1 @chapter Filtergraph description
2 @c man begin FILTERGRAPH DESCRIPTION
4 A filtergraph is a directed graph of connected filters. It can contain
5 cycles, and there can be multiple links between a pair of
6 filters. Each link has one input pad on one side connecting it to one
7 filter from which it takes its input, and one output pad on the other
8 side connecting it to the one filter accepting its output.
10 Each filter in a filtergraph is an instance of a filter class
11 registered in the application, which defines the features and the
12 number of input and output pads of the filter.
14 A filter with no input pads is called a "source", a filter with no
15 output pads is called a "sink".
17 @section Filtergraph syntax
19 A filtergraph can be represented using a textual representation, which
20 is recognized by the @code{-vf} and @code{-af} options of the ff*
21 tools, and by the @code{avfilter_graph_parse()} function defined in
22 @file{libavfilter/avfiltergraph.h}.
24 A filterchain consists of a sequence of connected filters, each one
25 connected to the previous one in the sequence. A filterchain is
26 represented by a list of ","-separated filter descriptions.
28 A filtergraph consists of a sequence of filterchains. A sequence of
29 filterchains is represented by a list of ";"-separated filterchain
32 A filter is represented by a string of the form:
33 [@var{in_link_1}]...[@var{in_link_N}]@var{filter_name}=@var{arguments}[@var{out_link_1}]...[@var{out_link_M}]
35 @var{filter_name} is the name of the filter class of which the
36 described filter is an instance of, and has to be the name of one of
37 the filter classes registered in the program.
38 The name of the filter class is optionally followed by a string
41 @var{arguments} is a string which contains the parameters used to
42 initialize the filter instance, and are described in the filter
45 The list of arguments can be quoted using the character "'" as initial
46 and ending mark, and the character '\' for escaping the characters
47 within the quoted text; otherwise the argument string is considered
48 terminated when the next special character (belonging to the set
49 "[]=;,") is encountered.
51 The name and arguments of the filter are optionally preceded and
52 followed by a list of link labels.
53 A link label allows to name a link and associate it to a filter output
54 or input pad. The preceding labels @var{in_link_1}
55 ... @var{in_link_N}, are associated to the filter input pads,
56 the following labels @var{out_link_1} ... @var{out_link_M}, are
57 associated to the output pads.
59 When two link labels with the same name are found in the
60 filtergraph, a link between the corresponding input and output pad is
63 If an output pad is not labelled, it is linked by default to the first
64 unlabelled input pad of the next filter in the filterchain.
65 For example in the filterchain:
67 nullsrc, split[L1], [L2]overlay, nullsink
69 the split filter instance has two output pads, and the overlay filter
70 instance two input pads. The first output pad of split is labelled
71 "L1", the first input pad of overlay is labelled "L2", and the second
72 output pad of split is linked to the second input pad of overlay,
73 which are both unlabelled.
75 In a complete filterchain all the unlabelled filter input and output
76 pads must be connected. A filtergraph is considered valid if all the
77 filter input and output pads of all the filterchains are connected.
79 Follows a BNF description for the filtergraph syntax:
81 @var{NAME} ::= sequence of alphanumeric characters and '_'
82 @var{LINKLABEL} ::= "[" @var{NAME} "]"
83 @var{LINKLABELS} ::= @var{LINKLABEL} [@var{LINKLABELS}]
84 @var{FILTER_ARGUMENTS} ::= sequence of chars (eventually quoted)
85 @var{FILTER} ::= [@var{LINKNAMES}] @var{NAME} ["=" @var{ARGUMENTS}] [@var{LINKNAMES}]
86 @var{FILTERCHAIN} ::= @var{FILTER} [,@var{FILTERCHAIN}]
87 @var{FILTERGRAPH} ::= @var{FILTERCHAIN} [;@var{FILTERGRAPH}]
90 @c man end FILTERGRAPH DESCRIPTION
92 @chapter Audio Filters
93 @c man begin AUDIO FILTERS
95 When you configure your FFmpeg build, you can disable any of the
96 existing filters using --disable-filters.
97 The configure output will show the audio filters included in your
100 Below is a description of the currently available audio filters.
104 Convert the input audio format to the specified formats.
106 The filter accepts a string of the form:
107 "@var{sample_format}:@var{channel_layout}:@var{packing_format}".
109 @var{sample_format} specifies the sample format, and can be a string or
110 the corresponding numeric value defined in @file{libavutil/samplefmt.h}.
112 @var{channel_layout} specifies the channel layout, and can be a string
113 or the corresponding numer value defined in @file{libavutil/chlayout.h}.
115 @var{packing_format} specifies the type of packing in output, can be one
116 of "planar" or "packed", or the corresponding numeric values "0" or "1".
118 The special parameter "auto", signifies that the filter will
119 automatically select the output format depending on the output filter.
121 Some examples follow.
125 Convert input to unsigned 8-bit, stereo, packed:
127 aconvert=u8:stereo:packed
131 Convert input to unsigned 8-bit, automatically select out channel layout
134 aconvert=u8:auto:auto
140 Convert the input audio to one of the specified formats. The framework will
141 negotiate the most appropriate format to minimize conversions.
143 The filter accepts three lists of formats, separated by ":", in the form:
144 "@var{sample_formats}:@var{channel_layouts}:@var{packing_formats}".
146 Elements in each list are separated by "," which has to be escaped in the
147 filtergraph specification.
149 The special parameter "all", in place of a list of elements, signifies all
152 Some examples follow:
154 aformat=u8\\,s16:mono:packed
156 aformat=s16:mono\\,stereo:all
161 Pass the audio source unchanged to the output.
165 Resample the input audio to the specified sample rate.
167 The filter accepts exactly one parameter, the output sample rate. If not
168 specified then the filter will automatically convert between its input
169 and output sample rates.
171 For example, to resample the input audio to 44100Hz:
178 Show a line containing various information for each input audio frame.
179 The input audio is not modified.
181 The shown line contains a sequence of key/value pairs of the form
182 @var{key}:@var{value}.
184 A description of each shown parameter follows:
188 sequential number of the input frame, starting from 0
191 presentation TimeStamp of the input frame, expressed as a number of
192 time base units. The time base unit depends on the filter input pad, and
193 is usually 1/@var{sample_rate}.
196 presentation TimeStamp of the input frame, expressed as a number of
200 position of the frame in the input stream, -1 if this information in
201 unavailable and/or meanigless (for example in case of synthetic audio)
207 channel layout description
210 number of samples (per each channel) contained in the filtered frame
213 sample rate for the audio frame
216 if the packing format is planar, 0 if packed
219 Adler-32 checksum of all the planes of the input frame
222 Adler-32 checksum for each input frame plane, expressed in the form
223 "[@var{c0} @var{c1} @var{c2} @var{c3} @var{c4} @var{c5} @var{c6} @var{c7}]"
226 @c man end AUDIO FILTERS
228 @chapter Audio Sources
229 @c man begin AUDIO SOURCES
231 Below is a description of the currently available audio sources.
235 Buffer audio frames, and make them available to the filter chain.
237 This source is mainly intended for a programmatic use, in particular
238 through the interface defined in @file{libavfilter/asrc_abuffer.h}.
240 It accepts the following mandatory parameters:
241 @var{sample_rate}:@var{sample_fmt}:@var{channel_layout}:@var{packing}
246 The sample rate of the incoming audio buffers.
249 The sample format of the incoming audio buffers.
250 Either a sample format name or its corresponging integer representation from
251 the enum AVSampleFormat in @file{libavutil/samplefmt.h}
254 The channel layout of the incoming audio buffers.
255 Either a channel layout name from channel_layout_map in
256 @file{libavutil/audioconvert.c} or its corresponding integer representation
257 from the AV_CH_LAYOUT_* macros in @file{libavutil/audioconvert.h}
260 Either "packed" or "planar", or their integer representation: 0 or 1
267 abuffer=44100:s16:stereo:planar
270 will instruct the source to accept planar 16bit signed stereo at 44100Hz.
