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  1. I have a lot of home videos that I want to put on my PC and edit. I have captured them with my adaptec card as Mpeg 2 at several gig. They are interlaced videos.

    I have been using Gnot to convert them down to Xvid with good sucess, but, that's when my problems start.

    I want to edit the videos and my program of choice is Vdub. If I import the original Mpeg 2 file the editing process is fast and fluid. Using the arrow keys for example to frame advance/reverse is instant and accurate with no delays. As I want to use Gnot to convert the file I can't edit the Mpeg in Vdub as it will not save Mpeg out.

    So my idea was to convert and then edit on the smaller file. When I use Gnot I get a good quality file that I import into Vdub to cut and edit but now the time line is jerky as hell and pretty unworkable. If I press left to frame reverse it seems to jump random amounts of frames instead of just one at a time. The same is for frame advance but not as bad.

    Is it down to the settings I am imputting into Gnot or what? I have loaded other avi's into Vdub and they seem to be fine.

    Regards
    Idris
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  2. Always Watching guns1inger's Avatar
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    codecs that apply high compression, such as Divx or Xvid, require a lot more processing power to playback. You are better off editing in mpeg2 (itself a poor editing format), then compressing to Xvid once your editing is done. This will also help preserve quality as it reduces the number of encodes you do.
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  3. Xvid defaults to 300 frames between key frames (unless there's a scene change). In order to seek back one frame it has to go back to the previous key frame and decode every frame from there to the desired frame. Sometimes hundreds of frames. That's why it's so slow. You can make this much less painful by setting Xvid to create key frames at shorter intervals. I usually use 100, but sometimes as few as 30.

    Another problem arises with the use of B VOPs. It sounds like you are having this problem too. When B-VOPs are used VirtualDub often misses by a few frames when you seek backward or forward. Stop using B frames and you won't have that problem. Of course you won't get as much compression either. I never use B-VOPs.

    And I agree with guns1inger, don't edit after converting to Xvid if you can avoid it (except for Direct Stream Copy mode).
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  4. Thanks for the replys.

    I would love to edit first and then compress later. It does seem like a waste of time converting source that I'm only going to dump anyway but that is my biggest problem.

    That fact that Vdub won't let you save off edited Mpeg without you converting it to avi is a pain. I like the configurability (if that's a real word!) of Gnot to fine tune the compression process and I have never had any real sucess compressing directly from Vdub. It always seems to crash on me.

    I must admit I am surprised that Vdub does not have the option to direct stream Mpeg2. I have tried other mpeg editors which do not recompress but because my source is interlaced they all seem to muck up the output when saved.

    Cheers
    Idris
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