Can't cut 4 frames out of AVI file

[DRP]

I'm trying to cut 4 frames from an AVI file but VDubMod won't do it for me. I mark the beginning and end frames and then cut that selected portion and sure enough it disappears, but then when I try to resave the file as a Direct Stream Copy, they come back again in the final product.

I've tried many times to do it but nothing with cut these 4 frames for me. The beginning frame is a keyframe and that cut happens where it should. The end frame however is not a keyframe and that cut is the one that isn't happening. How can I cut at a non-keyframe or alternatively insert a keyframe so I can cut at that point?

[Firk99]

I think that the only way to achive this is by decompressing your file, cut the unwanted frames, and finally recode your file. A lot of work and possible some quality loss.

[junkmalle]

You can only cut at key frames with Direct Stream Copy. This makes sense because non-key frames don't encode the full picture, only the differences from the frame before.

If you can live with cutting out the whole section you can use Shift + the arrow keys to move the previous/next frames to mark them, then cut.

If you want to loose as little as possible (and reencode as little as possible), mark from the start to the key frame just before area you want to remove. Save that with Direct Stream Copy as Part1.avi. Then mark from the first keyframe after the part you want to cut to the end of the file. Save as Part3.avi. Then mark from the keyframe before the part you want to cut, to the keyframe after the part you want to cut and switch to Full Processing mode. Delete the four frames you want to delete. Be sure to use the same compression codec. Save the section as Part2.avi. Finally, Open Part1.avi, append Part2.avi and Part3.avi, and save with Direct Stream Copy as Full.avi.

[DRP]

Thanks for that advice. That's exactly what I shall do now. Weird that the second cut point isn't a keyframe. It *is* a scene change so I would've though it would have needed to be a keyframe.

There's a scene change (key frame), 4 frames, then another scene change (without key frame). When it plays, there's just a very quick flicker of the different scene as you watch - not surprisingly being only 4 frames shown at 25fps speed.

It's reminiscent of those episodes of The Young Ones when they'd insert 1 or 2 frames of something completely unrelated to the story into the middle of the episode.

[DRP]

One more question if I may:

The codec used is DivX v3 MPEG-4 (Low-Motion) which makes things easy as it has so few configurable options, but with regard the bitrate, how can I set it to be the same as the other two parts I direct stream copied out?

I've used AVIcodec to find out the other two parts have a bitrate of 949kbps - is that a VBR bitrate or is it CBR with this codec? Do I just set the new bitrate at that value and let it rip?

[junkmalle]

It doesn't matter what bitrate you choose. In all likelyhood the source file is variable bitrate. Whatever bitrate you use will just look like more variation. And if the source is constant bitrate the new portion will just look like a variable bitrate section. So, unless you have some external reason to have a specific bitrate, just pick a bitrate that gives you the quality you want.