[Ffmpeg-devel] Gray Scale decoding of MPEG4 data and debugginglibavcodec

Steve Lhomme steve.lhomme
Tue May 16 10:00:35 CEST 2006

Matt Schuckmann wrote:
> Yes really crash. Turns out it's not just the gray scale decoder mpeg4
> decoding in general is crashing. Seems to have something to do with my
> latest pull down of FFMPEG, I tested by old sandbox and it's seems to work
> ok.
> So I pulled down the latest FFMPEG stuff today and rebuilt and now I can't
> find the .lib files for linking with the shared libraries. Did you change
> the way things are built for the shared windows libraries?
> I understand you don't support MSVC how about another debugger that does
> work on a windows system?

gdb should work on MinGW+MSys/cygwin, if you're not afraid of working 
like 10 years ago.

Alternatively you can grab the sources of DrFFMPEG on SourceForge (part 
of DrDivX) that has an FFMPEG version built in MSVC. There's a pure 
debug build, a debug+ASM build (using a DLL for some of the ASM code) 
and a release build (without ASM). And it's usually enough to debug 
FFMPEG if the bug can be reproduced.


> Thanks
> Matt S.  
> -----Original Message-----
> From: ffmpeg-devel-bounces at mplayerhq.hu
> [mailto:ffmpeg-devel-bounces at mplayerhq.hu] On Behalf Of M?ns Rullg?rd
> Sent: Monday, May 15, 2006 12:23 PM
> To: FFMpeg development discussions and patches
> Subject: Re: [Ffmpeg-devel] Gray Scale decoding of MPEG4 data and
> debugginglibavcodec
> "Matt Schuckmann" <mschuck at imoveinc.com> writes:
>> I'm using just libavcodec with my application and I'm experimenting with
>> various options and formats and I'm having trouble decoding gray scale
>> images that have been encoded with libavcodec's MPEG4 encoder using the
>> CODEC_GRAY_FLAG flags option. 
>> The data appears to have encoded fine (well libavcodec didn't complain,
>> there is data in the file, and it's smaller than the original) but
> whenever
>> I try to decode it my app crashes on the call to avcodec_decode_video(). 
> Do you mean it really crashes, or just returns an error?  In case of a
> proper crash, please send a complete bug report as per the
> instructions on the web page.
>> Are there any special options or formats I need to set to make this work
>> (other than CODEC_GRAY_FLAG)?
>> Any help or suggestions would be much appreciated. 
>> This brings up another question; can anyone give me some guidance on how
> to
>> debug libavcodec in a windows environment? The best solution would be able
>> to debug it directly from MSVC++ .NET 2003 since that's my current working
>> environment but I'm not totally opposed something else. 
> We don't support msvc.  Sorry.

robUx4 on blog <http://robux4.blogspot.com/>

More information about the ffmpeg-devel mailing list