Virtualdub: Cutting what you want instead keyframes

[kelman3]

I'm trying to cut out a segment of an avi but I keep getting some video a few seconds before the place where I set the cutting to start.

I searched for this and all I found was that avi files can only be cut using keyframes in virtualdub. DV files have all frames set to keyframes so they don't have this problem.

Is there some way around this?
I'd like to be able to cut out just the portion I want.
No more, no less.

I'm using VirtualdubMod 1.5.4.1

Thanks.

[jimmalenko]

Is there some way around this?

Sure; convert your AVI to DV-AVI

[kelman3]

Doesn't that mean I'll have to deal with full processing mode and hours of encoding?
Or is there a simpler way to do it?

[jimmalenko]

That depends. How long is your source file, and what codec does it use ?

How important is frame-accurate cutting to your process ?

[kelman3]

It's about an hour long and it's xvid.
It's about 4 seconds off at the moment, which is a bit much.

[redwudz]

I had a short file with the same problem and I ended up converting to DV as jimmalenko suggests. If there is a better way, I'd like to know too.

If you look under 'File Information' in VD Mod you will see the number of keyframes. Seems the Xvid codec default is every 300 frames for a keyframe, so it's apparently a common problem. I had 92 out of a total 4345 frames in a five minute video. This was at 15fps. Accurate editing was impossible. I reencoded to 4345 keyframes. This particular video had the keyframes at irregular intervals, just to make it more interesting. It was a slide show/video combination.

[Josef Kneht]

It's about an hour long and it's xvid.
It's about 4 seconds off at the moment, which is a bit much.

From the technical point of view to cut AVI portion frame accurate, one doesn't need to reencode all AVI file. Insted, there is necessary to reencode only GOP part from the current frame to the next K frame.

Though AFAIK VDud doesn't allow users to perform such operations I'm sure there are shareware splitters that do.

Try to google this questions. Your Key Words are: frame accurate AVI splitting or trimming without full transcoding.

Good luck!

[Josef Kneht]

Thoughts...

Well, I think there is a simple but tricky approach

You should trim two parts of AVI. One with transcoding, another with direct stream copy. Then just joint them.

Te first AVI part has to be from a current frame to a GOP end.
The second one is from a GOP end to a frame you need.

Only one thing, is to make sure you will reencode a first part with the same codec type as an initial AVI was coded by.

i.e. if your AVI video is DIV3 you have to transcode it to DIV3 too.

So, I really think it is not so difficult.
Please notify us if you'll succeed 8)

Have fun.