271 Since the sample format with name "s16" corresponds to the number
272 1 and the "stereo" channel layout corresponds to the value 3, this is
280 Read an audio stream from a movie container.
282 It accepts the syntax: @var{movie_name}[:@var{options}] where
283 @var{movie_name} is the name of the resource to read (not necessarily
284 a file but also a device or a stream accessed through some protocol),
285 and @var{options} is an optional sequence of @var{key}=@var{value}
286 pairs, separated by ":".
288 The description of the accepted options follows.
293 Specify the format assumed for the movie to read, and can be either
294 the name of a container or an input device. If not specified the
295 format is guessed from @var{movie_name} or by probing.
298 Specify the seek point in seconds, the frames will be output
299 starting from this seek point, the parameter is evaluated with
300 @code{av_strtod} so the numerical value may be suffixed by an IS
301 postfix. Default value is "0".
303 @item stream_index, si
304 Specify the index of the audio stream to read. If the value is -1,
305 the best suited audio stream will be automatically selected. Default
312 Null audio source, never return audio frames. It is mainly useful as a
313 template and to be employed in analysis / debugging tools.
315 It accepts as optional parameter a string of the form
316 @var{sample_rate}:@var{channel_layout}.
318 @var{sample_rate} specify the sample rate, and defaults to 44100.
320 @var{channel_layout} specify the channel layout, and can be either an
321 integer or a string representing a channel layout. The default value
322 of @var{channel_layout} is 3, which corresponds to CH_LAYOUT_STEREO.
324 Check the channel_layout_map definition in
325 @file{libavcodec/audioconvert.c} for the mapping between strings and
326 channel layout values.
328 Follow some examples:
330 # set the sample rate to 48000 Hz and the channel layout to CH_LAYOUT_MONO.
337 @c man end AUDIO SOURCES
340 @c man begin AUDIO SINKS
342 Below is a description of the currently available audio sinks.
346 Buffer audio frames, and make them available to the end of filter chain.
348 This sink is mainly intended for programmatic use, in particular
349 through the interface defined in @file{libavfilter/buffersink.h}.
351 It requires a pointer to an AVABufferSinkContext structure, which
352 defines the incoming buffers' formats, to be passed as the opaque
353 parameter to @code{avfilter_init_filter} for initialization.
357 Null audio sink, do absolutely nothing with the input audio. It is
358 mainly useful as a template and to be employed in analysis / debugging
361 @c man end AUDIO SINKS
363 @chapter Video Filters
364 @c man begin VIDEO FILTERS
366 When you configure your FFmpeg build, you can disable any of the
367 existing filters using --disable-filters.
368 The configure output will show the video filters included in your
371 Below is a description of the currently available video filters.
375 Detect frames that are (almost) completely black. Can be useful to
376 detect chapter transitions or commercials. Output lines consist of
377 the frame number of the detected frame, the percentage of blackness,
378 the position in the file if known or -1 and the timestamp in seconds.
380 In order to display the output lines, you need to set the loglevel at
381 least to the AV_LOG_INFO value.
383 The filter accepts the syntax:
385 blackframe[=@var{amount}:[@var{threshold}]]
388 @var{amount} is the percentage of the pixels that have to be below the
389 threshold, and defaults to 98.
391 @var{threshold} is the threshold below which a pixel value is
392 considered black, and defaults to 32.
396 Apply boxblur algorithm to the input video.
398 This filter accepts the parameters:
399 @var{luma_radius}:@var{luma_power}:@var{chroma_radius}:@var{chroma_power}:@var{alpha_radius}:@var{alpha_power}
401 Chroma and alpha parameters are optional, if not specified they default
402 to the corresponding values set for @var{luma_radius} and
405 @var{luma_radius}, @var{chroma_radius}, and @var{alpha_radius} represent
406 the radius in pixels of the box used for blurring the corresponding
407 input plane. They are expressions, and can contain the following
411 the input width and heigth in pixels
414 the input chroma image width and height in pixels
417 horizontal and vertical chroma subsample values. For example for the
418 pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
421 The radius must be a non-negative number, and must be not greater than
422 the value of the expression @code{min(w,h)/2} for the luma and alpha planes,
423 and of @code{min(cw,ch)/2} for the chroma planes.
425 @var{luma_power}, @var{chroma_power}, and @var{alpha_power} represent
426 how many times the boxblur filter is applied to the corresponding
429 Some examples follow:
434 Apply a boxblur filter with luma, chroma, and alpha radius
441 Set luma radius to 2, alpha and chroma radius to 0
447 Set luma and chroma radius to a fraction of the video dimension
449 boxblur=min(h\,w)/10:1:min(cw\,ch)/10:1
456 Copy the input source unchanged to the output. Mainly useful for
461 Crop the input video to @var{out_w}:@var{out_h}:@var{x}:@var{y}.
463 The parameters are expressions containing the following constants:
467 the corresponding mathematical approximated values for e
468 (euler number), pi (greek PI), PHI (golden ratio)
471 the computed values for @var{x} and @var{y}. They are evaluated for
475 the input width and heigth
478 same as @var{in_w} and @var{in_h}
481 the output (cropped) width and heigth
484 same as @var{out_w} and @var{out_h}
487 same as @var{iw} / @var{ih}
490 input sample aspect ratio
493 input display aspect ratio, it is the same as (@var{iw} / @var{ih}) * @var{sar}
496 horizontal and vertical chroma subsample values. For example for the
497 pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
500 the number of input frame, starting from 0
503 the position in the file of the input frame, NAN if unknown
506 timestamp expressed in seconds, NAN if the input timestamp is unknown
510 The @var{out_w} and @var{out_h} parameters specify the expressions for
511 the width and height of the output (cropped) video. They are
512 evaluated just at the configuration of the filter.
514 The default value of @var{out_w} is "in_w", and the default value of
515 @var{out_h} is "in_h".
517 The expression for @var{out_w} may depend on the value of @var{out_h},
518 and the expression for @var{out_h} may depend on @var{out_w}, but they
519 cannot depend on @var{x} and @var{y}, as @var{x} and @var{y} are
520 evaluated after @var{out_w} and @var{out_h}.
522 The @var{x} and @var{y} parameters specify the expressions for the
523 position of the top-left corner of the output (non-cropped) area. They
524 are evaluated for each frame. If the evaluated value is not valid, it
525 is approximated to the nearest valid value.
527 The default value of @var{x} is "(in_w-out_w)/2", and the default
528 value for @var{y} is "(in_h-out_h)/2", which set the cropped area at
529 the center of the input image.
531 The expression for @var{x} may depend on @var{y}, and the expression
532 for @var{y} may depend on @var{x}.
534 Follow some examples:
536 # crop the central input area with size 100x100
539 # crop the central input area with size 2/3 of the input video
540 "crop=2/3*in_w:2/3*in_h"
542 # crop the input video central square
545 # delimit the rectangle with the top-left corner placed at position
546 # 100:100 and the right-bottom corner corresponding to the right-bottom
547 # corner of the input image.
548 crop=in_w-100:in_h-100:100:100
550 # crop 10 pixels from the left and right borders, and 20 pixels from
551 # the top and bottom borders
552 "crop=in_w-2*10:in_h-2*20"
554 # keep only the bottom right quarter of the input image
555 "crop=in_w/2:in_h/2:in_w/2:in_h/2"
557 # crop height for getting Greek harmony
558 "crop=in_w:1/PHI*in_w"
561 "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)"
563 # erratic camera effect depending on timestamp
564 "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)"
566 # set x depending on the value of y
567 "crop=in_w/2:in_h/2:y:10+10*sin(n/10)"
572 Auto-detect crop size.
574 Calculate necessary cropping parameters and prints the recommended
575 parameters through the logging system. The detected dimensions
576 correspond to the non-black area of the input video.
