Audio - Video Sync Problem - VirtualDub

[cyberlion]

There are two problems that i face:

1)Think the movie is at 00:25:00 - 25 mins. with ongoing audio track name it X1 when i fast forward to 00:45:00 It should have the audio sequence according to the time. But it plays ongoing track of X1. As such only Video got fast forwarded not the audio with it

2)The audio is 2-3 seconds forward to video.

Actually since i will on my i7 server i won't be able see listen movie since it is remote desktop.

So How can assure - that the audio is similar to video sequence. I can research as much on my PC of your reviews.

I use VirtualDub and encode 700 mb movies.

[cyberlion]

Might anyone bother

[redwudz]

Is there VBR (Variable Bitrate Audio) in the original file? That can cause sync problems at times. What format is the source video, audio and video? VD may not be the best converter for some formats. AVIDemux may be a better choice. What video format are you encoding to? What audio format?

[cyberlion]

There are around 500 movies i have to encode.

1st)
This Movie was unique nothing worked with this if i do full compression mode and compress - not compress it nothing worked. Everytime the audio was 2 seconds forward of video. But when i made it with Direct Stream Copy. It worked. The audio synced with the video.

2)
This Movie i did with no problem Normal Full Processing with audio and video and using lame MP3 compression

3)

This Movie was done with Full Compressing mode both Audio and Video with Lame MP3 compression. But i don't understand the first error box that pops up.

Normally none of my movie gets encoded with direct stream copy - as they do not sync audio with video.

How can i understand of what settings must i use with the chemistry of File information.

[guns1inger]

Open the file in AVI Demux. If you get asked to rebuild the time map, say yes. Re-encode from there.

[cyberlion]

Hi rebuild the time map doesn't come - How to do that. Where is it.

[cyberlion]

Does this pic has to do something with the audio problem. I get this when i put the original AVI.

[redwudz]

No, that's a video error. But you can just crop out of the first frame of the file to get rid of it. It's caused by videos encoded with b-frames, without packed bitstream, and VFW's inability to handle out of order frames. (I think I stole that quote from jagabo )

What I do with VD Mod when I run into MP3 VBR (Variable Bitrate) audio is to save out the audio track with full audio processing as a WAV, then drop that into Audacity and re-encode it to CBR (Constant Bitrate) MP3, then mux it back with the video by adding it in the VDM audio window. Probably better ways to do it, but that works for me. VD doesn't handle VBR audio very well. AVIDemux does it better.

I'm guessing that some programs like VDM can't read the length of VBR audio correctly, and that's where the sync error comes from. VBR audio is commonly (mis)used by coders on the web to save a few bytes on the video filesize, but it often causes problems when re-encoding.

[cyberlion]

I have an audio compression of Lame MP3 can i use that to convert to CBR..

What is audio Stream and full audio process stream

[DarrellS]

What version of Virtualdub are you using? The new versions should handle VBR MP3 without any problems. Just turn off the error message or ignore it.

Why would anyone want to convert 500 movies to 700MB? Maybe a better question is: how did someone aquire 500 full length xvid movie files?

BTW, a two hour movie at 700MB will look like crap.

[cyberlion]

The Pixel quality is like that. Its not 500 but more than 1000.

I am still looking for more.

What is audio Stream and full audio process stream

[redwudz]

What is audio Stream and full audio process stream

When you access the 'Streams>Stream list' in VDM you will see the audio stream(s) listed. If you R click on it, at the bottom of the list is 'Full processing mode'. If you don't select this, the audio stream is just 'passed through' with no changes. Full processing allows you to use the other options, such as 'Compression', etc., which are 'grayed out' otherwise.

If you want to save out the audio as a WAV for further processing, then 'Full processing' is usually required, along with making sure the default compression is set to 'No compression (PCM) If you use 'Direct stream copy' and save as a WAV, you will probably end up with a VBR WAV and still have the same problem.

But, as mentioned, VBM uses a older version of VD and the newer ones may be more suited to your purposes. I use it mostly for short videos that are damaged as I prefer the audio handling over the regular VD.

[cyberlion]

Hmm I want to Mux new 700 MB movies with subtitles and watermarks and i found everything ok. Except audio part goin haywire.

I also get the damn bframe decoder error.

I think direct audio stream is best but bframe decoder needs treatment. I don't want it to be showed for split second when i dub and see the movie. Any solution.

[guns1inger]

If you are re-encoding anyway, use avisynth to load the file and this message will probably not appear. Use a simple script

DirectShowSource("fullpathtofile")

Should be enough