[Ffmpeg-devel] Bug in multithreaded h/x264 encoding

[Måns Rullgård]

Erik Slagter <erik at slagter.name> writes:

> On Sun, 2005-06-19 at 13:12 +0200, M?ns Rullg?rd wrote:
>> >> > This doesn't work when I specify -threads 2 as well, without it it's
>> >> > fine:
>> >> >
>> >> > ffmpeg -y -i input.vob -aspect 4:3 -g 25 -qscale 6 -bf 2 -coder 1 \
>> >> >  -ab 64 -async 1 -acodec aac -vcodec h264 -f mp4 output.mp4
>> >> >
>> >> > Large parts of the image are completly mangled all of the time. I guess
>> >> > it can be reproduced with any input.
>> >> 
>> >> That's a fairly long command line.  Does the bug still show if you
>> >> simplify it a bit, such as disable B frames?  Does the x264 command
>> >> line interface work?
>> >
>> > It's gone when the -coder 1 is removed (CABAC iirc).
>> 
>> Does the x264 command line work properly?  I can't imagine how the
>> lavc wrapper could misbehave with cabac enabled.
>
> Can you tell me what command line options of x264 _exactly_ correspond
> to the ones I used with ffmpeg?

x264 -b 2 -I 25 -q 27 --sar 16:15 --threads 2

> Maybe it's the mp4 muxer that messes up?

Did you try another container?  MPEGTS and AVI should both work well
enough to test this theory.

-- 
M?ns Rullg?rd
mru at inprovide.com