578 It accepts the syntax:
580 cropdetect[=@var{limit}[:@var{round}[:@var{reset}]]]
586 Threshold, which can be optionally specified from nothing (0) to
587 everything (255), defaults to 24.
590 Value which the width/height should be divisible by, defaults to
591 16. The offset is automatically adjusted to center the video. Use 2 to
592 get only even dimensions (needed for 4:2:2 video). 16 is best when
593 encoding to most video codecs.
596 Counter that determines after how many frames cropdetect will reset
597 the previously detected largest video area and start over to detect
598 the current optimal crop area. Defaults to 0.
600 This can be useful when channel logos distort the video area. 0
601 indicates never reset and return the largest area encountered during
607 Suppress a TV station logo by a simple interpolation of the surrounding
608 pixels. Just set a rectangle covering the logo and watch it disappear
609 (and sometimes something even uglier appear - your mileage may vary).
611 The filter accepts parameters as a string of the form
612 "@var{x}:@var{y}:@var{w}:@var{h}:@var{band}", or as a list of
613 @var{key}=@var{value} pairs, separated by ":".
615 The description of the accepted parameters follows.
620 Specify the top left corner coordinates of the logo. They must be
624 Specify the width and height of the logo to clear. They must be
628 Specify the thickness of the fuzzy edge of the rectangle (added to
629 @var{w} and @var{h}). The default value is 4.
632 When set to 1, a green rectangle is drawn on the screen to simplify
633 finding the right @var{x}, @var{y}, @var{w}, @var{h} parameters, and
634 @var{band} is set to 4. The default value is 0.
638 Some examples follow.
643 Set a rectangle covering the area with top left corner coordinates 0,0
644 and size 100x77, setting a band of size 10:
650 As the previous example, but use named options:
652 delogo=x=0:y=0:w=100:h=77:band=10
659 Draw a colored box on the input image.
661 It accepts the syntax:
663 drawbox=@var{x}:@var{y}:@var{width}:@var{height}:@var{color}
669 Specify the top left corner coordinates of the box. Default to 0.
672 Specify the width and height of the box, if 0 they are interpreted as
673 the input width and height. Default to 0.
676 Specify the color of the box to write, it can be the name of a color
677 (case insensitive match) or a 0xRRGGBB[AA] sequence.
680 Follow some examples:
682 # draw a black box around the edge of the input image
685 # draw a box with color red and an opacity of 50%
686 drawbox=10:20:200:60:red@@0.5"
691 Draw text string or text from specified file on top of video using the
694 To enable compilation of this filter you need to configure FFmpeg with
695 @code{--enable-libfreetype}.
697 The filter also recognizes strftime() sequences in the provided text
698 and expands them accordingly. Check the documentation of strftime().
700 The filter accepts parameters as a list of @var{key}=@var{value} pairs,
703 The description of the accepted parameters follows.
708 The font file to be used for drawing text. Path must be included.
709 This parameter is mandatory.
712 The text string to be drawn. The text must be a sequence of UTF-8
714 This parameter is mandatory if no file is specified with the parameter
718 A text file containing text to be drawn. The text must be a sequence
719 of UTF-8 encoded characters.
721 This parameter is mandatory if no text string is specified with the
722 parameter @var{text}.
724 If both text and textfile are specified, an error is thrown.
727 The offsets where text will be drawn within the video frame.
728 Relative to the top/left border of the output image.
730 The default value of @var{x} and @var{y} is 0.
733 The font size to be used for drawing text.
734 The default value of @var{fontsize} is 16.
737 The color to be used for drawing fonts.
738 Either a string (e.g. "red") or in 0xRRGGBB[AA] format
739 (e.g. "0xff000033"), possibly followed by an alpha specifier.
740 The default value of @var{fontcolor} is "black".
743 The color to be used for drawing box around text.
744 Either a string (e.g. "yellow") or in 0xRRGGBB[AA] format
745 (e.g. "0xff00ff"), possibly followed by an alpha specifier.
746 The default value of @var{boxcolor} is "white".
749 Used to draw a box around text using background color.
750 Value should be either 1 (enable) or 0 (disable).
751 The default value of @var{box} is 0.
753 @item shadowx, shadowy
754 The x and y offsets for the text shadow position with respect to the
755 position of the text. They can be either positive or negative
756 values. Default value for both is "0".
759 The color to be used for drawing a shadow behind the drawn text. It
760 can be a color name (e.g. "yellow") or a string in the 0xRRGGBB[AA]
761 form (e.g. "0xff00ff"), possibly followed by an alpha specifier.
762 The default value of @var{shadowcolor} is "black".
765 Flags to be used for loading the fonts.
767 The flags map the corresponding flags supported by libfreetype, and are
768 a combination of the following values:
775 @item vertical_layout
779 @item ignore_global_advance_width
781 @item ignore_transform
788 Default value is "render".
790 For more information consult the documentation for the FT_LOAD_*
794 The size in number of spaces to use for rendering the tab.
798 For example the command:
800 drawtext="fontfile=/usr/share/fonts/truetype/freefont/FreeSerif.ttf: text='Test Text'"
803 will draw "Test Text" with font FreeSerif, using the default values
804 for the optional parameters.
808 drawtext="fontfile=/usr/share/fonts/truetype/freefont/FreeSerif.ttf: text='Test Text':\
809 x=100: y=50: fontsize=24: fontcolor=yellow@@0.2: box=1: boxcolor=red@@0.2"
812 will draw 'Test Text' with font FreeSerif of size 24 at position x=100
813 and y=50 (counting from the top-left corner of the screen), text is
814 yellow with a red box around it. Both the text and the box have an
817 Note that the double quotes are not necessary if spaces are not used
818 within the parameter list.
820 For more information about libfreetype, check:
821 @url{http://www.freetype.org/}.
825 Apply fade-in/out effect to input video.
827 It accepts the parameters:
828 @var{type}:@var{start_frame}:@var{nb_frames}
830 @var{type} specifies if the effect type, can be either "in" for
831 fade-in, or "out" for a fade-out effect.
833 @var{start_frame} specifies the number of the start frame for starting
834 to apply the fade effect.
836 @var{nb_frames} specifies the number of frames for which the fade
837 effect has to last. At the end of the fade-in effect the output video
838 will have the same intensity as the input video, at the end of the
839 fade-out transition the output video will be completely black.
841 A few usage examples follow, usable too as test scenarios.
843 # fade in first 30 frames of video
846 # fade out last 45 frames of a 200-frame video
849 # fade in first 25 frames and fade out last 25 frames of a 1000-frame video
850 fade=in:0:25, fade=out:975:25
852 # make first 5 frames black, then fade in from frame 5-24
858 Transform the field order of the input video.
860 It accepts one parameter which specifies the required field order that
861 the input interlaced video will be transformed to. The parameter can
862 assume one of the following values:
866 output bottom field first
868 output top field first
871 Default value is "tff".
873 Transformation is achieved by shifting the picture content up or down
874 by one line, and filling the remaining line with appropriate picture content.
875 This method is consistent with most broadcast field order converters.
877 If the input video is not flagged as being interlaced, or it is already
878 flagged as being of the required output field order then this filter does
879 not alter the incoming video.
881 This filter is very useful when converting to or from PAL DV material,
882 which is bottom field first.
886 ./ffmpeg -i in.vob -vf "fieldorder=bff" out.dv
891 Buffer input images and send them when they are requested.
893 This filter is mainly useful when auto-inserted by the libavfilter
896 The filter does not take parameters.
900 Convert the input video to one of the specified pixel formats.
901 Libavfilter will try to pick one that is supported for the input to
904 The filter accepts a list of pixel format names, separated by ":",
905 for example "yuv420p:monow:rgb24".
