[Ffmpeg-devel] Two ASF related bugs and fixes

[emild at cs.technion.ac.il]

Hello,

I have found two bugs related to ffmpeg's ASF file format.

1) The first bug has to do with the ASF writer. The problem is caused by the
fact that the size of the padding is not adjusted to include the size of
the padding length field. This causes the last byte of the payload to be
overwritten with zeroes before it is written to disk, thus yielding an invalid
bitstream.
mplayer and even ffmpeg complain when such streams are passed to them.

I have put an input file which illustrates the problem at:

ftp://ftp.mplayerhq.hu/MPlayer/incoming/ASF_PROBLEM/WRITER/IN/Philips_qcif.mp4

and the resulting output at:

ftp://ftp.mplayerhq.hu/MPlayer/incoming/ASF_PROBLEM/WRITER/OUT/buggy_Philips_qcif.mp4.asf

The command line used was:

ffmpeg -i Philips_qcif.mp4 -r 15 -b 64 -an -s 176x144 -vcodec wmv1
buggy_Philips_qcif.mp4.asf


For example this is what mplayer has to say about the resulting output file: