[Ffmpeg-devel] [BUG] Error: 2pass curve failed to converge

[Corey Hickey]

Corey Hickey wrote:
> Hi,
> 
> This bug is a bit elusive; it only happens with some source videos with
> some parameters, and is not always the same between amd64 and i386. In
> each case, the second pass fails immediately with the error:
> 
> [mpeg4 @ 0xc840d0]Error: 2pass curve failed to converge
> 
> ========================================================================
> I can reproduce this with mencoder r18679 and with ffmpeg
> r5780--both from today. I have attached the full output of ffmpeg, but I
> think this is easy to reproduce. Here are the steps:
> 
> $ wget http://samples.mplayerhq.hu/MPEG1/zelda%20first%20commercial.mpeg
> 
> $ for i in 1 2 ; do /usr/local/src/ffmpeg/ffmpeg -acodec copy -i zelda\
> first\ commercial.mpeg -b 817 -pass $i -y test.avi ; done
> 
> -or-
> 
> $ for i in 1 2 ; do mencoder -ovc lavc -lavcopts vbitrate=817:vpass=$i
> -o /dev/null -nosound "zelda first commercial.mpeg" ; done
> 
> The bitrate in the above commands is significant; 817 fails for me on
> both amd64 and i386 (Pentium 4).
> 
> ========================================================================
> These particular problems only started occurring after ffmpeg r5422;
> reverting that commit makes them go away. I reported the error in the
> 5422 commit thread.
> 
> http://lists.mplayerhq.hu/pipermail/ffmpeg-cvslog/2006-May/002348.html

Can anybody fix this? The problem gets reported somewhat regularly on 
the mplayer/mencoder user lists. If I could fix it myself I would, but 
the bug is out of my league...

I don't want to advocate reverting r5422, since doing so would only mask 
the bug, but functionally it would still be an improvement over what has 
been happening.

-Corey