907 Some examples follow:
909 # convert the input video to the format "yuv420p"
912 # convert the input video to any of the formats in the list
913 format=yuv420p:yuv444p:yuv410p
919 Apply a frei0r effect to the input video.
921 To enable compilation of this filter you need to install the frei0r
922 header and configure FFmpeg with --enable-frei0r.
924 The filter supports the syntax:
926 @var{filter_name}[@{:|=@}@var{param1}:@var{param2}:...:@var{paramN}]
929 @var{filter_name} is the name to the frei0r effect to load. If the
930 environment variable @env{FREI0R_PATH} is defined, the frei0r effect
931 is searched in each one of the directories specified by the colon
932 separated list in @env{FREIOR_PATH}, otherwise in the standard frei0r
933 paths, which are in this order: @file{HOME/.frei0r-1/lib/},
934 @file{/usr/local/lib/frei0r-1/}, @file{/usr/lib/frei0r-1/}.
936 @var{param1}, @var{param2}, ... , @var{paramN} specify the parameters
937 for the frei0r effect.
939 A frei0r effect parameter can be a boolean (whose values are specified
940 with "y" and "n"), a double, a color (specified by the syntax
941 @var{R}/@var{G}/@var{B}, @var{R}, @var{G}, and @var{B} being float
942 numbers from 0.0 to 1.0) or by an @code{av_parse_color()} color
943 description), a position (specified by the syntax @var{X}/@var{Y},
944 @var{X} and @var{Y} being float numbers) and a string.
946 The number and kind of parameters depend on the loaded effect. If an
947 effect parameter is not specified the default value is set.
949 Some examples follow:
951 # apply the distort0r effect, set the first two double parameters
952 frei0r=distort0r:0.5:0.01
954 # apply the colordistance effect, takes a color as first parameter
955 frei0r=colordistance:0.2/0.3/0.4
956 frei0r=colordistance:violet
957 frei0r=colordistance:0x112233
959 # apply the perspective effect, specify the top left and top right
961 frei0r=perspective:0.2/0.2:0.8/0.2
964 For more information see:
965 @url{http://piksel.org/frei0r}
969 Fix the banding artifacts that are sometimes introduced into nearly flat
970 regions by truncation to 8bit colordepth.
971 Interpolate the gradients that should go where the bands are, and
974 This filter is designed for playback only. Do not use it prior to
975 lossy compression, because compression tends to lose the dither and
976 bring back the bands.
978 The filter takes two optional parameters, separated by ':':
979 @var{strength}:@var{radius}
981 @var{strength} is the maximum amount by which the filter will change
982 any one pixel. Also the threshold for detecting nearly flat
983 regions. Acceptable values range from .51 to 255, default value is
984 1.2, out-of-range values will be clipped to the valid range.
986 @var{radius} is the neighborhood to fit the gradient to. A larger
987 radius makes for smoother gradients, but also prevents the filter from
988 modifying the pixels near detailed regions. Acceptable values are
989 8-32, default value is 16, out-of-range values will be clipped to the
1002 Flip the input video horizontally.
1004 For example to horizontally flip the video in input with
1007 ffmpeg -i in.avi -vf "hflip" out.avi
1012 High precision/quality 3d denoise filter. This filter aims to reduce
1013 image noise producing smooth images and making still images really
1014 still. It should enhance compressibility.
1016 It accepts the following optional parameters:
1017 @var{luma_spatial}:@var{chroma_spatial}:@var{luma_tmp}:@var{chroma_tmp}
1021 a non-negative float number which specifies spatial luma strength,
1024 @item chroma_spatial
1025 a non-negative float number which specifies spatial chroma strength,
1026 defaults to 3.0*@var{luma_spatial}/4.0
1029 a float number which specifies luma temporal strength, defaults to
1030 6.0*@var{luma_spatial}/4.0
1033 a float number which specifies chroma temporal strength, defaults to
1034 @var{luma_tmp}*@var{chroma_spatial}/@var{luma_spatial}
1037 @section lut, lutrgb, lutyuv
1039 Compute a look-up table for binding each pixel component input value
1040 to an output value, and apply it to input video.
1042 @var{lutyuv} applies a lookup table to a YUV input video, @var{lutrgb}
1043 to an RGB input video.
1045 These filters accept in input a ":"-separated list of options, which
1046 specify the expressions used for computing the lookup table for the
1047 corresponding pixel component values.
1049 The @var{lut} filter requires either YUV or RGB pixel formats in
1050 input, and accepts the options:
1052 @var{c0} (first pixel component)
1053 @var{c1} (second pixel component)
1054 @var{c2} (third pixel component)
1055 @var{c3} (fourth pixel component, corresponds to the alpha component)
1058 The exact component associated to each option depends on the format in
1061 The @var{lutrgb} filter requires RGB pixel formats in input, and
1062 accepts the options:
1064 @var{r} (red component)
1065 @var{g} (green component)
1066 @var{b} (blue component)
1067 @var{a} (alpha component)
1070 The @var{lutyuv} filter requires YUV pixel formats in input, and
1071 accepts the options:
1073 @var{y} (Y/luminance component)
1074 @var{u} (U/Cb component)
1075 @var{v} (V/Cr component)
1076 @var{a} (alpha component)
1079 The expressions can contain the following constants and functions:
1083 the corresponding mathematical approximated values for e
1084 (euler number), pi (greek PI), PHI (golden ratio)
1087 the input width and heigth
1090 input value for the pixel component
1093 the input value clipped in the @var{minval}-@var{maxval} range
1096 maximum value for the pixel component
1099 minimum value for the pixel component
1102 the negated value for the pixel component value clipped in the
1103 @var{minval}-@var{maxval} range , it corresponds to the expression
1104 "maxval-clipval+minval"
1107 the computed value in @var{val} clipped in the
1108 @var{minval}-@var{maxval} range
1110 @item gammaval(gamma)
1111 the computed gamma correction value of the pixel component value
1112 clipped in the @var{minval}-@var{maxval} range, corresponds to the
1114 "pow((clipval-minval)/(maxval-minval)\,@var{gamma})*(maxval-minval)+minval"
1118 All expressions default to "val".
1120 Some examples follow:
1122 # negate input video
1123 lutrgb="r=maxval+minval-val:g=maxval+minval-val:b=maxval+minval-val"
1124 lutyuv="y=maxval+minval-val:u=maxval+minval-val:v=maxval+minval-val"
1126 # the above is the same as
1127 lutrgb="r=negval:g=negval:b=negval"
1128 lutyuv="y=negval:u=negval:v=negval"
1133 # remove chroma components, turns the video into a graytone image
1134 lutyuv="u=128:v=128"
1136 # apply a luma burning effect
1139 # remove green and blue components
1142 # set a constant alpha channel value on input
1143 format=rgba,lutrgb=a="maxval-minval/2"
1145 # correct luminance gamma by a 0.5 factor
1146 lutyuv=y=gammaval(0.5)
1151 Apply an MPlayer filter to the input video.
1153 This filter provides a wrapper around most of the filters of
1156 This wrapper is considered experimental. Some of the wrapped filters
1157 may not work properly and we may drop support for them, as they will
1158 be implemented natively into FFmpeg. Thus you should avoid
1159 depending on them when writing portable scripts.
1161 The filters accepts the parameters:
1162 @var{filter_name}[:=]@var{filter_params}
1164 @var{filter_name} is the name of a supported MPlayer filter,
1165 @var{filter_params} is a string containing the parameters accepted by
1168 The list of the currently supported filters follows:
1222 The parameter syntax and behavior for the listed filters are the same
1223 of the corresponding MPlayer filters. For detailed instructions check
1224 the "VIDEO FILTERS" section in the MPlayer manual.
