VV Fails to render audio

farss wrote on 7/30/2003, 8:42 AM
This has happened to me twice now, the first time I just thought it was finger trouble but now I'm not so certain.

Its only happened when I'm rendering very long programs and when I'm transcoding.

The first time the program was 2:30:00 long and I was going from PAL to NSTC. I got (after many hours!) an AVI file with an empty audio track. At the time I thought myself an idiot for turning the audio off but later I realised if I done that there wouldn't even be an audio track. Anyways I fixed it without a total re-render, I just rendered out the audio to WAV and bought that into the NTSC AVI and all was well. Due credit to VV there, at no point did it lose sync despite changing the frame rate.

So tonight after 20 hours of hard work VV just finished converting 2 hours of lo res WMV to full res PAL. Shock horror. Again empty audio track!

Go back to original WMV file, render out audio to WAV and audio is there!

This time I will have to sync it up because I'd cut some video off at the beginning but that shouldn't be too hard.

I think and its just a guess, that this may only happen IF I start to render out before VV has finished building its audio peak file.

If I've got time I'll try some experiments but at render times around 20 hours and big demands on the machine that's pretty difficult.

Comments

mikkie wrote on 7/30/2003, 9:11 AM
Yep... *@#!~+*!!! happens.

Happens a bit more often rendering just the audio as a direct stream. Used to be able to tell because render speed was too fast, but that was with version 3.

When it happens with a WMV file, easiest solution is to just re-render the audio only to wma. Then use the MS utility (comes with the stand alone encoder) to combine the rendered video and re-rendered audio.

Problem is when you forget to check the rendered file - and have to go back and get source, all 6 channels of it! Not one I'll forget for a while.

IF it's a clue to sorting out, usually happens after more intense editing, restarting Vegas will usually fix it, though with Version 3 in 98 SE a reboot was necessary. Also seems to happen a bit more often if I open a bunch of new proj in a row, trying stuff out.

Best luck
farss wrote on 7/30/2003, 9:34 AM
mikkie,
thanks a bundle, I mean you haven't fixed it but at least I know I'm not loosing my marbles.

I just went back to the source and rendered out the audio to a WAV, substituted that for the empty track in the AVI, synced it up and all is well.

Bit of a worry though if this was a known bug in V3 and we're at V4.00c and its till not fixed eh.

It shouldn't be that hard to trap it, some form of dead man timer should pick it up, count the number of times it's written zero as the audio level, when that gets to a very big number have a look see what's on the source track.

Still that's the problem with complex software, very few people are affected by this no doubt and if that was the only reason for parting with money for an upgrade I doubt if I'd be paying up, yet developers have to eat too.

simojo wrote on 7/30/2003, 12:12 PM
The same thing happened to me a few weeks ago. But I was in such a hurry I'm not exactly sure what I did to get it to finally work. So this is a sympathy reply, not a solution reply.

I recall the problem was limited just to WMV formats, so I blame Microsoft. I may be wrong. I did find that if I let the render go a few minutes, I could go to the hard drive and play the begining portion of the file rendered so far. If there was no audio, it showed up and I could cancel the render and start over. I tried this hack after waiting/wasting hours for the render to finish and getting jack.

Love to hear the solution if there is one....
BillyBoy wrote on 7/30/2003, 2:01 PM
The likely reason is you used the WRONG template. I've done it. Some templates are video only. If you rush you can easily pick the wrong one. Also it is easy to mute one or more tracks or have one set to solo.

I'm not saying there may not be a 'bug', simply I haven't seen it and did catch myself a couple times using the wrong template.

farss wrote on 7/30/2003, 3:33 PM
Hi BillBoy,
how are you going?

Anyway that was my initial reaction as well, a couple of times I render AVIs with no audio so I just thought I'd done something dumb like foregting to check it was not turned off.

But if you turn audio off you get an AVI file with no audio track. I've been getting an audio track with no audio in it. That kind of leaves the muted track as being the only possibility But this is not something I'm editing, typicaly I'm rendering from a WMV file to a AVI file or doing PAL to NTSC.

Anyway from what mikkie is saying this has been a known problem for some time going back to version 3
simojo wrote on 7/30/2003, 4:39 PM
In my case, it was not due to having the wrong template with no audio. I rendered out to a variety of custom audio and video bit/sample rates.