[Ffmpeg-devel] libavcodec: possible QPEL decoding bug.

Marius the Mad marius_the_mad
Sun Sep 11 01:29:36 CEST 2005

Hello Marius the Mad.
Saturday, September 10, 2005, 7:38:17 PM, you wrote:

MtM> Do you still want me to provide a sample with QPEL only...?

Just in case, I made another test encode. This time, only QPEL was
enabled (VHQ4 and Trellis also were, but they don't affect the MPEG
feature suite).

The problem with QPEL is still there, although not that visible. This is
with unpatched libavcodec, of course.

Some screenshots:

frame 154 by libavcodec: http://img379.imageshack.us/my.php?image=154a2pp.png
by xvid: http://img380.imageshack.us/my.php?image=154x2az.png

frame 283 (I can't see any difference know) -
by libavcodec: http://img380.imageshack.us/my.php?image=283a1ve.png
by xvid: http://img380.imageshack.us/my.php?image=283x3qj.png

frame 597 by libavcodec: http://img380.imageshack.us/my.php?image=597a1bc.png
by xvid: http://img380.imageshack.us/my.php?image=597x2gz.png

I have to state I used different source preprocessing here - I just don't
have my original script anymore (I modified it later and forgot the
previous state :).

1000 frame clip is available here:

Please let me know if you need more samples. :)

Best regards,
Marius the Mad

1:19:26 AM

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