Commit 77d4ed7a authored by Stefano Sabatini's avatar Stefano Sabatini Committed by Janne Grunau
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Add documentation for the framecrc muxer.


Signed-off-by: default avatarJanne Grunau <janne-ffmpeg@jannau.net>
parent a4effe43
......@@ -18,6 +18,7 @@ enabled muxers.
A description of some of the currently available muxers follows.
@anchor{crc}
@section crc
CRC (Cyclic Redundancy Check) testing format.
......@@ -50,6 +51,45 @@ and the input video converted to MPEG-2 video, use the command:
ffmpeg -i INPUT -acodec pcm_u8 -vcodec mpeg2video -f crc -
@end example
See also the @code{framecrc} muxer (@pxref{framecrc}).
@anchor{framecrc}
@section framecrc
Per-frame CRC (Cyclic Redundancy Check) testing format.
This muxer computes and prints the Adler-32 CRC for each decoded audio
and video frame. By default audio frames are converted to signed
16-bit raw audio and video frames to raw video before computing the
CRC.
The output of the muxer consists of a line for each audio and video
frame of the form: @var{stream_index}, @var{frame_dts},
@var{frame_size}, 0x@var{CRC}, where @var{CRC} is a hexadecimal
number 0-padded to 8 digits containing the CRC of the decoded frame.
For example to compute the CRC of each decoded frame in the input, and
store it in the file @file{out.crc}:
@example
ffmpeg -i INPUT -f framecrc out.crc
@end example
You can print the CRC of each decoded frame to stdout with the command:
@example
ffmpeg -i INPUT -f framecrc -
@end example
You can select the output format of each frame with @file{ffmpeg} by
specifying the audio and video codec and format. For example, to
compute the CRC of each decoded input audio frame converted to PCM
unsigned 8-bit and of each decoded input video frame converted to
MPEG-2 video, use the command:
@example
ffmpeg -i INPUT -acodec pcm_u8 -vcodec mpeg2video -f framecrc -
@end example
See also the @code{crc} muxer (@pxref{crc}).
@section image2
Image file muxer.
......
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