[PATCH] Add documentation for the crc muxer.

Stefano Sabatini stefano.sabatini-lala
Mon Jan 31 15:20:09 CET 2011

 doc/muxers.texi |   33 +++++++++++++++++++++++++++++++++
 1 files changed, 33 insertions(+), 0 deletions(-)

diff --git a/doc/muxers.texi b/doc/muxers.texi
index d661c96..da215e8 100644
--- a/doc/muxers.texi
+++ b/doc/muxers.texi
@@ -18,6 +18,39 @@ enabled muxers.
 A description of some of the currently available muxers follows.
+ at 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 the CRC is computed on the decoded input
+audio and video frames converted respectively to rawvideo and signed
+16-bit rawaudio.
+The output of the muxer consists of a single line of the form:
+CRC=0x at var{CRC}, where @var{CRC} is an 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
+ at file{out.crc}:
+ at example
+ffmpeg -i INPUT -f crc out.crc
+ at end example
+You can print the CRC to stdout with the command (using the
+ at file{sh} shell syntax):
+ at example
+ffmpeg -i INPUT -f crc -
+ at 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:
+ at example
+ffmpeg -i INPUT -acodec pcm_u8 -vcodec mpeg2video -f crc -
+ at end example
 @section image2
 Image file muxer.


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