VirtualDub lying during Audio conversion...

[CraigJohnson]

VirtualDub 1.5.10 is giving me grief when I try to split some WAVs out of the .AVI files I have – note that this only happens on a very few files, and these always have – in File Information – an audio stream compression value of “Unknown (tag 0055)”. Trying to make a WAV out of these files always gives:-

“Error initializing audio stream decompression: The requested conversion is not possible. Check to make sure you have the required codec.”

Now, I’ve used both AVICODEC and GSPOT, both of which tell me the AVI files have a perfectly valid MPEG-1 Layer-3 audio encoding, and GSPOT even tells me that I have four valid codecs installed to read this…except VirtualDub doesn’t suss this.

It’s 2 channel, not 5, so not that AC3 problem, and although I can use AVI2WAV to get a wave file, it is horribly unsynchronised with the video (presumably because the original is sampled at 48kHz and AVI2WAV keeps this, whilst VirtualDub lets one change it to 44.1KHz).

As I say, this only occurs on a very few .AVIs, but it’s really annoying that this is happening…why does VirtualDub not recognise the codec, when AVICODEC and GSPOT do? What can I do about it?

Cheers,
Craig

[sfheath]

Are you using VirtualDubMod 1.5.10?
What Operating system are you? It sounds like you don't have an mp3 codec which is in contradiction to what G-Spot is saying

[ormonde]

"this only occurs on a very few .AVIs"

Are you able to successfully "Play" the AVIs in a software-based player?

[setarip]

I'm guessing that these "very few .AVIs" are files that you haven't created - and are either fake files or corrupted (download) files...

[CraigJohnson]

Some answers:-

I've tried VirtualDub 1.5.10, VirtualDub 1.6.5 and VirtualDubMod 1.5.10.1 - same thing in all three.

Yes, these play in WMP 10 and in Creative MediaSource, without a single problem...right to the end (audio matches fine).

And I'm on XP with SP2.

Cheers,
Craig.

[ormonde]

"Yes, these play in WMP 10 and in Creative MediaSource, without a single problem...right to the end (audio matches fine)."

As an experiment, try "Converting" one of the AVIs to mpeg, and see if you can demux the audio stream.

[CraigJohnson]

OK, I've used TMPGEnc using the AVI as the input for both Video and Audio, and hit the DeMux button - now have a .m1v and a .mp2 file for it. Now what though? Rerun TMPGEnc to combine them back again?

Could I be faced witha corrupt file - maybe just one bit or something is wrong, allowing it to play ok but just not be processed?

[ormonde]

"Now what though?"

What is it exactly that you are trying to accomplish? Will the audio stream (mp2) play OK independently?

[sfheath]

If you have an mp2 now, does this help?

http://www.radio-now.co.uk/mp2_to_wav_conversion.htm

[CraigJohnson]

Originally posted by ormonde
"Now what though?"

What is it exactly that you are trying to accomplish? Will the audio stream (mp2) play OK independently?

I should've made this clear at the outset....

What I'm trying to do, is convert these AVIs into VideoCDs - the process I've been following (with 95% success rate, I would say), is to use VirtualDub to split the audio off into a WAV file, then TMPGEnc to create an MPG from the AVI and the split WAV, and then VCDEasy to burn the disc. All works well except for these few, which VirtualDub can't do the split - and yet if I split with AVI2WAV, for example, after TMPGEnc runs the audio is out of sync with the video.

So the audio plays ok - the video plays ok - it's just doing it via VirtualDub means it syncs up, otherwise it doesn't...

[CraigJohnson]

sfheath, yeah that's good to make it a WAV, but once again the sync still mucks up on the final merge...is there a good alternative to VirtualDub that does much the same thing, just better than AVI2WAV?

[ormonde]

"TMPGEnc runs the audio is out of sync with the video."

In TMPGEnc, Click the "Setting" button at the bottom of the main dialog. Click on the "Advanced" tab and double-click on "Source Range". In that dialog at the bottom, there is an "Audio Gap Correct" window that will allow you to correct the audio by using a plus or minus value.

[setarip]

Just wondering if these few .AVIs mighnt' use the infrequently applied .MP3Pro audio format...