1226 Some examples follow:
1228 # remove a logo by interpolating the surrounding pixels
1229 mp=delogo=200:200:80:20:1
1231 # adjust gamma, brightness, contrast
1234 # tweak hue and saturation
1238 See also mplayer(1), @url{http://www.mplayerhq.hu/}.
1244 This filter accepts an integer in input, if non-zero it negates the
1245 alpha component (if available). The default value in input is 0.
1249 Force libavfilter not to use any of the specified pixel formats for the
1250 input to the next filter.
1252 The filter accepts a list of pixel format names, separated by ":",
1253 for example "yuv420p:monow:rgb24".
1255 Some examples follow:
1257 # force libavfilter to use a format different from "yuv420p" for the
1258 # input to the vflip filter
1259 noformat=yuv420p,vflip
1261 # convert the input video to any of the formats not contained in the list
1262 noformat=yuv420p:yuv444p:yuv410p
1267 Pass the video source unchanged to the output.
1271 Apply video transform using libopencv.
1273 To enable this filter install libopencv library and headers and
1274 configure FFmpeg with --enable-libopencv.
1276 The filter takes the parameters: @var{filter_name}@{:=@}@var{filter_params}.
1278 @var{filter_name} is the name of the libopencv filter to apply.
1280 @var{filter_params} specifies the parameters to pass to the libopencv
1281 filter. If not specified the default values are assumed.
1283 Refer to the official libopencv documentation for more precise
1285 @url{http://opencv.willowgarage.com/documentation/c/image_filtering.html}
1287 Follows the list of supported libopencv filters.
1292 Dilate an image by using a specific structuring element.
1293 This filter corresponds to the libopencv function @code{cvDilate}.
1295 It accepts the parameters: @var{struct_el}:@var{nb_iterations}.
1297 @var{struct_el} represents a structuring element, and has the syntax:
1298 @var{cols}x@var{rows}+@var{anchor_x}x@var{anchor_y}/@var{shape}
1300 @var{cols} and @var{rows} represent the number of colums and rows of
1301 the structuring element, @var{anchor_x} and @var{anchor_y} the anchor
1302 point, and @var{shape} the shape for the structuring element, and
1303 can be one of the values "rect", "cross", "ellipse", "custom".
1305 If the value for @var{shape} is "custom", it must be followed by a
1306 string of the form "=@var{filename}". The file with name
1307 @var{filename} is assumed to represent a binary image, with each
1308 printable character corresponding to a bright pixel. When a custom
1309 @var{shape} is used, @var{cols} and @var{rows} are ignored, the number
1310 or columns and rows of the read file are assumed instead.
1312 The default value for @var{struct_el} is "3x3+0x0/rect".
1314 @var{nb_iterations} specifies the number of times the transform is
1315 applied to the image, and defaults to 1.
1317 Follow some example:
1319 # use the default values
1322 # dilate using a structuring element with a 5x5 cross, iterate two times
1323 ocv=dilate=5x5+2x2/cross:2
1325 # read the shape from the file diamond.shape, iterate two times
1326 # the file diamond.shape may contain a pattern of characters like this:
1332 # the specified cols and rows are ignored (but not the anchor point coordinates)
1333 ocv=0x0+2x2/custom=diamond.shape:2
1338 Erode an image by using a specific structuring element.
1339 This filter corresponds to the libopencv function @code{cvErode}.
1341 The filter accepts the parameters: @var{struct_el}:@var{nb_iterations},
1342 with the same syntax and semantics as the @ref{dilate} filter.
1346 Smooth the input video.
1348 The filter takes the following parameters:
1349 @var{type}:@var{param1}:@var{param2}:@var{param3}:@var{param4}.
1351 @var{type} is the type of smooth filter to apply, and can be one of
1352 the following values: "blur", "blur_no_scale", "median", "gaussian",
1353 "bilateral". The default value is "gaussian".
1355 @var{param1}, @var{param2}, @var{param3}, and @var{param4} are
1356 parameters whose meanings depend on smooth type. @var{param1} and
1357 @var{param2} accept integer positive values or 0, @var{param3} and
1358 @var{param4} accept float values.
1360 The default value for @var{param1} is 3, the default value for the
1361 other parameters is 0.
1363 These parameters correspond to the parameters assigned to the
1364 libopencv function @code{cvSmooth}.
1368 Overlay one video on top of another.
1370 It takes two inputs and one output, the first input is the "main"
1371 video on which the second input is overlayed.
1373 It accepts the parameters: @var{x}:@var{y}.
1375 @var{x} is the x coordinate of the overlayed video on the main video,
1376 @var{y} is the y coordinate. The parameters are expressions containing
1377 the following parameters:
1380 @item main_w, main_h
1381 main input width and height
1384 same as @var{main_w} and @var{main_h}
1386 @item overlay_w, overlay_h
1387 overlay input width and height
1390 same as @var{overlay_w} and @var{overlay_h}
1393 Be aware that frames are taken from each input video in timestamp
1394 order, hence, if their initial timestamps differ, it is a a good idea
1395 to pass the two inputs through a @var{setpts=PTS-STARTPTS} filter to
1396 have them begin in the same zero timestamp, as it does the example for
1397 the @var{movie} filter.
1399 Follow some examples:
1401 # draw the overlay at 10 pixels from the bottom right
1402 # corner of the main video.
1403 overlay=main_w-overlay_w-10:main_h-overlay_h-10
1405 # insert a transparent PNG logo in the bottom left corner of the input
1406 movie=logo.png [logo];
1407 [in][logo] overlay=10:main_h-overlay_h-10 [out]
1409 # insert 2 different transparent PNG logos (second logo on bottom
1411 movie=logo1.png [logo1];
1412 movie=logo2.png [logo2];
1413 [in][logo1] overlay=10:H-h-10 [in+logo1];
1414 [in+logo1][logo2] overlay=W-w-10:H-h-10 [out]
1416 # add a transparent color layer on top of the main video,
1417 # WxH specifies the size of the main input to the overlay filter
1418 color=red@.3:WxH [over]; [in][over] overlay [out]
1421 You can chain togheter more overlays but the efficiency of such
1422 approach is yet to be tested.
1426 Add paddings to the input image, and places the original input at the
1427 given coordinates @var{x}, @var{y}.
1429 It accepts the following parameters:
1430 @var{width}:@var{height}:@var{x}:@var{y}:@var{color}.
1432 The parameters @var{width}, @var{height}, @var{x}, and @var{y} are
1433 expressions containing the following constants:
1437 the corresponding mathematical approximated values for e
1438 (euler number), pi (greek PI), phi (golden ratio)
1441 the input video width and heigth
1444 same as @var{in_w} and @var{in_h}
1447 the output width and heigth, that is the size of the padded area as
1448 specified by the @var{width} and @var{height} expressions
1451 same as @var{out_w} and @var{out_h}
1454 x and y offsets as specified by the @var{x} and @var{y}
1455 expressions, or NAN if not yet specified
1458 same as @var{iw} / @var{ih}
1461 input sample aspect ratio
1464 input display aspect ratio, it is the same as (@var{iw} / @var{ih}) * @var{sar}
1467 horizontal and vertical chroma subsample values. For example for the
1468 pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
1471 Follows the description of the accepted parameters.
1476 Specify the size of the output image with the paddings added. If the
1477 value for @var{width} or @var{height} is 0, the corresponding input size
1478 is used for the output.
1480 The @var{width} expression can reference the value set by the
1481 @var{height} expression, and viceversa.
1483 The default value of @var{width} and @var{height} is 0.
1487 Specify the offsets where to place the input image in the padded area
1488 with respect to the top/left border of the output image.
1490 The @var{x} expression can reference the value set by the @var{y}
1491 expression, and viceversa.
