[FFmpeg-user] mpeg2 bufsize question

Carl Eugen Hoyos cehoyos at ag.or.at
Wed Jan 18 00:11:27 CET 2012

Dave P <lists.davep <at> gmail.com> writes:

> I recall reading on here somewhere that -f vob was for program
> streams.

I believe it tries to conform to the DVD standard (at least that is what I would
expect) and this standard is certainly not written for 1920x1080.
-f mpeg (or .mpg as output filename) forces mpeg program streams.

> I get the same result without it. Muxrate values ranging from 2M to 25M still
> generate errors.

I can now reproduce your problem (I originally tested with an Apple trailer that
starts with a still and only outputs the warnings / errors later).

I suspect the bug is that -bufsize (which is the right option) does not work
correctly with -qscale, a work-around is to change (current) line 377 in
libavformat/mpegenc.c "stream->max_buffer_size =" to a significantly larger
value, I tested "10*" successfully on mentioned trailer.
(The line is the one following the warning message "VBV buffer size not set".)

Carl Eugen

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