Rendering bug

[harisonzamperla]

So I've noticed that sometimes with multitrack latency set at the lowest setting in conjunction with iaa there are very crackling glitches in audio mixdown, altispace in particular is prone to this. Setting the latency higher before rendering seems to fix this. I was thinking that it would make sense to have the latency automatically set itself temporarily on high while rendering since theres no need for monitoring while rendering. Thanks

[pwnified]

Indeed, the amount per buffer rendered from the plugin for mixdown, is independent of the coreaudio playback/recording buffer size. Currently it asks the plugin for 1024 samples per iteration during mixdown. There might be something else going on here, related to how reliable the plugins are at switching buffer sizes. How can I reproduce this, is altiverb on the Master bus in multitrack?

[harisonzamperla]

It's altispace convolution reverb as master Fx send IAA. The send is on several different tracks and the buffer is set to It doesn't always happen but about 30% of the time there's crackles in the mixdown and then you finally hear the plug-in kick in and reverb/mixdown sound normal.

[harisonzamperla]

Also having issues with aufx: push and saffron saturator. Aufx push is amazing but sometimes it does a similar thing with rendering except it just adds a weird blip at the beginning as it kicks in. Saffron on the other hand never renders out the way it sounds. It also seems to double volume. Not sure why. Btw this isn't me complaining. I love multitrack and tell all my musician friends to buy a copy

[harisonzamperla]

This seems to happens semi-consistantly consistently with aufx: push or altispace in the FX master IAA Plugin slot. Not sure why. I did some testing. Doesnt actually seem related to the latency setting (like u explained) since it still happens on the highest setting and im on a iPhone 6plus. Sometimes there's a second of glitch bloop noise and then then the rest of the track is good. Other times there's about 3 seconds of silence and then the track continues normally. Im trying to find a pattern but it seems random so far. I also contacted aufx about it as well.

[pwnified]

I think I have a fix for this. It seems the problem is that client IAA units are not responding to the AudioUnitReset command. AudioUnitReset is specifically for clearing the plugin, ie. flushing out delay lines and memory buffers, so that you don't get a 'splash!' when the rendering starts. So, what multitrack is going to do instead, is to manually 'flush' the plugins by rendering silence for 20 seconds, before and after the render (mixdown, copy operation). This should be enough to flush out the longest reverb tails.

But there is another problem. Some plugins (Altispace, ahem) don't like having their time stamps reset either. It seems the plug takes it's sweet time to become acclimated to the new time stamps. The good news is that the manual flush above is working for this issue as well, as the worst case I was seeing was around 8 seconds and 20 is well more than that. BTW it doesn't take a full 20 seconds in realtime, rendering 20 seconds of audio only takes a second or so depending on the plugin.

So the only thing left right now is a SoundCloud issue, affecting all apps using the old api. Still no word from that company on how to fix it, so it's a major hurdle and I'm debating removing soundcloud support entirely.

[harisonzamperla]

Sounds great. I actually thought about doing this myself leaving silence at the beginning or tracks and then trimming them in audioshare. I didn't know there was a soundcloud issue. Thanks for the quick response.

[dcollins710]

Dropbox support would be awesome!

[dominicperry]

SoundCloud is pretty useless on iOS now anyway, since they made the app suitable only for listeners, not contributors. It's been handy to be able to upload from MT DAW in the past, but right now, unless you can control the parameters (like whether the clip is private) from the uploading application, you can't change anything in the SoundCloud app - you have to go to a browser to make the changes.

I think the SoundCloud devs lost their way, or the marketing department fired them all and replaced them with a spoon.

Dominic