Is it possible to schedule a volume change on kAudioUnitSubType_MatrixMixer or kAudioUnitSubType_MultiChannelMixer that happens instantly?
I am attempting to change the volume of a mixer at a specific sample time in a kAudioUnitRenderAction_PreRender callback. I have tried AudioUnitSetParameter with an offset as well as AudioUnitScheduleParameters with an immediate offset. In both cases, the volume change is not instant. It begins at the exact sample that I schedule the change to happen, but takes some time to complete. The mixer is applying some smoothing to the volume change. Measurements indicate that the kAudioUnitSubType_MatrixMixer takes 2235 samples to complete its volume change and kAudioUnitSubType_MultiChannelMixer takes 1102 samples to complete its volume change. These measurements were taken with the entire graph running at 44.1kHz. While applying some smoothing makes sense when the user makes changes via UI, it doesn’t make any sense when I am programmatically changing the volume, especially when using AudioUnitScheduleParameters with an immediate offset. It is possible to force the mixer to immediately change its volume by calling AudioUnitReset after setting the volume in the kAudioUnitRenderAction_PreRender callback, but this defeats the scheduled change. Is it possible to schedule a volume change on kAudioUnitSubType_MatrixMixer or kAudioUnitSubType_MultiChannelMixer that happens instantly? — Dominic Feira _______________________________________________ Do not post admin requests to the list. They will be ignored. Coreaudio-api mailing list ([email protected]) Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/coreaudio-api/archive%40mail-archive.com This email sent to [email protected]
