Edit program that cuts exactly with like divx, xvid, ...?

[Ghtpua]

Hi,

I really like virtuldub and I captured a movie with the default codec that studio pinnacle offers and it cut perfect with virtualdub, however, it took 80 gigs on my hard drive for 3 hours about. I want to capture with divx, xvid, ... instead. What editing program that will cut commericals exactly where you want them with divx, xvid, ...? Please an thank you!

[redwudz]

This is my understanding: When you use a highly compressed format like Divx, it is difficult to get exact edits. When you open in VirtualDub, look in 'File Information' under 'File.' Look for 'Number of key frames' VS 'Length' in frames. VirtualDub and most editors can only cut on keyframes. Divx may only have a keyframe every 300 frames, so that is your accuracy.

Unless you use a codec like DV where every frame is a keyframe, you can't cut on the exact frame you want and save it with 'Direct stream copy'. You can cut where you want, but you will have to re-encode it, and there will be some lose in quality. A keyframe has the complete frame and frame info, the others just show the changes from the keyframe. They are not complete frames, so all the necessary information is not there. Re-encoding will fix that. That's a problem with using a highly compressed video and trying to edit it.

[Ghtpua]

Hi,

Virtualdub will not cut out the comericals exact then. What program will cut out the comericals exact using divx, xvid, ...? Please and thank you!

[redwudz]

It will cut on the exact frame if you re-encode the video. AFAIK, all editors will have the same problem. It's not the editor, it's a problem with the video or codec used. Divx was designed for high compression to make files more compact, not for editing. If you need to do extensive editing, when you encode, you should set your codec to use more keyframes, such as one per second, if that is the accuracy desired. Xvid or Divx can do that. In the codec, click 'advanced' and set the 'I' frame rate from 300 to 30. That should give you a keyframe about every second with NTSC video. It will increase the size slightly. But you should be able to use 'Direct stream copy' then and not have to re-encode.

There are probably some experts out there that may correct me, but that's my understanding of editing with Divx or Xvid.

Here's a article on keyframes: http://nickyguides.digital-digest.com/keyframes.htm There are also some good guides on that site.

[Ghtpua]

Hi,

Thanks for helping me I really appreciate it! I do not want to have to converet because that takes more time. Will windows xp media center cut exactly where you want with divx? How about nero? Or something else?

[redwudz]

For simple cut and paste AVI editing VirtualDub is one of the best. As I said, it's not the editors fault, it's the video. They will all have to to do some re-encoding if you are not able to cut on the keyframes. In the future, just change the keyframe rate down to 30 or so when you capture and you will have much easier editing with Divx. For now, you will have to edit and re-encode them if you want more accurate cuts.

That article I linked to explains the problem. Only the keyframes contain the whole picture. If you cut in between, you will have a section of corrupted video until the next keyframe. If the keyframes are 300 frames apart, at 30 frames per second, you would only be able to cut in 10 second intervals. (300 frames/30fps= a keyframe every 10 seconds, If my math is correct. ) Divx and Xvid by default set the keyframe at 300 frames intervals. Of course they are not that evenly spaced. In faster action areas, they may be a closer together. That's the price you pay for using a highly compressed format: Poor editing ability. In a codec like DV, every frame is a keyframe, so you can cut with an accuracy of one individual frame. But it takes 13GB storage space for an hour of video.

If you have the hard drive space use a codec like HuffyUV or PicVideo to capture. It is much easier to edit.

[jagabo]

I don't know why nobody has written an editor like Womble's (MPEG2 editor) for Divx files.

You can use VirtualDub to cut wherever you want and only reencode near the cuts. But you have to do a lot of manual work. You save some sections with Direct Stream Copy, and reencode other small sections. Then append them all together when you're done.


Suppose you have the following video:

A-------B-----1----C-------D---2---E-----F------

The letters are keyframes. The hyphens are not keyframes. You want to remove the section from 1 to 2:

Save the section from A to 1 with Direct Stream Copy.

Reencode the section from 2 to just before E.

Save the section from E to the end with Direct Stream Copy.

Then join the three sections together:

(A-------B-----) + (rrr) + (E-----F------)

(rrr) is the reencoded section.