Audio problems with VirtualDubMod

Frodo345 · Post by **Frodo345** » Sat Feb 25, 2006 1:52 am

Okay - I searched through the first 6-7 pages of all the likely forums, so either (1) I'm blind, (2) Nobody else has encountered this problem, or (3) I'm t3h n00b.

Anyway - I'm using VirtualDubMod, attempting to stream a mp3 into an avi (previously an ogm, but I changed it using a demuxer for other reasons). When I stick the mp3 into the stream, it'll delete itself as I delete various portions of the avi - that is, if I then delete frames 100-400, then the music that would play at that point will simply not be there.
Of course, being the master video-editor I am (just started a couple days ago), I thought it would change things if I were to delete the video portions before I added the stream (and before I save it as a different file - I don't want to go through the problems with compressing-decompressing 30 times, or continuously saving decompressed versions). But it changed nothing, when I played the sequence again, it simply removed the sections in the audio again.

Is there some feature in VirtualDubMod I'm missing to make it so I don't delete sections of the audio?... or any other way to solve it - I'm not picky.

Anyway, time for bed, I'll check back tomorrow afternoon.

Mo

Qyot27 · Post by **Qyot27** » Sat Feb 25, 2006 3:03 am

Cut the portions out of the video, make sure that Direct Stream Copy is selected (it's in the Video menu), save the file, open the new file, add the audio, make sure Direct Stream Copy is still selected, and save to another new file. That one will have both the video and audio.

Direct Stream Copy basically takes the existing data stream and pipes it through to another file. The only thing to remember is that you can only cut on keyframes. To know whether you're on a keyframe or not, just hit Shift and the right or left arrow key while you're in VDubMod. Keyframes in DivX or XviD files are usually spaced out 50-300 frames apart or so, whereas with HuffYUV or Lagarith it's required that every frame is a keyframe. So that warning only really applies for DivX or XviD. If you're working with HuffYUV or Lagarith, you can cut whereever you like.

Frodo345 · Post by **Frodo345** » Sat Feb 25, 2006 10:56 am

Well... that sort of solves it - how would fine editing be possible then?

It's a dismal future if I can only remove huge chunks of the video.

Is the only way to do fine editing without a huge loss of data through successive compressions/recompressions to rip it again in a less "lossy" codec?

Scintilla · Post by **Scintilla** » Sat Feb 25, 2006 11:09 am

Frodo345 wrote:Is the only way to do fine editing without a huge loss of data through successive compressions/recompressions to rip it again in a less "lossy" codec?

Well, you could take the AVI you direct stream copied to and serve that with AVISynth's <b>AVISource()</b> command, which should fix most of the issues associated with editing such lossy files. More on that here:
http://www.amvwiki.org/index.php/DivX_Editing

Frodo345 · Post by **Frodo345** » Sat Feb 25, 2006 1:13 pm

Thanks - I was sort of hoping that I could just use VirtualDubMod to directly fix it, but I guess this just means that I'm going to have to learn some more about AviSynth.