The special parameter "auto", signifies that the filter will
automatically select the output format depending on the output filter.
-Some examples follow.
+@subsection Examples
@itemize
@item
@end table
@subsection Examples
+
@itemize
@item
Fade in first 15 seconds of audio:
If inputs do not have the same duration, the output will stop with the
shortest.
-Example: merge two mono files into a stereo stream:
+@subsection Examples
+
+@itemize
+@item
+Merge two mono files into a stereo stream:
@example
amovie=left.wav [l] ; amovie=right.mp3 [r] ; [l] [r] amerge
@end example
-Example: multiple merges:
+@item
+Multiple merges:
@example
ffmpeg -f lavfi -i "
amovie=input.mkv:si=0 [a0];
amovie=input.mkv:si=5 [a5];
[a0][a1][a2][a3][a4][a5] amerge=inputs=6" -c:a pcm_s16le output.mkv
@end example
+@end itemize
@section amix
@var{key}=@var{value} pairs, separated by ":". See the
ffmpeg-resampler manual for the complete list of supported options.
-For example, to resample the input audio to 44100Hz:
+@subsection Examples
+
+@itemize
+@item
+Resample the input audio to 44100Hz:
@example
aresample=44100
@end example
-To stretch/squeeze samples to the given timestamps, with a maximum of 1000
+@item
+Stretch/squeeze samples to the given timestamps, with a maximum of 1000
samples per second compensation:
@example
aresample=async=1000
@end example
+@end itemize
@section asetnsamples
specified then the filter will assume nominal 1.0 tempo. Tempo must
be in the [0.5, 2.0] range.
-For example, to slow down audio to 80% tempo:
+@subsection Examples
+
+@itemize
+@item
+Slow down audio to 80% tempo:
@example
atempo=0.8
@end example
-For example, to speed up audio to 125% tempo:
+@item
+To speed up audio to 125% tempo:
@example
atempo=1.25
@end example
+@end itemize
@section earwax
specified value) or amplitude ratio. Default is -60dB, or 0.001.
@end table
+@subsection Examples
+
+@itemize
+@item
Detect 5 seconds of silence with -50dB noise tolerance:
@example
silencedetect=n=-50dB:d=5
@end example
+@item
Complete example with @command{ffmpeg} to detect silence with 0.0001 noise
tolerance in @file{silence.mp3}:
@example
ffmpeg -f lavfi -i amovie=silence.mp3,silencedetect=noise=0.0001 -f null -
@end example
+@end itemize
@section asyncts
Synchronize audio data with timestamps by squeezing/stretching it and/or
All volumes are in decibels relative to the maximum PCM value.
+@subsection Examples
+
Here is an excerpt of the output:
@example
[Parsed_volumedetect_0 @ 0xa23120] mean_volume: -27 dB
@end table
-For example:
+@subsection Examples
+
@example
abuffer=44100:s16p:stereo
@end example
@subsection Examples
@itemize
-
@item
Generate silence:
@example
@end example
@item
-
Generate a sin signal with frequency of 440 Hz, set sample rate to
8000 Hz:
@example
@end table
-Follow some examples:
+@subsection Examples
+
+@itemize
+@item
+Set the sample rate to 48000 Hz and the channel layout to AV_CH_LAYOUT_MONO.
@example
-# set the sample rate to 48000 Hz and the channel layout to AV_CH_LAYOUT_MONO.
anullsrc=r=48000:cl=4
+@end example
-# same as
+@item
+Do the same operation with a more obvious syntax:
+@example
anullsrc=r=48000:cl=mono
@end example
+@end itemize
@section abuffer
Buffer audio frames, and make them available to the filter chain.
@end table
@end table
-Some examples follow.
+@subsection Examples
@itemize
-
@item
Apply transition from bottom layer to top layer in first 10 seconds:
@example
A value of 0 will disable the effect.
@end table
-Some examples follow.
+@subsection Examples
@itemize
@item
for @var{y} may depend on @var{x}.
