[FFmpeg-cvslog] Document null muxer.

[Stefano Sabatini]

ffmpeg | branch: master | Stefano Sabatini <stefano.sabatini-lala at poste.it> | Mon Jan 31 15:01:46 2011 +0100| [7e7afb3d5441d9a0c45b49ada3fc1e9ddea91a8c] | committer: Michael Niedermayer

Document null muxer.

Signed-off-by: Janne Grunau <janne-ffmpeg at jannau.net>
(cherry picked from commit f4acb837eb4af74996b678f3f55eaa66c47a66ee)

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=7e7afb3d5441d9a0c45b49ada3fc1e9ddea91a8c
---

 doc/muxers.texi |   22 ++++++++++++++++++++++
 1 files changed, 22 insertions(+), 0 deletions(-)

diff --git a/doc/muxers.texi b/doc/muxers.texi
index d98abef..d661c96 100644
--- a/doc/muxers.texi
+++ b/doc/muxers.texi
@@ -109,4 +109,26 @@ ffmpeg -i file.mpg -acodec copy -vcodec copy \
      -y out.ts
 @end example
 
+ at section null
+
+Null muxer.
+
+This muxer does not generate any output file, it is mainly useful for
+testing or benchmarking purposes.
+
+For example to benchmark decoding with @file{ffmpeg} you can use the
+command:
+ at example
+ffmpeg -benchmark -i INPUT -f null out.null
+ at end example
+
+Note that the above command does not read or write the @file{out.null}
+file, but specifying the output file is required by the @file{ffmpeg}
+syntax.
+
+Alternatively you can write the command as:
+ at example
+ffmpeg -benchmark -i INPUT -f null -
+ at end example
+
 @c man end MUXERS