the corresponding numeric value defined in @file{libavutil/samplefmt.h}.
@var{channel_layout} specifies the channel layout, and can be a string
-or the corresponding number value defined in @file{libavutil/chlayout.h}.
+or the corresponding number value defined in @file{libavutil/audioconvert.h}.
@var{packing_format} specifies the type of packing in output, can be one
of "planar" or "packed", or the corresponding numeric values "0" or "1".
@item pos
position of the frame in the input stream, -1 if this information in
-unavailable and/or meanigless (for example in case of synthetic audio)
+unavailable and/or meaningless (for example in case of synthetic audio)
@item fmt
sample format name
if the packing format is planar, 0 if packed
@item checksum
-Adler-32 checksum of all the planes of the input frame
+Adler-32 checksum (printed in hexadecimal) of all the planes of the input frame
@item plane_checksum
-Adler-32 checksum for each input frame plane, expressed in the form
-"[@var{c0} @var{c1} @var{c2} @var{c3} @var{c4} @var{c5} @var{c6} @var{c7}]"
+Adler-32 checksum (printed in hexadecimal) for each input frame plane,
+expressed in the form "[@var{c0} @var{c1} @var{c2} @var{c3} @var{c4} @var{c5}
+@var{c6} @var{c7}]"
@end table
+@section earwax
+
+Make audio easier to listen to on headphones.
+
+This filter adds `cues' to 44.1kHz stereo (i.e. audio CD format) audio
+so that when listened to on headphones the stereo image is moved from
+inside your head (standard for headphones) to outside and in front of
+the listener (standard for speakers).
+
+Ported from SoX.
+
+@section volume
+
+Adjust the input audio volume.
+
+The filter accepts exactly one parameter @var{vol}, which expresses
+how the audio volume will be increased or decreased.
+
+Output values are clipped to the maximum value.
+
+If @var{vol} is expressed as a decimal number, and the output audio
+volume is given by the relation:
+@example
+@var{output_volume} = @var{vol} * @var{input_volume}
+@end example
+
+If @var{vol} is expressed as a decimal number followed by the string
+"dB", the value represents the requested change in decibels of the
+input audio power, and the output audio volume is given by the
+relation:
+@example
+@var{output_volume} = 10^(@var{vol}/20) * @var{input_volume}
+@end example
+
+Otherwise @var{vol} is considered an expression and its evaluated
+value is used for computing the output audio volume according to the
+first relation.
+
+Default value for @var{vol} is 1.0.
+
+@subsection Examples
+
+@itemize
+@item
+Half the input audio volume:
+@example
+volume=0.5
+@end example
+
+The above example is equivalent to:
+@example
+volume=1/2
+@end example
+
+@item
+Decrease input audio power by 12 decibels:
+@example
+volume=-12dB
+@end example
+@end itemize
+
@c man end AUDIO FILTERS
@chapter Audio Sources
abuffer=44100:1:3:1
@end example
+@section aevalsrc
+
+Generate an audio signal specified by an expression.
+
+This source accepts in input one or more expressions (one for each
+channel), which are evaluated and used to generate a corresponding
+audio signal.
+
+It accepts the syntax: @var{exprs}[::@var{options}].
+@var{exprs} is a list of expressions separated by ":", one for each
+separate channel. The output channel layout depends on the number of
+provided expressions, up to 8 channels are supported.
+
+@var{options} is an optional sequence of @var{key}=@var{value} pairs,
+separated by ":".
+
+The description of the accepted options follows.
+
+@table @option
+
+@item nb_samples, n
+Set the number of samples per channel per each output frame,
+default to 1024.
+
+@item sample_rate, s
+Specify the sample rate, default to 44100.
+@end table
+
+Each expression in @var{exprs} can contain the following constants:
+
+@table @option
+@item n
+number of the evaluated sample, starting from 0
+
+@item t
+time of the evaluated sample expressed in seconds, starting from 0
+
+@item s
+sample rate
+
+@end table
+
+@subsection Examples
+
+@itemize
+
+@item
+Generate silence:
+@example
+aevalsrc=0
+@end example
+
+@item
+
+Generate a sin signal with frequence of 440 Hz, set sample rate to
+8000 Hz:
+@example
+aevalsrc="sin(440*2*PI*t)::s=8000"
+@end example
+
+@item
+Generate white noise:
+@example
+aevalsrc="-2+random(0)"
+@end example
+
+@item
+Generate an amplitude modulated signal:
+@example
+aevalsrc="sin(10*2*PI*t)*sin(880*2*PI*t)"
+@end example
+
+@item
+Generate 2.5 Hz binaural beats on a 360 Hz carrier:
+@example
+aevalsrc="0.1*sin(2*PI*(360-2.5/2)*t) : 0.1*sin(2*PI*(360+2.5/2)*t)"
+@end example
+
+@end itemize
+
@section amovie
Read an audio stream from a movie container.
pixel format "yuv422p" @var{hsub} is 2 and @var{vsub} is 1.
