AVAudioConverter seems broken in iOS 10. The code was working in iOS 9 and now
Error Domain=NSOSStatusErrorDomain Code=-50 "(null)"
is returned no matter what audio format is used. It suprises me every year, that basic library functionality stops working.
func audioConverterFailureIOS10() {
// Describe the audio format
let inFormat = AVAudioFormat(standardFormatWithSampleRate: 44100, channels: 2)
let outFormat = AVAudioFormat(standardFormatWithSampleRate: 22050, channels: 2)
// Allocate buffers
let outBuffer = AVAudioPCMBuffer(pcmFormat: outFormat, frameCapacity: 1024)
// Create an input block that is called when the converter needs input
let inputBlock : AVAudioConverterInputBlock = { (inNumPackets, outStatus) -> AVAudioBuffer? in
// Fails before entering here
return nil
}
// Create the audio converter
let converter = AVAudioConverter(from: inFormat, to: outFormat)
var error : NSError?
_ = converter.convert(to: outBuffer, error: &error, withInputFrom: inputBlock)
// Error Domain=NSOSStatusErrorDomain Code=-50 "(null)"
print(error)
}
So, it turned out that the outBuffer frameLength has to be set to the frameCapacity. As default the length is 0 and is apparently treated differently on iOS 10
来源:https://stackoverflow.com/questions/39714244/avaudioconverter-is-broken-in-ios-10