Improve documentation for the -pass and -passlog options. Add mention

to how the log file is used and specify the default log file name.

Originally committed as revision 15969 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Stefano Sabatini 2008-12-01 08:27:53 +00:00
parent 11c0f9eca1
commit c2902c9c66

View File

@ -439,10 +439,11 @@ tell that the raw codec data must be copied as is.
Use same video quality as source (implies VBR).
@item -pass @var{n}
Select the pass number (1 or 2). It is useful to do two pass
encoding. The statistics of the video are recorded in the first
pass and the video is generated at the exact requested bitrate
in the second pass.
Select the pass number (1 or 2). It is used to do two-pass
video encoding. The statistics of the video are recorded in the first
pass into a log file (see also the option -passlogfile),
and in the second pass that log file is used to generate the video
at the exact requested bitrate.
On pass 1, you may just deactivate audio and set output to null,
examples for Windows and Unix:
@example
@ -451,7 +452,9 @@ ffmpeg -i foo.mov -vcodec libxvid -pass 1 -an -f rawvideo -y /dev/null
@end example
@item -passlogfile @var{file}
Set two pass logfile name to @var{file}.
Set two-pass log file name to @var{file}. Default name is
@file{ffmpeg2pass-N.log}, where N is a number specific to the output
stream.
@item -newvideo
Add a new video stream to the current output stream.