ios - Swift 中的 AudioBufferList

Question

我正在尝试将以下代码转换为 Swift:

CMSampleBufferRef sampleBuffer = [assetOutput copyNextSampleBuffer];

CMBlockBufferRef blockBuffer;

AudioBufferList audioBufferList;

CMSampleBufferGetAudioBufferListWithRetainedBlockBuffer(sampleBuffer, NULL, &audioBufferList, sizeof(AudioBufferList), NULL, NULL, kCMSampleBufferFlag_AudioBufferList_Assure16ByteAlignment, &blockBuffer);

for (NSUInteger i = 0; i < audioBufferList.mNumberBuffers; i++) {
  AudioBuffer audioBuffer = audioBufferList.mBuffers[i];
  [audioStream writeData:audioBuffer.mData maxLength:audioBuffer.mDataByteSize];
}

CFRelease(blockBuffer);
CFRelease(sampleBuffer);

无论我尝试什么，我似乎都无法遍历 audioBuffer 列表。有人有答案吗？

Answer 1

Swift-3 中的代码转换

var sampleBuffer: CMSampleBuffer? = assetOutput.copyNextSampleBuffer()
let audioStream = OutputStream()
var blockBuffer: CMBlockBuffer?
var audioBufferList = AudioBufferList()

CMSampleBufferGetAudioBufferListWithRetainedBlockBuffer(sampleBuffer, nil, &audioBufferList, MemoryLayout<AudioBufferList>.size, nil, nil, kCMSampleBufferFlag_AudioBufferList_Assure16ByteAlignment, &blockBuffer)

let buffers = UnsafeBufferPointer<AudioBuffer>(start: &audioBufferList.mBuffers, count: Int(audioBufferList.mNumberBuffers))

for audioBuffer in buffers {
    let frame = audioBuffer.mData?.assumingMemoryBound(to: UInt8.self)
    audioStream.write(frame!, maxLength: Int(audioBuffer.mDataByteSize))
}