MSVC uses %Id for size_t and ptrdiff_t

[cyril]

Summary of the bug: A badly formatted log in mjpegdec.c just make ffmpeg throw an exception when log is at DEBUG level.

In mjpegdec.c at line 1861:
av_log(avctx, AV_LOG_DEBUG, "marker=%x avail_size_in_buf=%td\n",

%td should be replaced by %d

[cyril]

I didn't know that %td was one of the new formatting rules of printf().
I don't have the rights to close a track, please feel free to do so.

[Carl Eugen Hoyos]

How can I trigger the exception?

[cyril]

You'll have to develop a Visual C++ 2010 application using FFmpeg dlls, which is redirecting avlog() streams to _vsntprintf_s().
As VC++ 2010 doesn't support %td, _vsntprintf_s just raise an invalid formatter exception.

[Carl Eugen Hoyos]

Do I understand correctly that this is not reproducible with newer versions of Visual Studio? A "fix" is possible but this is not a regression and if newer MS compilers do not show this behaviour, I wonder if a possible change is worth the effort.

[cyril]

I've just checked MSDN and VC++ 2013 still have the same issue: %td and %ti aren't supported at all.
Anyway as I stated in "comment 1", I don't think it's worth the effort as it can easily be fixed with a workaround, so feel free to close this track.

[Carl Eugen Hoyos]

How does your specific work-around look like?

[cyril]

Quite simple: I replace all those %td by %ld before passing them to VC++ printf functions

[Carl Eugen Hoyos]

I intend to work on this issue.

[Carl Eugen Hoyos]

Could you test if attached patch fixes the issue for you?

[cyril]

I'll test it later but if it works it won't be enough as %ti is also used in FFmpeg.

[Carl Eugen Hoyos]

I had just realized this, patch updated.

[Carl Eugen Hoyos]

Updated once more for size_t and correct specifier according to ​msdn.

[Andrey]

Thanks for a fix!

[Carl Eugen Hoyos]

Replying to nikolaynnov:

Thanks for a fix!

Sorry if I misunderstand: Did you test the patch and it fixes an issue for you?
I unfortunately cannot test...

[cyril]

Sorry for the late reply.
I've just tested your patch on a few problematic files and now it's working fine with MSVC, the debug output doesn't cause any crash anymore.

[Carl Eugen Hoyos]

Should be fixed in ced0d6c1 - thank you for the report and the testing!