[FFmpeg-user] Warnings when decoding from AVC-Intra

[Christoph Gerstbauer]

I issulated the positions where the warnings appear and made AVI files 
with an H264 streamcopy of the original MXFs. The same decoding errors 
can be reproduced with this AVI files.
The fileprobes can be downloaded here:

https://dl.dropboxusercontent.com/u/26129407/ffmpeg_user_mailing_sample_MXF_AVCI_decoding_problems.zip