- It is now the responsibility of each video provider to provide a list of keyframe positions and (if it can) timecodes.
- The ffmpeg video provider now indexes files before opening them and does no longer rely on stream->duration to determine the number of frames. Fixes opening of MKV files, but it does not (currently) open timecodes automatically and reported keyframe positions seem way off. Status of frame-accuracy with MKV files unknown but it may very well work.
- Modified the way the ffmpeg video provider seeks (inspired by code from Myrsloik's ffmpegsource). Should no longer lose the first frame and should also no longer be frame-inaccurate, at least not with AVI.
- DirectShow video provider may or may not be completely broken, not tested.
Originally committed to SVN as r2252.
