Trying to cut with VirtualDub but get this error?

[J-E-T-S]

AVI: Variable bitrate (VBR) audio detected. VBR audio in AVI is
non-standard and you may encounter sync errors up to 43680ms when
attempting to extract WAV files or processing the audio in Direct Stream
Copy mode. Full Processing mode is recommended to decompress or recompress
the audio. (bitrate: 151.5 ± 32.3 kbps)

I am trying to cut out a scene from an avi file but when I load it with VirtualDub, I get an error like the one above. If I continue the operation, I get an avi file with audio sync problems.

Is VirtualDub the tool to use for this task or is there a better tool that can overcome this error?

[towerblocks]

Try using nandub instead.

[FulciLives]

This error is due to VBR MP3 audio. There are several ways to "deal" with this but I will give you my preferred way.

1.) Load the AVI into GOLDWAVE.
2.) Save the audio file as a 16-bit 48k 2 channel Stereo PCM WAV audio file.
3.) Load the AVI into VirtualDubMod
4.) Go to the STREAMS LIST and X-out the VBR MP3
5.) While still in the STREAMS LIST load the PCM WAV audio file that you created/saved out of Goldwave.
6.) You are now ready to edit.

BTW the same thing can be done with AviSynth. It would look like this:

vid=AviSource("C:\VIDEOS\myvideo.avi", false)
aud=WavSource("C:\VIDEOS\myvideo.wav")
AudioDub(vid,aud)

Now load this AviSynth file into VirtualDubMod. Go ahead and do your editing. When you are done editing go to the SCRIPT EDITOR and select "Import Frameset as Trims" and put the editing info after the AudioDub line.

You will end up with something like this:

vid=AviSource("C:\VIDEOS\myvideo.avi", false)
aud=WavSource("C:\VIDEOS\myvideo.wav")
AudioDub(vid,aud)
Trim(1181,10542) ++ Trim(12473,33484) ++ Trim(38689,60059) ++ Trim(66864,98725)

Now make sure you save the AviSynth script after doing the "Import Frameset as Trims" and you can now go ahead and load the AviSynth script into your encoder without having to go through VirtualDubMod or making an intermediate copy etc.

- John "FulciLives" Coleman

[manono]

Do you really do all that when you just want to cut a scene out of an AVI, FulciLives?

Try using nandub instead.

Or use VDubMod and answer "No" to the VBR question.

[FulciLives]

Do you really do all that when you just want to cut a scene out of an AVI, FulciLives?

Try using nandub instead.

Or use VDubMod and answer "No" to the VBR question.

Well the method I posted above (using AviSynth with VirtualDubMod for editing import) is how I would do it IF I was trying to get from AVI to MPEG-2 for creating a DVD Video.

In fact I would do it this way if I was going to re-convert to ... whatever ... be it another AVI file or whatever. To be honest though I've never tried to edit a MPEG-4 AVI and do a direct stream copy on what was left. Is that even possible? I mean sure it is but don't you have to edit on "I" frames and don't "I" frames only happen like once every 300 frames or some such nonesense with MPEG-4 files? So if you want to do any "exact" editing you will have to re-encode anyways so might as well use my AviSynth example.

I dunno.

I am assuming the source is MPEG-4 if it has VBR MP3 audio.

I always encode my MPEG-4 files with AC-3 when available or CBR MP3 ... never VBR MP3.

- John "FulciLives" Coleman

[J-E-T-S]

Thank you. I tried Nandub and it's what I need. One question though: does saving the avi segment using "Direct Stream Copy" degrades the quality of the output file?

[jagabo]

I agree with manono. VirtualDubMod can very often handle the file with no problems if you answer "no" to the VBR MP3 question.

[J-E-T-S]

One other question, in addition to the Direct Stream Processing question, is....sometimes Nandub will give me the following error after I open some avi files:

error fetching frame X: VideoSourceAVI error: unspecified error (-100)

What is this and how do I fix it?

UPDATE: I found the answer. I changed the FourCC codec information using the AVI FourCC Code Changer found here. I loaded the avi file with this code changing program, and I make sure that both boxes show the same four letter code. A lowercase xvid is not the same as XVID. Both have to be either lowercased or capitalized. Apply the change, load the avi file up with Nandub and the error will go away.

That's for any other newbie who runs into this problem.

[jagabo]

That must be some peculiarity with Nandub or the MPEG4 decoder you're using. Normally the "FourCC Description Code" is lower case "xvid" and the "FourCC Used Codec" is upper case "XVID".

[manono]

One question though: does saving the avi segment using "Direct Stream Copy" degrades the quality of the output file?

No. Anything Direct Stream Copied gives you the same as the original.

[J-E-T-S]

Thanks to everyone who replied. This problem of mine is solved.