be output
4750 starting from this seek point, the parameter is evaluated with
4751 @code{av_strtod} so the numerical value may be suffixed by an IS
4752 postfix. Default value is "0".
4755 Specifies the streams to read. Several streams can be specified, separated
4756 by "+". The source will then have as many outputs, in the same order. The
4757 syntax is explained in the @ref{Stream specifiers} chapter. Two special
4758 names, "dv" and "da" specify respectively the default (best suited) video
4759 and audio stream. Default is "dv", or "da" if the filter is called as
4762 @item stream_index, si
4763 Specifies the index of the video stream to read. If the value is -1,
4764 the best suited video stream will be automatically selected. Default
4765 value is "-1". Deprecated. If the filter is called "amovie", it will select
4766 audio instead of video.
4769 Specifies how many times to read the stream in sequence.
4770 If the value is less than 1, the stream will be read again and again.
4771 Default value is "1".
4773 Note that when the movie is looped the source timestamps are not
4774 changed, so it will generate non monotonically increasing timestamps.
4777 This filter allows to overlay a second video on top of main input of
4778 a filtergraph as shown in this graph:
4780 input -----------> deltapts0 --> overlay --> output
4783 movie --> scale--> deltapts1 -------+
4786 Some examples follow.
4790 Skip 3.2 seconds from the start of the avi file in.avi, and overlay it
4791 on top of the input labelled as "in":
4793 movie=in.avi:seek_point=3.2, scale=180:-1, setpts=PTS-STARTPTS [movie];
4794 [in] setpts=PTS-STARTPTS, [movie] overlay=16:16 [out]
4798 Read from a video4linux2 device, and overlay it on top of the input
4801 movie=/dev/video0:f=video4linux2, scale=180:-1, setpts=PTS-STARTPTS [movie];
4802 [in] setpts=PTS-STARTPTS, [movie] overlay=16:16 [out]
4806 Read the first video stream and the audio stream with id 0x81 from
4807 dvd.vob; the video is connected to the pad named "video" and the audio is
4808 connected to the pad named "audio":
4810 movie=dvd.vob:s=v:0+#0x81 [video] [audio]
4814 @c man end MULTIMEDIA SOURCES