[MPlayer-users] segment fault when testing xvmc video output

[Zhenyu Wang]

When testing mplayer vo xvmc on 965GM, I encounter seg fault bug
that doesn't happen before. This still happens with today's mplayer
svn tip, but seems fine in ubuntu karmic's svn20090426 version.

I've tested with T61 with 965GM graphics device, cpu is Core 2 Duo.
And another Lenovo S10e with Atom N270 and 945GME graphics. Both can
trigger this problem.

Full session log within gdb like below:

(gdb) file ./mplayer
Reading symbols from /home/devel/mplayer/mplayer-svn/mplayer...done.
(gdb) run -nosound -vo xvmc -vc ffmpeg12mc ~/samples/dothack2.mpg 
Starting program: /home/devel/mplayer/mplayer-svn/mplayer -nosound -vo xvmc -vc ffmpeg12mc ~/samples/dothack2.mpg
[Thread debugging using libthread_db enabled]
MPlayer SVN-r29725-4.3.4 (C) 2000-2009 MPlayer Team

Playing /root/samples/dothack2.mpg.
MPEG-PS file format detected.
VIDEO:  MPEG2  720x576  (aspect 3)  25.000 fps  7000.0 kbps (875.0 kbyte/s)
Xlib:  extension "XFree86-VidModeExtension" missing on display ":0.0".
vo_xvmc: X-Video extension 2.2
vo_xvmc: X-Video MotionCompensation Extension version 1.1
==========================================================================
Forced video codec: ffmpeg12mc
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
[VD_FFMPEG] XVMC accelerated codec.
[VD_FFMPEG] XVMC-accelerated MPEG-2.
[VD_FFMPEG] XVMC-accelerated MPEG-2.
Selected video codec: [ffmpeg12mc] vfm: ffmpeg (FFmpeg MPEG-1/2 (XvMC))
==========================================================================
Audio: no sound
Starting playback...
[VD_FFMPEG] Trying pixfmt=0.
[VD_FFMPEG] XVMC-accelerated MPEG-2.
VDec: vo config request - 720 x 576 (preferred colorspace: MPEG1/2 Motion Compensation and IDCT)
vo_xvmc: Found matching surface with id=32315659 on 90 port at 0 adapter
VDec: using MPEG1/2 Motion Compensation as output csp (no 1)
Movie-Aspect is 1.78:1 - prescaling to correct movie aspect.
VO: [xvmc] 720x576 => 1024x576 MPEG1/2 Motion Compensation 
vo_xvmc: Found matching surface with id=32315659 on 90 port at 0 adapter
vo_xvmc: Using Xv Adaptor #0 (Intel(R) Textured Video)
vo_xvmc: Port 90 grabed
[intel_xvmc] info: decoder type is i965 MPEG2 MC decoder
vo_xvmc: Allocated Direct Context
vo_xvmc: data_blocks allocated
vo_xvmc: mv_blocks allocated
vo_xvmc: Motion Compensation context allocated - 8 surfaces
vo_xvmc: idct=0 unsigned_intra=1
vo_xvmc: looking for OSD support
vo_xvmc: No OSD support for this mode
[VD_FFMPEG] XVMC-accelerated MPEG-2.
    Program received signal SIGSEGV, Segmentation fault.
    in clear_blocks_sse (blocks=0xb763f008) at x86/dsputil_mmx.c:532
    {\
(gdb) bt
#0  0x08586264 in clear_blocks_sse (blocks=0xb763f008) at x86/dsputil_mmx.c:532
#1  0x08444476 in mpeg_decode_mb (s1=0x8d98c10, mb_y=0, buf=0xbfffbf64, buf_size=37356) at mpeg12.c:275
#2  mpeg_decode_slice (s1=0x8d98c10, mb_y=0, buf=0xbfffbf64, buf_size=37356) at mpeg12.c:1772
#3  0x084487ff in decode_chunks (avctx=0x8d98870, picture=0x8d98790, data_size=0xbfffc0a4, buf=0xb77d3008 "", buf_size=37536)
	        at mpeg12.c:2435
#4  0x084495b6 in mpeg_decode_frame (avctx=0x8d98870, data=0x8d98790, data_size=0xbfffc0a4, avpkt=0xbfffc050) at mpeg12.c:2290
#5  0x083541fd in avcodec_decode_video2 (avctx=0x8d98870, picture=0x8d98790, got_picture_ptr=0xbfffc0a4, avpkt=0xbfffc050) at utils.c:584
#6  0x08235e9d in decode (sh=0x8d8c480, data=0xb77d3008, len=37536, flags=0) at libmpcodecs/vd_ffmpeg.c:789
#7  0x08131e5b in decode_video (sh_video=0x8d8c480, start=0xb77d3008 "", in_size=37536, drop_frame=0, pts=0.039999999105930328)
		    at libmpcodecs/dec_video.c:365
#8  0x080b6e00 in update_video (argc=7, argv=0xbffff384) at mplayer.c:2322
#9  main (argc=7, argv=0xbffff384) at mplayer.c:3740
(gdb) 

Feel free to ask for more info you need for this bug.

Thanks.

-- 
Open Source Technology Center, Intel ltd.

$gpg --keyserver wwwkeys.pgp.net --recv-keys 4D781827
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