[FFmpeg-devel] mmx2 crash in some xx_qpel_mm2_xx

[GizmoSDK]

17 jan 2009 kl. 23.36 skrev Ramiro Polla:

> On Sat, Jan 17, 2009 at 8:03 PM, GizmoSDK
> <gizmo_video at tooltech-software.com> wrote:
>> 17 jan 2009 kl. 00.47 skrev GizmoSDK:
>>
>>> Hi !
>>>
>>> I am getting a crash with mingw and gcc 4.2.1 in mmx code snippet
>>> named something like ??_qpel_mm2_??
>>>
>>> when decding aac sound and h264 video in decode_audio2 using latest
>>> ffmpeg
>>>
>>> I suspect a compier bug as i dont get it on my mac...
>>>
>>> Any clues or simillar behaviour ?
>>
>>
>>
>> The name of the function is ff_put_cavs_qpel16_mc00_mmx2
>>
>> The code is compiled with -fno-common
>
> Please follow http://ffmpeg.org/bugreports.html and upload a sample
> that crashes. Also tell us what system you're running.
>

Found the issue. The receiving buffer for audio decoding was not  
aligned on Quad Word boundary.
This gave a GPF that was hard to catch using mingw and VS2005.

Anders Mod?n
CTO GizmoSDK