Need Help Synching Audio

[Lord_Anselhelm]

Hi there

I'll try and explain the problem as best I can. Hopefully all the correct information will be in there. I haven't done enough video encoding to become adept at it, so I'm in the category of "newb with some knowledge" in here.

I recently bought my mum a Kiss DP-1000, which is a DVD player capable of playing xvid and divx files with ac3, ogg or mp3 encoding. Though it's good, it started having audio synchronisation issues with certain files, so I went back and had a look at the files I'd put on to cd.

Each of the files has had its audio encoded using VBR MP3. If I load these up in VirtualDub, the program detects "improper VBR audio encoding in the source AVI file". Although these files play fine on a top speed computer, it seems that the Kiss player is not fast enough to deal with this kind of encoding on the fly, which leads to audio-visual desynchronisation, normally with the audio running ahead.

I need to recode the audio of these files (copying the video directly using the direct stream function of virtualdub), which I plan to do by dumping the audio into a wav file and reconverting that to 128kbps MP3 audio in the reconverted file. However, I first need a program or exact method to determine the audio delay within these files, as otherwise it's nothing better than a guess game and I am NO good at guessing or deducing: I need a program to simply show me here.

I'm really hoping that someone here can help me out, otherwise I'm screwed. I bought my mum this present so she could watch the files I was sending her, but she can't watch them if the audio is all screwed up, and I do know for a fact now that it is the VBR MP3 causing the problem, as the processor on the unit is only 198MHz.

PLEASE HELP ME!!!

[ormonde]

Refer to the following link for some helpful information:

http://nickyguides.digital-digest.com/audio-synch.htm

Scroll down to "PART 2: Fixing Audio Displacement"

[Lord_Anselhelm]

It's a start, but it will still involve a lot of manual work, and I'm not lying when I say I'm not very good at lip synching videos. I'm not complaining at the help though by any means, and I thank you for pointing me at least to something which will help me in the end, but I'm really confused as to why nobody seems to know a program which can visualise the video and audio streams and show their alignment. It seems like an essential tool for re-encoding I would have thought.

[ormonde]

"I'm really confused as to why nobody seems to know a program which can visualise the video and audio streams and show their alignment."

Honestly, I don't know of a particular program that will do this...it's mostly been based on trial and error.

[setarip]

Converting .AVIs with VBR-MP3 Audio

Simply use NanDub or VirtualDubMOD (Different than standard VirtualDub), to save the audio stream as an Uncompressed PCM (WAV) file as follows:
1) Load your original .AVI into NanDub

2)Set "Video" to "Direct Stream Copy"

3) Set "Audio" to "Full Processing Mode" (NanDub only -For VirtualDubMOD>"Streams>"Stream list">>rightclick on the listed audiostream and then select "Full Processing Mode")
From the "Audio" dropdown menu, select "Compression" and choose "No compression(PCM)" (NanDub only - For VirtualDubMOD>"Streams>"Stream list">>rightclick on the listed audiostream and then select "Compression" and choose "No compression(PCM)")

4) From the "File" dropdown menu, select "Save WAV" (In VirtualDubMOD, "Save WAV" is located under the "Streams" drodpown menu) (Enter a new filename with a ".WAV" extender).Click on "OK"

5) Then save the .AVI as a silent .AVI (NanDub - set "Audio" to "No audio" after you've saved the WAV file. - For VirtualDubMOD>"Streams>"Stream list">>click on the listed audiostream and then select "Disable").


Then close NanDub and restart it
Set "Audio" to "No audio" (Not necessary under VirtualDubMOD)
Load your silent .AVI
Set "Video" to "Direct Stream Copy"
Under "Audio" click on "WAV Audio" and load your .WAV (In VirtualDubMOD, Streams>>Add)
Set "Audio" to "Full Processing Mode" (In VirtualDubMOD, Streams>>Rightclick on the listed audiostream, click on "Direct Stream Copy")
From the "Audio" (In VirtualDubMOD, "Streams") dropdown menu, select "Compression" (In VirtualDubMOD, rightclick on the listed audiostream, click on "Compression") and choose the appropriate .MP3 settings. Click on "OK"
From the "File" dropdown menu, select "Save as AVI" (In VirtualDubMOD, "Save as") and save your file with a new filename.

[Lord_Anselhelm]

As thankful as I am for you taking the time to write that description, I do already know how to convert the VBR audio into an uncompressed wav and then back into CBR MP3 audio in an avi file, though VirtualDubMod does seem to do more processsing work than the normal VirtualDub, which is nice.

Unfortunately though, it does not solve my synching issues


Is there HONESTLY no program which shows you when the audio starts up in relation to the video stream??? How hard can it be to program such a thing??? It would solve my problem in an instant and wouldn't require that I keep tinkering around trying to find the exact audio/video matchup.



EDIT:

AHA! Finally! After many fruitless hours of searching, I finally got lucky. There's a tool called AVI Info which can detect the audio delay in a file. This (combined with the enhanced audio synching power of VirtualDubMod) has finally given me a method of re-coding the VBR audio in a file to CBR whilst maintaining the correct audio synch!!!

Thank you for all your help anyway

Please tell the people about AVI Info for their recalculating audio needs with AVI files.

[ormonde]

"Thank you for all your help anyway"

Glad to hear that you have resolved your problem...

[Lord_Anselhelm]

Unfortunately I soon after found that AVI Info wasn't all it was cracked up to be. While it can detect the audio delay in some files, it's not very consistent, and doesn't detect it in 99% of my files.

However, rather than burden you guys again, I decided to try my luck again and see if I could find a program like this which actually works. And I got lucky. I found a program called AVI Mux GUI, which you drag and drop avi files into, and it gives you correct info about the file.

This is of REAL good use to people who are not good at working out the necessary audio delay and who just want a program to show them what the audio is being delay by. The project is on this webpage here:

http://www-user.tu-chemnitz.de/~noe/Video-Zeug/AVIMux%20GUI/index-eng.html