[Ffmpeg-devel] Random crashes when using libavcodec in different threads
Mon Jul 25 13:57:56 CEST 2005
I'm trying too integrate/use libavcodec in my own program and got it working
as long it's running "alone". That means I'm using multiple threads to encode
different movies (to *.vob) on a smp system. (I'm _not_ interested in
accelerating the encoding of a _single_ movie by using the
multi-thread-capabilities of ffmpeg!)
Problem: My program crashes randomly at the beginning when I'm for example
using libav* in two threads. Then one of the threads dies in
"ff_estimate_p_frame_motion" and the other was for example in
"MPV_common_init_mmx" or "ff_dct_sse2" or "dsputil_init_pix_mmx".
Maybe it's somehow mmx, sse*- register-save/restore related?
The threads are of course completely independent of each other, everyone has
it's own set of context-variables etc. It should be comparable to starting to
processes of ffmpeg at nearly the same time. The crash seems to get
extremely more unlikely if the threads don't start at the "same" time but for
example 500 ms later. But I don't think that's a real solution, it just makes
it less likely to crash. (Although I haven't seen a crash since this
My question: Is there anything that I can/should lock before calling a certain
av_* function? Can somebody explain what might be a problem? Sorry, if I gave
you too few info.
Thank you very much in advance,
More information about the ffmpeg-devel