1493 The default value of @var{x} and @var{y} is 0.
1497 Specify the color of the padded area, it can be the name of a color
1498 (case insensitive match) or a 0xRRGGBB[AA] sequence.
1500 The default value of @var{color} is "black".
1504 Some examples follow:
1507 # Add paddings with color "violet" to the input video. Output video
1508 # size is 640x480, the top-left corner of the input video is placed at
1510 pad=640:480:0:40:violet
1512 # pad the input to get an output with dimensions increased bt 3/2,
1513 # and put the input video at the center of the padded area
1514 pad="3/2*iw:3/2*ih:(ow-iw)/2:(oh-ih)/2"
1516 # pad the input to get a squared output with size equal to the maximum
1517 # value between the input width and height, and put the input video at
1518 # the center of the padded area
1519 pad="max(iw\,ih):ow:(ow-iw)/2:(oh-ih)/2"
1521 # pad the input to get a final w/h ratio of 16:9
1522 pad="ih*16/9:ih:(ow-iw)/2:(oh-ih)/2"
1524 # for anamorphic video, in order to set the output display aspect ratio,
1525 # it is necessary to use sar in the expression, according to the relation:
1526 # (ih * X / ih) * sar = output_dar
1527 # X = output_dar / sar
1528 pad="ih*16/9/sar:ih:(ow-iw)/2:(oh-ih)/2"
1530 # double output size and put the input video in the bottom-right
1531 # corner of the output padded area
1532 pad="2*iw:2*ih:ow-iw:oh-ih"
1535 @section pixdesctest
1537 Pixel format descriptor test filter, mainly useful for internal
1538 testing. The output video should be equal to the input video.
1542 format=monow, pixdesctest
1545 can be used to test the monowhite pixel format descriptor definition.
1549 Scale the input video to @var{width}:@var{height} and/or convert the image format.
1551 The parameters @var{width} and @var{height} are expressions containing
1552 the following constants:
1556 the corresponding mathematical approximated values for e
1557 (euler number), pi (greek PI), phi (golden ratio)
1560 the input width and heigth
1563 same as @var{in_w} and @var{in_h}
1566 the output (cropped) width and heigth
1569 same as @var{out_w} and @var{out_h}
1572 same as @var{iw} / @var{ih}
1575 input sample aspect ratio
1578 input display aspect ratio, it is the same as (@var{iw} / @var{ih}) * @var{sar}
1581 horizontal and vertical chroma subsample values. For example for the
1582 pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
1585 If the input image format is different from the format requested by
1586 the next filter, the scale filter will convert the input to the
1589 If the value for @var{width} or @var{height} is 0, the respective input
1590 size is used for the output.
1592 If the value for @var{width} or @var{height} is -1, the scale filter will
1593 use, for the respective output size, a value that maintains the aspect
1594 ratio of the input image.
1596 The default value of @var{width} and @var{height} is 0.
1598 Some examples follow:
1600 # scale the input video to a size of 200x100.
1603 # scale the input to 2x
1605 # the above is the same as
1608 # scale the input to half size
1611 # increase the width, and set the height to the same size
1614 # seek for Greek harmony
1618 # increase the height, and set the width to 3/2 of the height
1621 # increase the size, but make the size a multiple of the chroma
1622 scale="trunc(3/2*iw/hsub)*hsub:trunc(3/2*ih/vsub)*vsub"
1624 # increase the width to a maximum of 500 pixels, keep the same input aspect ratio
1625 scale='min(500\, iw*3/2):-1'
1629 Select frames to pass in output.
1631 It accepts in input an expression, which is evaluated for each input
1632 frame. If the expression is evaluated to a non-zero value, the frame
1633 is selected and passed to the output, otherwise it is discarded.
1635 The expression can contain the following constants:
1648 the sequential number of the filtered frame, starting from 0
1651 the sequential number of the selected frame, starting from 0
1653 @item prev_selected_n
1654 the sequential number of the last selected frame, NAN if undefined
1657 timebase of the input timestamps
1660 the PTS (Presentation TimeStamp) of the filtered video frame,
1661 expressed in @var{TB} units, NAN if undefined
1664 the PTS (Presentation TimeStamp) of the filtered video frame,
1665 expressed in seconds, NAN if undefined
1668 the PTS of the previously filtered video frame, NAN if undefined
1670 @item prev_selected_pts
1671 the PTS of the last previously filtered video frame, NAN if undefined
1673 @item prev_selected_t
1674 the PTS of the last previously selected video frame, NAN if undefined
1677 the PTS of the first video frame in the video, NAN if undefined
1680 the time of the first video frame in the video, NAN if undefined
1683 the picture type of the filtered frame, can assume one of the following
1695 @item interlace_type
1696 the frame interlace type, can assume one of the following values:
1698 @item INTERLACE_TYPE_P
1699 the frame is progressive (not interlaced)
1700 @item INTERLACE_TYPE_T
1701 the frame is top-field-first
1702 @item INTERLACE_TYPE_B
1703 the frame is bottom-field-first
1707 1 if the filtered frame is a key-frame, 0 otherwise
1710 the position in the file of the filtered frame, -1 if the information
1711 is not available (e.g. for synthetic video)
1714 The default value of the select expression is "1".
1716 Some examples follow:
1719 # select all frames in input
1722 # the above is the same as:
1728 # select only I-frames
1729 select='eq(pict_type\,PICT_TYPE_I)'
1731 # select one frame every 100
1732 select='not(mod(n\,100))'
1734 # select only frames contained in the 10-20 time interval
1735 select='gte(t\,10)*lte(t\,20)'
1737 # select only I frames contained in the 10-20 time interval
1738 select='gte(t\,10)*lte(t\,20)*eq(pict_type\,PICT_TYPE_I)'
1740 # select frames with a minimum distance of 10 seconds
1741 select='isnan(prev_selected_t)+gte(t-prev_selected_t\,10)'
1747 Set the Display Aspect Ratio for the filter output video.
1749 This is done by changing the specified Sample (aka Pixel) Aspect
1750 Ratio, according to the following equation:
1751 @math{DAR = HORIZONTAL_RESOLUTION / VERTICAL_RESOLUTION * SAR}
1753 Keep in mind that this filter does not modify the pixel dimensions of
1754 the video frame. Also the display aspect ratio set by this filter may
1755 be changed by later filters in the filterchain, e.g. in case of
1756 scaling or if another "setdar" or a "setsar" filter is applied.
1758 The filter accepts a parameter string which represents the wanted
1759 display aspect ratio.
1760 The parameter can be a floating point number string, or an expression
1761 of the form @var{num}:@var{den}, where @var{num} and @var{den} are the
1762 numerator and denominator of the aspect ratio.
1763 If the parameter is not specified, it is assumed the value "0:1".
1765 For example to change the display aspect ratio to 16:9, specify:
1768 # the above is equivalent to
1772 See also the @ref{setsar} filter documentation.
1776 Change the PTS (presentation timestamp) of the input video frames.
1778 Accept in input an expression evaluated through the eval API, which
1779 can contain the following constants:
1783 the presentation timestamp in input
1795 the count of the input frame, starting from 0.
1798 the PTS of the first video frame
1801 tell if the current frame is interlaced
1804 original position in the file of the frame, or undefined if undefined
1805 for the current frame
1815 Some examples follow:
1818 # start counting PTS from zero
1830 # fixed rate 25 fps with some jitter
1831 setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))'
1837 Set the Sample (aka Pixel) Aspect Ratio for the filter output video.
1839 Note that as a consequence of the application of this filter, the
1840 output display aspect ratio will change according to the following
1842 @math{DAR = HORIZONTAL_RESOLUTION / VERTICAL_RESOLUTION * SAR}
1844 Keep in mind that the sample aspect ratio set by this filter may be
1845 changed by later filters in the filterchain, e.g. if another "setsar"
1846 or a "setdar" filter is applied.