@end table
-The radius must be a non-negative number, and must be not greater than
+The radius must be a non-negative number, and must not be greater than
the value of the expression @code{min(w,h)/2} for the luma and alpha planes,
and of @code{min(cw,ch)/2} for the chroma planes.
The parameters are expressions containing the following constants:
@table @option
-@item E, PI, PHI
-the corresponding mathematical approximated values for e
-(euler number), pi (greek PI), PHI (golden ratio)
-
@item x, y
the computed values for @var{x} and @var{y}. They are evaluated for
each new frame.
@end itemize
+@section deshake
+
+Attempt to fix small changes in horizontal and/or vertical shift. This
+filter helps remove camera shake from hand-holding a camera, bumping a
+tripod, moving on a vehicle, etc.
+
+The filter accepts parameters as a string of the form
+"@var{x}:@var{y}:@var{w}:@var{h}:@var{rx}:@var{ry}:@var{edge}:@var{blocksize}:@var{contrast}:@var{search}:@var{filename}"
+
+A description of the accepted parameters follows.
+
+@table @option
+
+@item x, y, w, h
+Specify a rectangular area where to limit the search for motion
+vectors.
+If desired the search for motion vectors can be limited to a
+rectangular area of the frame defined by its top left corner, width
+and height. These parameters have the same meaning as the drawbox
+filter which can be used to visualise the position of the bounding
+box.
+
+This is useful when simultaneous movement of subjects within the frame
+might be confused for camera motion by the motion vector search.
+
+If any or all of @var{x}, @var{y}, @var{w} and @var{h} are set to -1
+then the full frame is used. This allows later options to be set
+without specifying the bounding box for the motion vector search.
+
+Default - search the whole frame.
+
+@item rx, ry
+Specify the maximum extent of movement in x and y directions in the
+range 0-64 pixels. Default 16.
+
+@item edge
+Specify how to generate pixels to fill blanks at the edge of the
+frame. An integer from 0 to 3 as follows:
+@table @option
+@item 0
+Fill zeroes at blank locations
+@item 1
+Original image at blank locations
+@item 2
+Extruded edge value at blank locations
+@item 3
+Mirrored edge at blank locations
+@end table
+
+The default setting is mirror edge at blank locations.
+
+@item blocksize
+Specify the blocksize to use for motion search. Range 4-128 pixels,
+default 8.
+
+@item contrast
+Specify the contrast threshold for blocks. Only blocks with more than
+the specified contrast (difference between darkest and lightest
+pixels) will be considered. Range 1-255, default 125.
+
+@item search
+Specify the search strategy 0 = exhaustive search, 1 = less exhaustive
+search. Default - exhaustive search.
+
+@item filename
+If set then a detailed log of the motion search is written to the
+specified file.
+
+@end table
+
@section drawbox
Draw a colored box on the input image.
Apply fade-in/out effect to input video.
It accepts the parameters:
-@var{type}:@var{start_frame}:@var{nb_frames}
+@var{type}:@var{start_frame}:@var{nb_frames}[:@var{options}]
@var{type} specifies if the effect type, can be either "in" for
fade-in, or "out" for a fade-out effect.
will have the same intensity as the input video, at the end of the
fade-out transition the output video will be completely black.
+@var{options} is an optional sequence of @var{key}=@var{value} pairs,
+separated by ":". The description of the accepted options follows.
+
+@table @option
+
+@item type, t
+See @var{type}.
+
+@item start_frame, s
+See @var{start_frame}.
+
+@item nb_frames, n
+See @var{nb_frames}.
+
+@end table
+
A few usage examples follow, usable too as test scenarios.
@example
# fade in first 30 frames of video
It takes two inputs and one output, the first input is the "main"
video on which the second input is overlayed.
-It accepts the parameters: @var{x}:@var{y}.
+It accepts the parameters: @var{x}:@var{y}[:@var{options}].
@var{x} is the x coordinate of the overlayed video on the main video,
-@var{y} is the y coordinate. The parameters are expressions containing
+@var{y} is the y coordinate. @var{x} and @var{y} are expressions containing
the following parameters:
@table @option
same as @var{overlay_w} and @var{overlay_h}
@end table
+@var{options} is an optional list of @var{key}=@var{value} pairs,
+separated by ":".
+
+The description of the accepted options follows.
+
+@table @option
+@item rgb
+If set to 1, force the filter to accept inputs in the RGB
+colorspace. Default value is 0.
