No sound from some AU´s

For instance AudioEase Deep Phase Nine from the Nautilus bundle returns err=-50 after AudioUnitRender() is called.
Voxengo GEQ is another candidate that doesn´t work.

This is in 1.46, but the AU hosting code did not change that much (from a rendering point of view).

Could you please try if this is still the case and maybe tell me what´s the problem there?

Sorry, up to my neck in other stuff this week and no time to try out plugins. But you’re right, the audio pipeline stayed pretty much the same.

Seems like when I’m forcing getNumChannels() to return 2 ins and 2 outs, then it works! Maybe these plugins are just buggy and report a higher number of channels than they can actually handle?

Could be…

As an improvement for future versions of JUCE, may I suggest some functions that allow asking the plugin its acceptable I/O channel configurations, such as 1/2, 2/2, 2/5, so the user can decide how many I/O’s he wants. So he asks the plugin “What can you do?”, the plugin replies “1/2, 2/2, 2/5, …” and then the user chooses a config of the available configs via some other function. If the plugin doesn’t support that, it just returns one single IO config and that’s it.
In the 1.46 wrapper the highest number of channels is always selected, which can ofcourse lead to wasting CPU if not such a high number of channels is needed (in 98% of the time 2/2 will do anyway) - plus some plugins really seem not to like it, although they report they support it.