1848 The filter accepts a parameter string which represents the wanted
1849 sample aspect ratio.
1850 The parameter can be a floating point number string, or an expression
1851 of the form @var{num}:@var{den}, where @var{num} and @var{den} are the
1852 numerator and denominator of the aspect ratio.
1853 If the parameter is not specified, it is assumed the value "0:1".
1855 For example to change the sample aspect ratio to 10:11, specify:
1862 Set the timebase to use for the output frames timestamps.
1863 It is mainly useful for testing timebase configuration.
1865 It accepts in input an arithmetic expression representing a rational.
1866 The expression can contain the constants "PI", "E", "PHI", "AVTB" (the
1867 default timebase), and "intb" (the input timebase).
1869 The default value for the input is "intb".
1871 Follow some examples.
1874 # set the timebase to 1/25
1877 # set the timebase to 1/10
1880 #set the timebase to 1001/1000
1883 #set the timebase to 2*intb
1886 #set the default timebase value
1892 Show a line containing various information for each input video frame.
1893 The input video is not modified.
1895 The shown line contains a sequence of key/value pairs of the form
1896 @var{key}:@var{value}.
1898 A description of each shown parameter follows:
1902 sequential number of the input frame, starting from 0
1905 Presentation TimeStamp of the input frame, expressed as a number of
1906 time base units. The time base unit depends on the filter input pad.
1909 Presentation TimeStamp of the input frame, expressed as a number of
1913 position of the frame in the input stream, -1 if this information in
1914 unavailable and/or meanigless (for example in case of synthetic video)
1920 sample aspect ratio of the input frame, expressed in the form
1924 size of the input frame, expressed in the form
1925 @var{width}x@var{height}
1928 interlaced mode ("P" for "progressive", "T" for top field first, "B"
1929 for bottom field first)
1932 1 if the frame is a key frame, 0 otherwise
1935 picture type of the input frame ("I" for an I-frame, "P" for a
1936 P-frame, "B" for a B-frame, "?" for unknown type).
1937 Check also the documentation of the @code{AVPictureType} enum and of
1938 the @code{av_get_picture_type_char} function defined in
1939 @file{libavutil/avutil.h}.
1942 Adler-32 checksum of all the planes of the input frame
1944 @item plane_checksum
1945 Adler-32 checksum of each plane of the input frame, expressed in the form
1946 "[@var{c0} @var{c1} @var{c2} @var{c3}]"
1951 Pass the images of input video on to next video filter as multiple
1955 ./ffmpeg -i in.avi -vf "slicify=32" out.avi
1958 The filter accepts the slice height as parameter. If the parameter is
1959 not specified it will use the default value of 16.
1961 Adding this in the beginning of filter chains should make filtering
1962 faster due to better use of the memory cache.
1966 Pass on the input video to two outputs. Both outputs are identical to
1971 [in] split [splitout1][splitout2];
1972 [splitout1] crop=100:100:0:0 [cropout];
1973 [splitout2] pad=200:200:100:100 [padout];
1976 will create two separate outputs from the same input, one cropped and
1981 Transpose rows with columns in the input video and optionally flip it.
1983 It accepts a parameter representing an integer, which can assume the
1988 Rotate by 90 degrees counterclockwise and vertically flip (default), that is:
1996 Rotate by 90 degrees clockwise, that is:
2004 Rotate by 90 degrees counterclockwise, that is:
2012 Rotate by 90 degrees clockwise and vertically flip, that is:
2022 Sharpen or blur the input video.
2024 It accepts the following parameters:
2025 @var{luma_msize_x}:@var{luma_msize_y}:@var{luma_amount}:@var{chroma_msize_x}:@var{chroma_msize_y}:@var{chroma_amount}
2027 Negative values for the amount will blur the input video, while positive
2028 values will sharpen. All parameters are optional and default to the
2029 equivalent of the string '5:5:1.0:5:5:0.0'.
2034 Set the luma matrix horizontal size. It can be an integer between 3
2035 and 13, default value is 5.
2038 Set the luma matrix vertical size. It can be an integer between 3
2039 and 13, default value is 5.
2042 Set the luma effect strength. It can be a float number between -2.0
2043 and 5.0, default value is 1.0.
2045 @item chroma_msize_x
2046 Set the chroma matrix horizontal size. It can be an integer between 3
2047 and 13, default value is 5.
2049 @item chroma_msize_y
2050 Set the chroma matrix vertical size. It can be an integer between 3
2051 and 13, default value is 5.
2054 Set the chroma effect strength. It can be a float number between -2.0
2055 and 5.0, default value is 0.0.
2060 # Strong luma sharpen effect parameters
2063 # Strong blur of both luma and chroma parameters
2064 unsharp=7:7:-2:7:7:-2
2066 # Use the default values with @command{ffmpeg}
2067 ./ffmpeg -i in.avi -vf "unsharp" out.mp4
2072 Flip the input video vertically.
2075 ./ffmpeg -i in.avi -vf "vflip" out.avi
2080 Deinterlace the input video ("yadif" means "yet another deinterlacing
2083 It accepts the optional parameters: @var{mode}:@var{parity}:@var{auto}.
2085 @var{mode} specifies the interlacing mode to adopt, accepts one of the
2090 output 1 frame for each frame
2092 output 1 frame for each field
2094 like 0 but skips spatial interlacing check
2096 like 1 but skips spatial interlacing check
2101 @var{parity} specifies the picture field parity assumed for the input
2102 interlaced video, accepts one of the following values:
2106 assume top field first
2108 assume bottom field first
2110 enable automatic detection
2113 Default value is -1.
2114 If interlacing is unknown or decoder does not export this information,
2115 top field first will be assumed.
2117 @var{auto} specifies if deinterlacer should trust the interlaced flag
2118 and only deinterlace frames marked as interlaced
2122 deinterlace all frames
2124 only deinterlace frames marked as interlaced
2129 @c man end VIDEO FILTERS
2131 @chapter Video Sources
2132 @c man begin VIDEO SOURCES
2134 Below is a description of the currently available video sources.
2138 Buffer video frames, and make them available to the filter chain.
2140 This source is mainly intended for a programmatic use, in particular
2141 through the interface defined in @file{libavfilter/vsrc_buffer.h}.
2143 It accepts the following parameters:
2144 @var{width}:@var{height}:@var{pix_fmt_string}:@var{timebase_num}:@var{timebase_den}:@var{sample_aspect_ratio_num}:@var{sample_aspect_ratio.den}:@var{scale_params}
2146 All the parameters but @var{scale_params} need to be explicitely
2149 Follows the list of the accepted parameters.
2154 Specify the width and height of the buffered video frames.
2156 @item pix_fmt_string
2157 A string representing the pixel format of the buffered video frames.
2158 It may be a number corresponding to a pixel format, or a pixel format
2161 @item timebase_num, timebase_den
2162 Specify numerator and denomitor of the timebase assumed by the
2163 timestamps of the buffered frames.
2165 @item sample_aspect_ratio.num, sample_aspect_ratio.den
2166 Specify numerator and denominator of the sample aspect ratio assumed
2167 by the video frames.
2170 Specify the optional parameters to be used for the scale filter which
2171 is automatically inserted when an input change is detected in the
2172 input size or format.
2177 buffer=320:240:yuv410p:1:24:1:1
2180 will instruct the source to accept video frames with size 320x240 and
2181 with format "yuv410p", assuming 1/24 as the timestamps timebase and
2182 square pixels (1:1 sample aspect ratio).
