[Libav-user] Stack alignment page fault using yadif/libavfilter

[Francesco Pretto]

Hello, I'm having stack alignment related page faults using a simple
filter chain with "yadif=1:-1". The platform is win32 and the
executable is generated with MSVC++ using the frequent builds from
HawkEye[1]. I'm pretty sure it's stack alignment related because the I
the page fault in the middle of many SSE instructions (part of the
yadif optimized code?). It does randomly works (confirming me that is
really an stack alignment problem), saving first 5 deinterlaced frames
as ppm images. Seeing no complains from other users, I guess this
problem is specific to MSVC++ users or other compilers/architectures.
Still, I see similar problems has been fixed in the past, so I think
you may be interested in knowing why it does crash instead (maybe) of
just returning with an error message. I'd like to help in debugging
this issue. I created a small oo c++ sample "wrapper" to libav* which
I use in a test program which manifest the problem here (main in
Test.cpp). I tried to use most recent api (av_read_frame,
avcodec_decode_video2). Surely it does compile on gcc with simple
edits. I'd like to test it in gcc myself, but do you know any linux
distro where I can easily test a recent ffmpeg build (and dev
libraries)?

I opened a ticket [2]. There's a simpler C99 sample there (but less
readable, IMO, because is ffmpeg quick stripped code).

[1] http://hawkeye.arrozcru.org/
[2] https://ffmpeg.org/trac/ffmpeg/ticket/25
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