From a4effe432f4aa59d52465b88589f92addf3afd3e Mon Sep 17 00:00:00 2001 From: Stefano Sabatini Date: Mon, 31 Jan 2011 15:20:09 +0100 Subject: Add documentation for the crc muxer. Signed-off-by: Janne Grunau --- doc/muxers.texi | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'doc/muxers.texi') diff --git a/doc/muxers.texi b/doc/muxers.texi index d661c9694d..63aa95c317 100644 --- a/doc/muxers.texi +++ b/doc/muxers.texi @@ -18,6 +18,38 @@ enabled muxers. A description of some of the currently available muxers follows. +@section crc + +CRC (Cyclic Redundancy Check) testing format. + +This muxer computes and prints the Adler-32 CRC of all the input audio +and video frames. 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 single line of the form: +CRC=0x@var{CRC}, where @var{CRC} is a hexadecimal number 0-padded to +8 digits containing the CRC for all the decoded input frames. + +For example to compute the CRC of the input, and store it in the file +@file{out.crc}: +@example +ffmpeg -i INPUT -f crc out.crc +@end example + +You can print the CRC to stdout with the command: +@example +ffmpeg -i INPUT -f crc - +@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 the input audio converted to PCM unsigned 8-bit +and the input video converted to MPEG-2 video, use the command: +@example +ffmpeg -i INPUT -acodec pcm_u8 -vcodec mpeg2video -f crc - +@end example + @section image2 Image file muxer. -- cgit v1.2.3