2183 Since the pixel format with name "yuv410p" corresponds to the number 6
2184 (check the enum PixelFormat definition in @file{libavutil/pixfmt.h}),
2185 this example corresponds to:
2187 buffer=320:240:6:1:24:1:1
2192 Provide an uniformly colored input.
2194 It accepts the following parameters:
2195 @var{color}:@var{frame_size}:@var{frame_rate}
2197 Follows the description of the accepted parameters.
2202 Specify the color of the source. It can be the name of a color (case
2203 insensitive match) or a 0xRRGGBB[AA] sequence, possibly followed by an
2204 alpha specifier. The default value is "black".
2207 Specify the size of the sourced video, it may be a string of the form
2208 @var{width}x@var{heigth}, or the name of a size abbreviation. The
2209 default value is "320x240".
2212 Specify the frame rate of the sourced video, as the number of frames
2213 generated per second. It has to be a string in the format
2214 @var{frame_rate_num}/@var{frame_rate_den}, an integer number, a float
2215 number or a valid video frame rate abbreviation. The default value is
2220 For example the following graph description will generate a red source
2221 with an opacity of 0.2, with size "qcif" and a frame rate of 10
2222 frames per second, which will be overlayed over the source connected
2223 to the pad with identifier "in".
2226 "color=red@@0.2:qcif:10 [color]; [in][color] overlay [out]"
2231 Read a video stream from a movie container.
2233 It accepts the syntax: @var{movie_name}[:@var{options}] where
2234 @var{movie_name} is the name of the resource to read (not necessarily
2235 a file but also a device or a stream accessed through some protocol),
2236 and @var{options} is an optional sequence of @var{key}=@var{value}
2237 pairs, separated by ":".
2239 The description of the accepted options follows.
2243 @item format_name, f
2244 Specifies the format assumed for the movie to read, and can be either
2245 the name of a container or an input device. If not specified the
2246 format is guessed from @var{movie_name} or by probing.
2248 @item seek_point, sp
2249 Specifies the seek point in seconds, the frames will be output
2250 starting from this seek point, the parameter is evaluated with
2251 @code{av_strtod} so the numerical value may be suffixed by an IS
2252 postfix. Default value is "0".
2254 @item stream_index, si
2255 Specifies the index of the video stream to read. If the value is -1,
2256 the best suited video stream will be automatically selected. Default
2261 This filter allows to overlay a second video on top of main input of
2262 a filtergraph as shown in this graph:
2264 input -----------> deltapts0 --> overlay --> output
2267 movie --> scale--> deltapts1 -------+
2270 Some examples follow:
2272 # skip 3.2 seconds from the start of the avi file in.avi, and overlay it
2273 # on top of the input labelled as "in".
2274 movie=in.avi:seek_point=3.2, scale=180:-1, setpts=PTS-STARTPTS [movie];
2275 [in] setpts=PTS-STARTPTS, [movie] overlay=16:16 [out]
2277 # read from a video4linux2 device, and overlay it on top of the input
2279 movie=/dev/video0:f=video4linux2, scale=180:-1, setpts=PTS-STARTPTS [movie];
2280 [in] setpts=PTS-STARTPTS, [movie] overlay=16:16 [out]
2286 Generate various test patterns, as generated by the MPlayer test filter.
2288 The size of the generated video is fixed, and is 256x256.
2289 This source is useful in particular for testing encoding features.
2291 This source accepts an optional sequence of @var{key}=@var{value} pairs,
2292 separated by ":". The description of the accepted options follows.
2297 Specify the frame rate of the sourced video, as the number of frames
2298 generated per second. It has to be a string in the format
2299 @var{frame_rate_num}/@var{frame_rate_den}, an integer number, a float
2300 number or a valid video frame rate abbreviation. The default value is
2304 Set the video duration of the sourced video. The accepted syntax is:
2306 [-]HH[:MM[:SS[.m...]]]
2309 See also the function @code{av_parse_time()}.
2311 If not specified, or the expressed duration is negative, the video is
2312 supposed to be generated forever.
2316 Set the number or the name of the test to perform. Supported tests are:
2331 Default value is "all", which will cycle through the list of all tests.
2334 For example the following:
2339 will generate a "dc_luma" test pattern.
2343 Null video source, never return images. It is mainly useful as a
2344 template and to be employed in analysis / debugging tools.
2346 It accepts as optional parameter a string of the form
2347 @var{width}:@var{height}:@var{timebase}.
2349 @var{width} and @var{height} specify the size of the configured
2350 source. The default values of @var{width} and @var{height} are
2351 respectively 352 and 288 (corresponding to the CIF size format).
2353 @var{timebase} specifies an arithmetic expression representing a
2354 timebase. The expression can contain the constants "PI", "E", "PHI",
2355 "AVTB" (the default timebase), and defaults to the value "AVTB".
2359 Provide a frei0r source.
2361 To enable compilation of this filter you need to install the frei0r
2362 header and configure FFmpeg with --enable-frei0r.
2364 The source supports the syntax:
2366 @var{size}:@var{rate}:@var{src_name}[@{=|:@}@var{param1}:@var{param2}:...:@var{paramN}]
2369 @var{size} is the size of the video to generate, may be a string of the
2370 form @var{width}x@var{height} or a frame size abbreviation.
2371 @var{rate} is the rate of the video to generate, may be a string of
2372 the form @var{num}/@var{den} or a frame rate abbreviation.
2373 @var{src_name} is the name to the frei0r source to load. For more
2374 information regarding frei0r and how to set the parameters read the
2375 section @ref{frei0r} in the description of the video filters.
2377 Some examples follow:
2379 # generate a frei0r partik0l source with size 200x200 and framerate 10
2380 # which is overlayed on the overlay filter main input
2381 frei0r_src=200x200:10:partik0l=1234 [overlay]; [in][overlay] overlay
2384 @section rgbtestsrc, testsrc
2386 The @code{rgbtestsrc} source generates an RGB test pattern useful for
2387 detecting RGB vs BGR issues. You should see a red, green and blue
2388 stripe from top to bottom.
2390 The @code{testsrc} source generates a test video pattern, showing a
2391 color pattern, a scrolling gradient and a timestamp. This is mainly
2392 intended for testing purposes.
2394 Both sources accept an optional sequence of @var{key}=@var{value} pairs,
2395 separated by ":". The description of the accepted options follows.
2400 Specify the size of the sourced video, it may be a string of the form
2401 @var{width}x@var{heigth}, or the name of a size abbreviation. The
2402 default value is "320x240".
2405 Specify the frame rate of the sourced video, as the number of frames
2406 generated per second. It has to be a string in the format
2407 @var{frame_rate_num}/@var{frame_rate_den}, an integer number, a float
2408 number or a valid video frame rate abbreviation. The default value is
2412 Set the sample aspect ratio of the sourced video.
2415 Set the video duration of the sourced video. The accepted syntax is:
2417 [-]HH[:MM[:SS[.m...]]]
2420 See also the function @code{av_parse_time()}.
2422 If not specified, or the expressed duration is negative, the video is
2423 supposed to be generated forever.
2426 For example the following:
2428 testsrc=duration=5.3:size=qcif:rate=10
2431 will generate a video with a duration of 5.3 seconds, with size
2432 176x144 and a framerate of 10 frames per second.
2434 @c man end VIDEO SOURCES
2436 @chapter Video Sinks
2437 @c man begin VIDEO SINKS
2439 Below is a description of the currently available video sinks.
2443 Buffer video frames, and make them available to the end of the filter
2446 This sink is mainly intended for a programmatic use, in particular
2447 through the interface defined in @file{libavfilter/buffersink.h}.
2449 It does not require a string parameter in input, but you need to
2450 specify a pointer to a list of supported pixel formats terminated by
2451 -1 in the opaque parameter provided to @code{avfilter_init_filter}
2452 when initializing this sink.
2456 Null video sink, do absolutely nothing with the input video. It is
2457 mainly useful as a template and to be employed in analysis / debugging
2460 @c man end VIDEO SINKS