Additional Riff Chunk (?) cause AVI playback problems. How to fix it?

[Scallywag]

Occasionally, I get an XviD/DivX AVI that doesn't play well in Quicktime or even VLC. CPU usage spikes, the audio drops out, and/or the video breaks up. When I drop the problematic AVI onto DivX Tool, I get the following warning:

Found a Riff chunk after the first one. . ."

Okay, fine. But what the hell is a "Riff chunk" and why is there second one in the AVI file? And how to I get rid of it or fix the file? "Repairing" the AVI with D-Vision or ffmpegX doesn't fix the playback issues or get rid of the additional Riff chunk.[/quote]

[Cornucopia]

AVI, WAV and RMI (a midi type) are all Windows formats that are based on RIFF containers(Resource Interchange File Format), which use "chunks" as their building blocks. IOW, all riffs are made up of chunks. Most are standardized, some are proprietary (Subs, AR flags, Chapters, Menus, B-frames, Stereoscopic streams). The standardized ones should be read, recognized and acted upon (Playing the file), the proprietary/additional ones are SUPPOSED to be ignored by apps that don't recognize them.

If your app is balking, and throws up a "extra riff chunk" flag, it's either because it's a badly written app that doesn't follow the "don't ask, don't tell" rule, or because the file is corrupted somehow. But that's a different story. Check with more than just those 2 apps.

Scott

>>>>>
edit: you're probably gonna have to use a PC to really diagnose it.