mpegvideoparse: fix timestamps

Submitted by Matej @Knopp

Link to original bug (#705066)

Description

Created attachment 250353
Filter that fixes mpeg timestamps

Mpegvideoparse currently doesn't do anything about fixing broken / missing timestamps. This affects playback for many files in my case. I'm currently using custom filter after mpegvideoparse to do this, but perhaps the functionality should be added to the parser?

If someone could look at the code and confirm I can provide a patch. Although unlike my filter mpegvideoparser probably can't get away with throwing away D frames so this will need to be addressed. Does anyone have a stream with D frames?

Attachment 250353, "Filter that fixes mpeg timestamps":
MpegTimestampParser.zip