Why can't Vegas 4 render @ 128 samples(2.9msec)

billybk wrote on 7/17/2003, 9:36 PM
It would be nice to be able to have the option to render @ 128(2.9msec) if necessary.
I am using a UAD-1 with Vegas 4c, and you can't seem to use any Powered Plugins on the main out without getting audio gapping in the rendered stereo wave file. You can use PPI's in the inserts and aux buses with no problem. But, to use PPI's on the main out the UAD-1 needs to be rendered @ 128 samples(2.9msec) to avoid this gapping. In Vegas 4c, for instance, I set it and my Delta ASIO card's DMA buffer size to 128 samples. The UAD-1 initially sync's correctly to the 128 sample size. But....once I start the rendering process, I get an error message from the UAD-1 that says the project app(Vegas 4c) has a different buffer size than 128. Sure enough, I check the UAD-1's sample size meter, and it says a whopping 4410 samples(100msec). Co-incidentally, the Vegas project samples rate is 44,100, strikingly similar. I go ahead and render anyway, and then open the stereo wave file in Sound Forge 6. In the rendered wave file there is a single, humongous, 17,699 sample gap (hole) in the middle of my 3 minute project. A similar thing happens in ACID Pro 4e too(I guess they use a similar audio engine). Except, instead of a 4410 sample buffer size, during the render, it shows a more moderate 512 sample buffer size and the resulting stereo wave file has 3 smaller audio gaps(holes) of about 2000 samples each. This audio gapping occurs whenever the buffer size is larger than 128 samples when rendering. I was getting the same audio gapping in SONAR, but at least in SONAR, I CAN RENDER AT 128 SAMPLES, and the resulting stereo wave file is totally gap free. It seems that to use UAD-1 plugs on the main out, of a DX app, you need to render at 128 samples, or you will get gaps(holes) in the rendered audio. Now you can set Vegas 4 & ACID Pro 4 to a 128 sample buffer setting(as long as your ASIO audio card has this capability), but they will not render at this setting. Could we pretty please, have the option to render audio @ 128 samples(2.9msec) when using Vegas 4 and ACID Pro 4? Or is there a technical reason why this is not feasible? Strange thing is that I can use the PPI's all day long using the Plugin Chainer in SF6, and every render is totally gap free.

How about it SOFO? :)

Billy Buck

P.S. I love my UAD-1 and would like to be able to render it's effects on the mains of Vegas 4 & ACID Pro 4. The alternative right now, is to render, sans UAD-1 plugins on the mains and then import the resulting stereo wave file into SF6 and then use the Plugin Chainer to apply final processing.

Comments

pwppch wrote on 7/17/2003, 10:31 PM
If this is how the UAD-1 works, then it is brain dead. It should NOT have a buffer size requiement like that, but even if it does, it should break up larger buffers that are passed into it into the size that it requires internally. To force this on the host is bogus. This is COMPLETELY doable with in the DX specification for plugins.

Why it behaves differently based upon where the plug is connected makes no sense as buffering through out the signal path is identical.

They need to fix their DX implementation.

If we do provide a work around for this bug in ther DX implementation, it will not be until Vegas/ACID 5.0.

Peter
billybk wrote on 7/18/2003, 5:17 AM
Hey Peter,
Yeah, I do agree that having to do a render @ 128 samples (2.9msec latency) is a bit extreme to me too. I normally like to render at a more reasonable 1024 samples(23.2msec) to conserve native CPU. It only happens when trying to render UAD-1 Powered Plugins (particularly the Pultec EQ and LA2A) on the main out. I don't remember this being a problem with the previous 3.01 version. But, the latest 3.1 update seems to require a really low buffer size when rendering PPI's on the main. Rendering @higher(1024 samples) buffer settings is fine if just using PPI's on inserts and aux buses. For some reason using them on the main out is a problem(gapping) in DX based apps like SONAR, Vegas & ACID Pro. I have been in contact with UA support, and to their credit, they seem to be aware of the problem and they even sent me a replacement beta .dll(that goes into the Windows System 32 Driver folder) to see if it would solve it. Unfortunately, it did not change the gapping behavior. I just happened to try a render @ 128 samples in SONAR 2.2, with PPI's on the main, and was amazed when 7 straight renders were totally gap free. Any higher buffer size resulted in gapping, in the render file, the majority of the time. So I thought I would try it in Vegas & ACID too, but as you know, they will not properly render at this low buffer size. I was just wondering if there was a reason why you cannot not render at 128. No need to playback, just render. Like in SONAR, I can have a real busy project that will pop & crackle @ 128 samples, but the resulting render is pop, crackle and gap free. I was just hoping I could do the same with Vegas & ACID when rendering only.

Thanks for your response,

Billy Buck
pwppch wrote on 7/18/2003, 9:59 AM
Email me directly.

Peter
billybk wrote on 7/18/2003, 10:09 AM
Thanks, I will do that later today.


Billy Buck