In some case for aac in AVI, avidec extracts wrong PTS value.
(www.ffmpeg.org/trac/ffmpeg/ticket/1755)

I found additional case(ss=4096) and add condition.

Problematic file link : https://docs.google.com/open?id=0B6r7ZfWFIypCOTdZQUtGVEdJUUESigned-off-by: Michael Niedermayer <michaelni@gmx.at>