[FFmpeg-user] Ticket#5936: Purple haze on ffmpeg mpeg4 decoding

[Toerless Eckert]

Thanks Carl Eugen and Michael for the quick fix of the bug.
I've tested it (works fine) and appended notes to the ticket.

Thanks Andy for educating me on git bisect.

Nice bug autodetect & workaround code in ffmpeg!

Cheers
    Toerless

On Sun, Nov 13, 2016 at 10:26:28AM +0000, Andy Furniss wrote:
> Toerless Eckert wrote:
> >Thanks a lot, Andy
> 
> Looking at trac it seems Carl Eugen beat me to it.
> 
> >Mind explaining how you did that trick with git bisect ?
> 
> In this case as you gave working revisions I started with those.
> 
> git tag shows lots and you can see that the more recent tags start with n.
> 
> so clean tree
> 
> make distclean
> git clean -dfx
> 
> git bisect start
> git bisect bad n2.3
> git bisect good n2.2.16
> 
> build - ./confugure --enable-gpl --disable-doc && make -j5
> test - ./ffplay ...
> 
> clean
> 
> git bisect good or bad repeat from build.
> 
> I haven't bisected ffmpeg for a while, this one was easy.
> Sometimes, historically,  a commit from libav ends up building
> avconv - you can clean and use git bisect skip to hopefully find
> a commit that doesn't.
> 
> When getting closer to the bad commit you can usually skip the
> clean/configure and just make to save a bit of build time. For ffmpeg it's
> not that bad anyway, but for bigger projects like kernels or llvm
> it's handy (when it works).
> 
> git bisect log will keep a record of progress so if you get stuck
> you can save a copy and in combination with git log or git reset --hard
> hopefully find different/closer starting points for a fresh bisect if
> you need to,
> 
> When you've finished clean up and git bisect reset to get back on master.
> 
> 
> 
> _______________________________________________
> ffmpeg-user mailing list
> ffmpeg-user at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
> 
> To unsubscribe, visit link above, or email
> ffmpeg-user-request at ffmpeg.org with subject "unsubscribe".

-- 
---
tte at cs.fau.de