[XviD-devel] SIGSEGV in interpolate8x8_halfpel_hv_xmm

[Michael Militzer]

Hi Peter,

personally, I have never come across such a problem. Also, I believe no one
ever before reported such a fault. Have you tried to encode some sequence
with the xvid_encraw example encoder, which is included in the XviD source
package? Do you experience the same problems or is the segfault specific
to mp4live? On what processor/hardware were you running XviD btw?

Have you tried on a different system as well? Since the fault seems not
reproduceable and hasn't been reported ever before (afaict), this could also
likely be a hardware fault, e.g. a faulty RAM module. This is also possible
even if you never experienced any similar faults with other software.

bye,
Michael


Quoting Peter Maersk-Moller <peter at maersk-moller.net>:

> Hi
> 
> Im using XViD through mp4live and I noticed that I sometimes gets a
> segmentation fault in interpolate8x8_halfpel_hv_xmm() in
> src/image/x86_asm/interpolate8x8_xmm.asm:337. It runs for seconds or
> minutes and the falls over.
> 
> Here is the output from gdb
> 
> -----------------------------------------------------
> Program received signal SIGSEGV, Segmentation fault.
> [Switching to Thread 16386 (LWP 7351)]
> 0x409692d9 in interpolate8x8_halfpel_hv_xmm ()
>      at ../../src/image/x86_asm/interpolate8x8_xmm.asm:337
> 337     ../../src/image/x86_asm/interpolate8x8_xmm.asm: No such file or
> director
> y.
>          in ../../src/image/x86_asm/interpolate8x8_xmm.asm
> Current language:  auto; currently c
> (gdb) where
> #0  0x409692d9 in interpolate8x8_halfpel_hv_xmm ()
>      at ../../src/image/x86_asm/interpolate8x8_xmm.asm:337
> #1  0x40950b07 in interpolate8x8_switch2 ()
>     from /usr/local/lib/libxvidcore.so.4
> #2  0x7d7d7d7d in ?? ()
> Cannot access memory at address 0x7d7d7d7c
> (gdb)
> ------------------------------------------------------
> 
> I've noticed that the error to to some extend depends on encoder
> resolution and source material. For some resolutions it fails more
> often than with others. It also seems that an anlogue source (V4L
> grabbercard)
> makes it fail more often than when using a digital more cleaner version.
> 
> I noticed the problem in Xvid 1.0.0 and 1.0.1. When possible, I'll test
> it with 1.1 beta.
> 
> Anybody ever seen that problem ?
> 
> Kind regards
> 
> --PMM
> 
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