[Ffmpeg-devel] segfault during avcodec_close()

[Matthew Hodgson]

Hi all,

I'm experiencing a segfault when running avcodec_close() in one thread 
whilst avcodec_decode_video() is running in another.  Should 
avcodec_close() be threadsafe, or do I need to grab a lock to ensure the 
two don't collide?

Valgrind spews a lot of the following before dying:

==29697== Invalid read of size 1
==29697==    at 0x81449C2: guess_mv (error_resilience.c:501)
==29697==    by 0x8142747: ff_er_frame_end (error_resilience.c:905)
==29697==    by 0x8186412: ff_h263_decode_frame_end (h263dec.c:639)
==29697==    by 0x8184E9A: ff_h263_decode_frame (h263dec.c:815)
==29697==    by 0x8098A51: avcodec_decode_video (utils.c:376)
...
==29697==  Address 0x60D6C4F is 5,375 bytes inside a block of size 
54,928 free'd
==29697==    at 0x401A13C: free (vg_replace_malloc.c:235)
==29697==    by 0x8098C11: avcodec_default_free_buffers (utils.c:106)
==29697==    by 0x8099FC0: MPV_common_end (mpegvideo.c:552)
==29697==    by 0x81852E3: ff_h263_decode_end (h263dec.c:132)
==29697==    by 0x8098AE5: avcodec_close (utils.c:405)
==29697==    by 0x8082F78: teardown_ffmpeg (rtp.c:1441)
...


thanks,

Matthew.