Audio out of sync in AVI file by varying amounts

[smc888]

Hi folks

apologies up front if this is already covered elsewhere. If so, just point me to the topic.

I have an avi file created by uncompressing a set of video archives, parity files inc. This plays fine on the PC using VLC , but not in Windows Media Player v11. I have opened the file in VirtualDub (1.6.19) and it reports that the audio uses VBR of 129kbps +/- 18.1 kbps and this is non-standard. It recommends full audio processing to fix this. When I attempt to comply, it reports that 'no audio decompressor could be found to decompress the source audio format'.

I have experimented with skewing the audio in a direct stream copy, using the VirtualDub, but that only helps for the first few minutes of video.

I tried copying file to a CD using Nero v7 but the same problem exists in playback.

Thanks and regards

Sam

[guns1inger]

You have VBR MP3 audio. Start by installing the LAME ACM MP3 codec so virtualdub can play it back. Load the video into virtualdubmod, and answer No when prompted about VBR audio. Click on Streams -> Stream List. Right-click on the audio track and select Full processing. Right-click again and select Compression. Select Uncompressed PCM, then click OK. Finally, Click on Save WAV and save a new copy.

At this point I would exit virtualdubmod, then start it up again. Load you video, and click on Streams -> Stream List. Click on the audio track and then click on Disable. Click on Add, and select your WAV file created earlier. Click OK, and test for sync. If all is well, click on File -> Save As and create a new AVI file.

Most of the time this will fix the problem. Only once have I had a file whose VBR encoding was so odd that it simply would not sync up, no matter what I did.

[Bjs]

Welcome smc888

To start with , gspot ... use it to determine the internals of the clip and if codecs for decompression are either installed or not .

Never install codecs till it is "known" what is required .

As for virtualdub , its for decoding purpose's , not for actual "full" play back .

While it can perform this function , audio desync during play back will appear .

Use any other program designed for video play back instead .

[smc888]

Hi Gunslinger / Bjs

Thanks to you both, for the welcome and the advice.

Bjs, i just used the Virtualdub tool to try to sync the streams, from advice of a friend who knows more about this than me, but not how to sort out VBR problems! I played back the avi in both VLC and Windows media players, getting an error with Windows mp but it worked fine with th eVLC one. I will try out the gspot s/w you mentioned. Does it come with simple instructions?

Guns, I followed your advice and got to the point of trying to save the new Wav. error was 'Error initializing audio stream decompression - requested conversion not possible; Check to make sure you have the required codec.'

I definitely installed the LAME ACM MP3 codec. Does it matter where it was installed? E.g. should it be in the Virtualdub folder?

Don't know if means anything but the audio stream listed has a tag of 0x0055 which seems to match the LAME MP3 format id. Mind you, I tried selecting a CBR setting from that list and got the same error when I tried to save the wav.

Thanks again for the help folks.

Sam