virtualdub vbr to cbr conversion

[miles6699]

I downloaded a divx video and the audio is at times out of synch. So i loaded the avi into virtualdub where i got an error message. It said : ..improper VBR audio encoding in source avi file...rewrite audio header in CBR...may introduce up to 43680ms skew to the video stream... I continued with a direct stream process of the avi ( since this had helped me with problematic avi in the past) and of course the audio is ahead of the video by a good 3 seconds. I would like to fix the audio cause this is the only glitch in the movie...any suggestions...was i correct in assuming that virtualdub could correct the original synch problem with the proper settings???

[The Edge]

VirtualDub does not like VBR-MP3s as you can see.
Use Nandub instead.

Open the avi and goto File/save wav.
This will extract the full sound track to mp3 but renamed with a *.wav extension.....make sure you CHANGE it to *.mp3
Re-encode this mp3 file to WAV with your favourite sound app and back to CBR MP3.


Edge

[miles6699]

when i convert the video stream to CBR...it will make the audio more stable?? I mean in synch?? What is the difference between CBR and VBR???

[ErL]

I met the same problem.
I use Graphedit to extract the avi audio file to wav (direct showfilters to use are : file source(async) -> avi splitter -> MP layer 3 decoder -> WAV Dest -> file writer

Then I can use Virtual Dub to mix : video in direct stream, audio in Wav-file / choose your compression / direct stream copy.

However, If you transform your VBR to WAV, using Nandub or Graphedit as I do, then mix the wav with VirtualDub, you NEVER get synch problems as the end.

[UncasMS]

have you ever tried virtualdubMOD?

[miles6699]

so here it is....i've coppied the mp3 file out with nandub decompressed it and recompressed it as a CBR...how do i re-interlace it into the original avi...using nandub what are the settings i use?...what happens to the original audio file that is part of the avi now??

[Enchanter]

To mux an audio file with a video file, do the following:

1. Open AVI in nandub
2. Set both Video and Audio tabs to Direct Stream Copy
3. Go to Audio and open the audio file (in this case, the MP3 file)
4. Go to File -> Save as AVI and give a name to the new file

what happens to the original audio file that is part of the avi now??

Since the process involves creating a new file, we will only be concerned with getting ourselves the video information from the original AVI and the audio information from the recompressed MP3.

[The Edge]

Ok, very easy.
1. Open the original avi in NanDub and set the video to DirectStreamCopy.

2. Audio/VBR-MP3 and select the new CBR MP3.

3. File/Save AVI

4. Your DONE!


If the sound is off a few seconds, goto Audio/Interleave and you add/subtract from the delay box.

Good luck.

Edit:
I see Enchanter has faster fingers

Edge

[Enchanter]

Originally posted by The Edge
Edit:
I see Enchanter has faster fingers

The wonders of copy & paste from readily accessed "quick guides."

[miles6699]

well thks for the info...ill let u know how i do...i was told there was an easier way...can you simply convert the VBR to CBR with vdub in the compression selection in the audio tab and run the videp direct stream??? ...ps u say there is a available guide to vdub/nandub here Enchanter??

[Enchanter]

ps u say there is a available guide to vdub/nandub here Enchanter??

My self-written quick guides that reside on my system of course.

[miles6699]

U mean of the 3700 posts, u didnt write out every single one.... I'm appauled...lol

[Enchanter]

Originally posted by miles6699
U mean of the 3700 posts, u didnt write out every single one.... I'm appauled...lol

Read: self-written

That makes up a part of my total number of posts.

[miles6699]

AS always thanks for the info.....The new CBR audio track is much more stable than the original VBR....dunno why anyone would encode a movie that way...the boys at dominion should know better...lol


Anyways thks again...

[Enchanter]

You're welcome.

The new CBR audio track is much more stable than the original VBR....dunno why anyone would encode a movie that way

Don't know why so many people are having trouble with VBR sound tracks. I personally use them, have no problems with and love them.