Changing the FPS of a video segment?

[Pearnamer]

I was taking advantage of a newer, shiner, and larger than 1 GB hard disk, by playing with the video capture abilities of my RR-G, and walked off while it was capturing three hours of video.


Now, since I'm still running Windows 95, I ran into the 2G file size limit several times, and as a result, have several files sitting around that I'd like to compress and link up. The problem is that [as has been mentioned on this forum in the past] the Matrox PVCR isn't known for having the most ironclad control of frame rate.

In the middle of everything, I have a segment that's at 30.017 FPS instead of 29.970 FPS like all of the other segments.

This gives VirtualDub no end of problems for pasting video segments together. Now, both VirtualDub and Ulead MediaStudio will let me change the frame rate of the video, but then it immediately loses synch with the audio (being about a minute off at the end of a half hour).. MediaStudio allows me to change the speed of an audio track (imported separately from a video track), but only in whole number percentages, so the closest that gets is about 40 seconds off.


Any suggestions [besides to use something that has a tighter control on framerate for future captures] on what I can do to change both the video FPS and the audio of a single video segment down a pesky .047 FPS so I can string them all together?

[Dr Mordrid]

Capture with AVI_IO. It has active features for locking the frame rate to 29.970 and keeping it all in synch, even if there are frame drops. VirtualDUB doesn't do this and neither does PC-VCR.

Dr. Mordrid

[Pearnamer]

Oh yes, in the future, after I've tried it out, I'm sure that I shall sing the praises of capturing via AVI_IO.


However, for the current situation, is there anything I can do with the video I've already captured to re-factor it into the correct speed?

[This message has been edited by Pearnamer (edited 16 May 2001).]

[Dr Mordrid]

If you have MSPro you can try using its frame rate conversion tool. It's at File/Convert/Frame Rate. VirtualDUB can also do this.

Neither of these, however, can make up for loss of synch due to dropped frames. That has to be done at capture time by a program like AVI_IO. It automatically copies the previous frame into the empty slot when a drop is detected.

Doing this in post presents the issue of detecting where drops ocurred after the fact. Not easy. Also, adjusting frame rates in post can present the synch issues you have already experienced.

Dr. Mordrid


[This message has been edited by Dr Mordrid (edited 17 May 2001).]