my record work normally, but the problem is after WebRTC call, i got crash
required condition is false: format.sampleRate == hwFormat.sampleRate
here is how i start crash and installTap:
func startRecord() {
self.filePath = nil
print("last format: \(audioEngine.inputNode.inputFormat(forBus: 0).sampleRate)")
let session = AVAudioSession.sharedInstance()
do {
try session.setCategory(.playAndRecord, options: .mixWithOthers)
} catch {
print("======== Error setting setCategory \(error.localizedDescription)")
}
do {
try session.setPreferredSampleRate(44100.0)
} catch {
print("======== Error setting rate \(error.localizedDescription)")
}
do {
try session.setPreferredIOBufferDuration(0.005)
} catch {
print("======== Error IOBufferDuration \(error.localizedDescription)")
}
do {
try session.setActive(true, options: .notifyOthersOnDeactivation)
} catch {
print("========== Error starting session \(error.localizedDescription)")
}
let format = AVAudioFormat(commonFormat: AVAudioCommonFormat.pcmFormatInt16,
sampleRate: 44100.0,
// sampleRate: audioEngine.inputNode.inputFormat(forBus: 0).sampleRate,
channels: 1,
interleaved: true)
audioEngine.connect(audioEngine.inputNode, to: mixer, format: format)
audioEngine.connect(mixer, to: audioEngine.mainMixerNode, format: format)
let dir = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first! as String
filePath = dir.appending("/\(UUID.init().uuidString).wav")
_ = ExtAudioFileCreateWithURL(URL(fileURLWithPath: filePath!) as CFURL,
kAudioFileWAVEType,(format?.streamDescription)!,nil,AudioFileFlags.eraseFile.rawValue,&outref)
mixer.installTap(onBus: 0, bufferSize: AVAudioFrameCount((format?.sampleRate)!), format: format, block: { (buffer: AVAudioPCMBuffer!, time: AVAudioTime!) -> Void in
let audioBuffer : AVAudioBuffer = buffer
_ = ExtAudioFileWrite(self.outref!, buffer.frameLength, audioBuffer.audioBufferList)
})
try! audioEngine.start()
startMP3Rec(path: filePath!, rate: 128)
}
func stopRecord() {
self.audioFilePlayer.stop()
self.audioEngine.stop()
self.mixer.removeTap(onBus: 0)
self.stopMP3Rec()
ExtAudioFileDispose(self.outref!)
try? AVAudioSession.sharedInstance().setActive(false)
}
func startMP3Rec(path: String, rate: Int32) {
self.isMP3Active = true
var total = 0
var read = 0
var write: Int32 = 0
let mp3path = path.replacingOccurrences(of: "wav", with: "mp3")
var pcm: UnsafeMutablePointer<FILE> = fopen(path, "rb")
fseek(pcm, 4*1024, SEEK_CUR)
let mp3: UnsafeMutablePointer<FILE> = fopen(mp3path, "wb")
let PCM_SIZE: Int = 8192
let MP3_SIZE: Int32 = 8192
let pcmbuffer = UnsafeMutablePointer<Int16>.allocate(capacity: Int(PCM_SIZE*2))
let mp3buffer = UnsafeMutablePointer<UInt8>.allocate(capacity: Int(MP3_SIZE))
let lame = lame_init()
lame_set_num_channels(lame, 1)
lame_set_mode(lame, MONO)
lame_set_in_samplerate(lame, 44100)
lame_set_brate(lame, rate)
lame_set_VBR(lame, vbr_off)
lame_init_params(lame)
DispatchQueue.global(qos: .default).async {
while true {
pcm = fopen(path, "rb")
fseek(pcm, 4*1024 + total, SEEK_CUR)
read = fread(pcmbuffer, MemoryLayout<Int16>.size, PCM_SIZE, pcm)
if read != 0 {
write = lame_encode_buffer(lame, pcmbuffer, nil, Int32(read), mp3buffer, MP3_SIZE)
fwrite(mp3buffer, Int(write), 1, mp3)
total += read * MemoryLayout<Int16>.size
fclose(pcm)
} else if !self.isMP3Active {
_ = lame_encode_flush(lame, mp3buffer, MP3_SIZE)
_ = fwrite(mp3buffer, Int(write), 1, mp3)
break
} else {
fclose(pcm)
usleep(50)
}
}
lame_close(lame)
fclose(mp3)
fclose(pcm)
self.filePathMP3 = mp3path
}
}
func stopMP3Rec() {
self.isMP3Active = false
}
as first time run app, i log the last format using
print("last format: \(audioEngine.inputNode.inputFormat(forBus: 0).sampleRate)")
--> return 0 -> record normally next time return 44100 -> record normally
but after webrtc call, i got 48000, then it make crash in this line
self.audioEngine.connect(self.audioEngine.inputNode, to: self.mixer, format: format)
i spend 4 hour in stackoverflow but no solution work for me.
i dont want 48000 format, because i have set the sample to
sampleRate: audioEngine.inputNode.inputFormat(forBus: 0).sampleRate,
-> my output is hard to hear, i can recognize my voice :(
So i think 44100 is the best
can someone give me some advices? Thanks
This line bugs.
let format = AVAudioFormat(commonFormat: AVAudioCommonFormat.pcmFormatInt16, ...
AVAudioCommonFormat.pcmFormatInt16 not works by default.
You should use .pcmFormatFloat32
And the xcode tip is obvious,
the crash line
self.audioEngine.connect(self.audioEngine.inputNode, to: self.mixer, format: format)
You know it by print mixer.inputFormat(forBus: 0 )
then you got sample rate 48000 by the actual device. you can get 44100 by converting
just use AVAudioConverter to do down sample audio buffer.
let input = engine.inputNode
let bus = 0
let inputFormat = input.outputFormat(forBus: bus )
guard let outputFormat = AVAudioFormat(commonFormat: .pcmFormatFloat32, sampleRate: 44100, channels: 1, interleaved: true), let converter = AVAudioConverter(from: inputFormat, to: outputFormat) else{
return
}
if let convertedBuffer = AVAudioPCMBuffer(pcmFormat: outputFormat, frameCapacity: AVAudioFrameCount(outputFormat.sampleRate) * buffer.frameLength / AVAudioFrameCount(buffer.format.sampleRate)){
var error: NSError?
let status = converter.convert(to: convertedBuffer, error: &error, withInputFrom: inputCallback)
assert(status != .error)
print(convertedBuffer.format)
}