Problem ending a cut between B-Frames

George

New member
Hello,

I'm having a problem with VideoRedo output files whenever the last cut ends between 2 B-Frames. Here's the story...

I've just started using VideoRedo to clean up and edit downloaded Tivo files before authoring DVDs using Nerovision (v. 4.1.0.15). In most cases, this is working fine (other than lip-sync, which I have to adjust manually). The process that I'm using is TyTool (Mpeg) -> VideoRedo QuickFix -> VideoRedo Edit -> NeroVision. The QuickFix step seems necessary to "stabilise" the file, otherwise navigation in VideoRedo and/or NeroVision becomes unpredicatable.

My objective is to avoid letting Nerovision transcode the files wherever possible, and this seems to work in most cases. Occasionally, however, Nerovision insists on transcoding a file that I've edited with VideoRedo, even if it was quite happy to process the Quickfixed version of that same file without transcoding.

I've tracked this behaviour down to being dependent on the last cut made in the editing process (that is, the rightmost one in the timeline, not the last one made during the editing process). If VideoRedo's last cut goes to the end of the file (trimming off unwanted trailing material), and that cut starts between 2 B-Frames, NeroVision insists on transcoding the file.

It seems as though the final GOP that VideoRedo is generating if it's source ends between two B-Frames is significantly different to the other cases (B-I, I-B, B-P, P-B). If it's relevant, the source file frame sequence is IBBPBBPBBPBBPBBI. It's not clear whether VideoRedo is generating a "bad" mpeg file, or (unlikely as it sounds) NeroVision is failing to interpret a valid mpeg structure.

The obvious workaround is to never cut between B-Frames and to just shift the edit point 1 frame forwards or backwards, but this requires manually checking the final edits each time.

I've got VideoRedo log files showing the activity for 2 edits that differ only by 1 frame, one of which NeroVision likes, the other one it doesn't. I can post the logs here if that would be useful. I also have short(ish) sample files that demonstrate the problem.

Does anyone recognise this problem or have any ideas?

Thanks for your attention...
 
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