Time stamps and Audiobus
My app plays audio while recording from the hardware input. To synchronise the recorded audio with playback I calculate the difference between the audio callback and render callback timestamps. This works perfectly until I load my app into an input slot in Audiobus then the resulting audio is out of sync. When using my app stand alone I get roughly 2290 frames difference between callbacks which is accurate enough to put my audio in perfect sync however If it's loaded into Audiobus as an input I get only a 79 frame difference and my audio is out of sync.
Are the time stamps altered by Audiobus or TAAE somewhere?
Does anyone know of a way to calculate the true timestamp difference when in Audiobus as an input?
Interestingly LoopyHD behaves the same way. If you add it as an input slot in Audiobus and try to record it's own metronome back into the iPad mic then the result is out of sync.
Any help appreciated!