KVR Audio

MeldaProduction · Post by **MeldaProduction** » Thu Apr 10, 2014 2:33 pm

Hi folks,

I have a really weird issue here. I implemented an AU, using MusicDeviceBase. If the AU has 1 input bus and 1 output bus, it works everywhere. If it has 2 inputs (main and sidechain input), it works too, but not in Digital Performer - it seems working fine, but DP just interprets the output as silence. But when I connect a side-chain everything starts working again. So it must be some AU buffering problem. I do this in the overriden Render method:

- PullInput for all inputs and retrieve the buffers via GetBufferList
- get output buffers via GetBufferList for the single output
- then just render all the stuff from input to output...

The output buffers are definitely not silent, but DP shows nothing... When I connect the sidechain, everything starts working again and the buffers are completely the same!

Any ideas?

Thanks in advance!

Aletheian-Alex · Post by **Aletheian-Alex** » Sun Apr 13, 2014 5:36 am

I don't know if you tried already, but you might want to ask someone like Magic Dave over at MOTUNation. I haven't tried anything like that in Dp recently, but I do recall sidechains acting funny a few versions back when I was trying to get a vocoder working. Sorry that I can't be more help than that.

MeldaProduction · Post by **MeldaProduction** » Sun Apr 13, 2014 8:42 am

Thanks, found it, there is the "silence" flag. Seems that no other host uses it, but DP sets it for all inputs without audio in them, so the sidechain basically made everything seem "silent". I removed the flag and it is working again.

Aletheian-Alex · Post by **Aletheian-Alex** » Sun Apr 13, 2014 5:24 pm

That is useful to know. Was it the 'ioActionFlags' render flag or the 'ioData' buffer parameter?

MeldaProduction · Post by **MeldaProduction** » Sun Apr 13, 2014 5:34 pm

Yes! The ioActionFlags!

How to implement AudioUnit descended from MusicDeviceBase with 2in1out? Digital performer problem...