+@end table
+
Be aware that frames are taken from each input video in timestamp
order, hence, if their initial timestamps differ, it is a a good idea
to pass the two inputs through a @var{setpts=PTS-STARTPTS} filter to
color=red@.3:WxH [over]; [in][over] overlay [out]
@end example
-You can chain togheter more overlays but the efficiency of such
+You can chain together more overlays but the efficiency of such
approach is yet to be tested.
@section pad
@section scale
-Scale the input video to @var{width}:@var{height} and/or convert the image format.
+Scale the input video to @var{width}:@var{height}[:@var{interl}=@{1|-1@}] and/or convert the image format.
The parameters @var{width} and @var{height} are expressions containing
the following constants:
@table @option
-@item E, PI, PHI
-the corresponding mathematical approximated values for e
-(euler number), pi (greek PI), phi (golden ratio)
-
@item in_w, in_h
the input width and height
The default value of @var{width} and @var{height} is 0.
+Valid values for the optional parameter @var{interl} are:
+
+@table @option
+@item 1
+force interlaced aware scaling
+
+@item -1
+select interlaced aware scaling depending on whether the source frames
+are flagged as interlaced or not
+@end table
+
Some examples follow:
@example
# scale the input video to a size of 200x100.
The expression can contain the following constants:
@table @option
-@item PI
-Greek PI
-
-@item PHI
-golden ratio
-
-@item E
-Euler number
-
@item n
the sequential number of the filtered frame, starting from 0
@item PTS
the presentation timestamp in input
-@item PI
-Greek PI
-
-@item PHI
-golden ratio
-
-@item E
-Euler number
-
@item N
the count of the input frame, starting from 0.
It is mainly useful for testing timebase configuration.
It accepts in input an arithmetic expression representing a rational.
-The expression can contain the constants "PI", "E", "PHI", "AVTB" (the
+The expression can contain the constants "AVTB" (the
default timebase), and "intb" (the input timebase).
The default value for the input is "intb".
@file{libavutil/avutil.h}.
@item checksum
-Adler-32 checksum of all the planes of the input frame
+Adler-32 checksum (printed in hexadecimal) of all the planes of the input frame
@item plane_checksum
-Adler-32 checksum of each plane of the input frame, expressed in the form
-"[@var{c0} @var{c1} @var{c2} @var{c3}]"
+Adler-32 checksum (printed in hexadecimal) of each plane of the input frame,
+expressed in the form "[@var{c0} @var{c1} @var{c2} @var{c3}]"
@end table
@section slicify
It accepts the following parameters:
@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}
-All the parameters but @var{scale_params} need to be explicitely
+All the parameters but @var{scale_params} need to be explicitly
defined.
Follows the list of the accepted parameters.
will generate a "dc_luma" test pattern.
-@section nullsrc
-
-Null video source, never return images. It is mainly useful as a
-template and to be employed in analysis / debugging tools.
-
-It accepts as optional parameter a string of the form
-@var{width}:@var{height}:@var{timebase}.
-
-@var{width} and @var{height} specify the size of the configured
-source. The default values of @var{width} and @var{height} are
-respectively 352 and 288 (corresponding to the CIF size format).
-
-@var{timebase} specifies an arithmetic expression representing a
-timebase. The expression can contain the constants "PI", "E", "PHI",
-"AVTB" (the default timebase), and defaults to the value "AVTB".
-
@section frei0r_src
Provide a frei0r source.
frei0r_src=200x200:10:partik0l=1234 [overlay]; [in][overlay] overlay
@end example
-@section rgbtestsrc, testsrc
+@section nullsrc, rgbtestsrc, testsrc
+
+The @code{nullsrc} source returns unprocessed video frames. It is
+mainly useful to be employed in analysis / debugging tools, or as the
+source for filters which ignore the input data.
The @code{rgbtestsrc} source generates an RGB test pattern useful for
detecting RGB vs BGR issues. You should see a red, green and blue
color pattern, a scrolling gradient and a timestamp. This is mainly
intended for testing purposes.
-Both sources accept an optional sequence of @var{key}=@var{value} pairs,
+These sources accept an optional sequence of @var{key}=@var{value} pairs,
separated by ":". The description of the accepted options follows.
@table @option
will generate a video with a duration of 5.3 seconds, with size
176x144 and a framerate of 10 frames per second.
+If the input content is to be ignored, @code{nullsrc} can be used. The
+following command generates noise in the luminance plane by employing
+the @code{mp=geq} filter:
+@example
+nullsrc=s=256x256, mp=geq=random(1)*255:128:128
+@end example
+
@c man end VIDEO SOURCES
@chapter Video Sinks
projects / ffmpeg / blobdiff