@subsection Examples
+
@itemize
@item
Crop area with size 100x100 at position (12,34).
@end table
-Some examples follow.
+@subsection Examples
@itemize
-
@item
Set a rectangle covering the area with top left corner coordinates 0,0
and size 100x77, setting a band of size 10:
Set the thickness of the box edge. Default value is @code{4}.
@end table
-Some examples follow:
+@subsection Examples
+
@itemize
@item
Draw a black box around the edge of the input image:
@subsection Examples
-Some examples follow.
-
@itemize
-
@item
Draw "Test Text" with font FreeSerif, using the default values for the
optional parameters.
@end table
@subsection Examples
+
@itemize
@item
Fade in first 30 frames of video:
The filter accepts a list of pixel format names, separated by ":",
for example "yuv420p:monow:rgb24".
-Some examples follow:
+@subsection Examples
+
+@itemize
+@item
+Convert the input video to the format @var{yuv420p}
@example
-# convert the input video to the format "yuv420p"
format=yuv420p
+@end example
-# convert the input video to any of the formats in the list
+Convert the input video to any of the formats in the list
+@example
format=yuv420p:yuv444p:yuv410p
@end example
+@end itemize
@section fps
The number and kind of parameters depend on the loaded effect. If an
effect parameter is not specified the default value is set.
-Some examples follow:
+@subsection Examples
@itemize
@item
For functions, if @var{x} and @var{y} are outside the area, the value will be
automatically clipped to the closer edge.
-Some examples follow:
+@subsection Examples
@itemize
@item
In this case @var{hue} is expressed in degrees.
-Some examples follow:
+@subsection Examples
+
@itemize
@item
Set the hue to 90 degrees and the saturation to 1.0:
of the corresponding MPlayer filters. For detailed instructions check
the "VIDEO FILTERS" section in the MPlayer manual.
-Some examples follow:
+@subsection Examples
+
@itemize
@item
Adjust gamma, brightness, contrast:
The filter accepts a list of pixel format names, separated by ":",
for example "yuv420p:monow:rgb24".
-Some examples follow:
+@subsection Examples
+
+@itemize
+@item
+Force libavfilter to use a format different from @var{yuv420p} for the
+input to the vflip filter:
@example
-# force libavfilter to use a format different from "yuv420p" for the
-# input to the vflip filter
noformat=yuv420p,vflip
+@end example
-# convert the input video to any of the formats not contained in the list
+@item
+Convert the input video to any of the formats not contained in the list:
+@example
noformat=yuv420p:yuv444p:yuv410p
@end example
+@end itemize
@section noise
@end table
@end table
-Some examples follow:
-@example
+@subsection Examples
+
Add temporal and uniform noise to input video:
+@example
noise=alls=20:allf=t+u
@end example
@option{chroma_amount}.
@end table
-Some examples follow:
+@subsection Examples
+
@itemize
@item
Apply strong luma sharpen effect:
@end table
-Example of real-time graph using @command{ffplay}, with a EBU scale meter +18:
+@subsection Examples
+
+@itemize
+@item
+Real-time graph using @command{ffplay}, with a EBU scale meter +18:
@example
ffplay -f lavfi -i "amovie=input.mp3,ebur128=video=1:meter=18 [out0][out1]"
@end example
+@item
Run an analysis with @command{ffmpeg}:
@example
ffmpeg -nostats -i input.mp3 -filter_complex ebur128 -f null -
@end example
+@end itemize
@section settb, asettb
Different frame rates are acceptable but will result in variable frame rate
at output; be sure to configure the output file to handle it.
-Examples:
+@subsection Examples
+
@itemize
@item
Concatenate an opening, an episode and an ending, all in bilingual version
Specify the video size for the output. Default value is "600x240".
@end table
-Some examples follow.
+@subsection Examples
+
@itemize
@item
Output the input file audio and the corresponding video representation
movie --> scale--> deltapts1 -------+
@end example
-Some examples follow.
+@subsection Examples
@itemize
@item