[FFmpeg-devel] Decoding artifacts with some AVCHD files

[Gerald Dalley]

I have a Canon HG10 camcorder and I'm attempting to decode their AVCHD
content.  Unfortunately, some frames don't seem to be decoding
properly.  As an example, at several points (e.g. starting at about
frame 52) of

 http://people.csail.mit.edu/dalleyg/collaboration/avchd/hg10-pf24-clip2.mts

the bottom field image patches don't seem to be updated quite properly
during a time when the camera moved quickly.  Using the InterVideo
codec, the decoding seems to work fine (unless its always-on
deinterlacer is erasing the mistakes) so I don't think it's a problem
with the HG10's encoder.  Here's a direct link to a cutout frame
demonstrating the problem:

 http://people.csail.mit.edu/dalleyg/collaboration/avchd/decoded/cropped0053bottom.png

I see the problem using the latest clsid build of ffdshow on Windows
from 17 March 2008 and using the latest SVN-built compilation
of and ffmpeg on x64 Linux on 18 March 2008.

I've written up an article that mostly discusses pulldown issues with
the camera (which are not pertinent to this issue), but I also include
this ffmpeg decoding issue.  Search for "Frame Corruption" in

 http://people.csail.mit.edu/dalleyg/collaboration/avchd/readme.html

Has anyone seen this before and/or does anyone know how to fix it?

-- 
--Gerald Dalley
 dalleyg at mit.edu