[MPlayer-users] All latest versions (since 0.90) crash in PentiumPro when CPU detection is enabled

zimon@iki.fi zimon at niksula.hut.fi
Fri Aug 22 13:36:25 CEST 2003

Seems like in Intel PentiumPro with the runtime CPU detection routine MPlayer
always crashes. Whenever I have downloaded and installed some MPlayer-*.rpm,
which has this autodetection compiled in, mlayer will crash. Also crashes
when I've compiled my own binary from the sources and CPU detection has been 
enabled.  When runtime CPU detection is disabled, then it works.

Tried to look around abit, but didn't notice this would be a known bug.

The bug is somewhere here, because if I let it continue after that manually 
set breakpoint, it crashes in fast_memcpy() with SIGSEGV: 

Breakpoint 1, fast_memcpy (to=0x84c03c0, from=0xbfffd360, len=65)
    at aclib.c:133
133                     memcpy(to, from, len); // prior to mmx we use the standart memcpy
(gdb) bt
#0  fast_memcpy (to=0x84c03c0, from=0xbfffd360, len=65) at aclib.c:133
#1  0x081da787 in init_rl (rl=0x8381340) at mpegvideo.c:843
#2  0x08257508 in h263_decode_init_vlc (s=0x84b4c00) at h263.c:2285
#3  0x08266c98 in ff_h263_decode_init (avctx=0x41) at h263dec.c:106
#4  0x081d836c in avcodec_open (avctx=0x84c03c0, codec=0x41) at utils.c:280
#5  0x080ec241 in init (sh=0x831d420) at vd_ffmpeg.c:256
#6  0x080e29b1 in init_video (sh_video=0x84aa478, codecname=0x0, vfm=0x0,
    status=1) at dec_video.c:234
#7  0x080e2d8f in init_best_video_codec (sh_video=0x84aa478,
    video_codec_list=0xbfffd4b4, video_fm_list=0x0) at dec_video.c:280
#8  0x08072a92 in main (argc=2, argv=0xbffff804) at mplayer.c:1568
#9  0x420158d4 in __libc_start_main () from /lib/i686/libc.so.6

I don't remember which CVS version was that where the debug-lines are from,
but as the latest Mplayer rpm (mplayer-0.90-4.20030808.fr) still crashes
in the same spot (fast_memcpy) I assume that part of the code is unchanged:
MPlayer dev-CVS--3.2.2 (C) 2000-2003 MPlayer Team

VIDEO:  MPEG1  320x208  (aspect 1)  24.00 fps  334.8 kbps (41.9 kbyte/s)
Opening audio decoder: [mp3lib] MPEG layer-2, layer-3
MP3lib: init layer2&3 finished, tables done
Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread 1081077376 (LWP 14462)]
0x080bc1a5 in fast_memcpy ()

//	z

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