[FFmpeg-user] Invalid riff index > 256 errors

[Morgan Carr Markell]

When I convert large .MP4 video files (~3 hours long)
to .avi files, using this code:

ffmpeg -i input.MP4 -an -vcodec rawvideo -y output.avi

I get these error messages about once every 30 seconds
of video conversion:

[avi at 0x19ff940] Invalid riff index 257 > 256

and they begin somewhere between 100 minutes and 130 minutes
into the video. The error messages start at different times
for different videos, but the error message start is fairly
consistent when converting the same video again. VLC and ImageJ
can then only open the part of the video converted before the error
messages started occurring.

How can I change the maximum riff index so that this doesn't happen?

Sorry if someone has already asked this question.