Reputation: 303
I would like to know if it's possible to resample an already written AVAudioFile
.
All the references that I found don't work on this particular problem, since:
AVAudioFile
, while installTap
is running. In this approach, the AVAudioConverter
works in each buffer chunk given by the inputNode
and appends it in the AVAudioFile
. [1] [2]The point is that I would like to resample my audio file regardless of the recording process.
The harder approach would be to upsample the signal by a L factor and applying decimation by a factor of M, using vDSP:
Audio on Compact Disc has a sampling rate of 44.1 kHz; to transfer it to a digital medium that uses 48 kHz, method 1 above can be used with L = 160, M = 147 (since 48000/44100 = 160/147). For the reverse conversion, the values of L and M are swapped. Per above, in both cases, the low-pass filter should be set to 22.05 kHz. [3]
The last one obviously seems like a too hard coded way to solve it. I hope there's a way to resample it with AVAudioConverter, but it lacks documentation :(
Upvotes: 3
Views: 735