How do I call CMSampleBufferGetAudioBufferListWithRetainedBlockBuffer?

Question

I\'m trying to figure out how to call this AVFoundation function in Swift. I\'ve spent a ton of time fiddling with declarations and syntax, and got this far.

Answer 1

it works for me. try it:

let musicUrl: NSURL = mediaItemCollection.items[0].valueForProperty(MPMediaItemPropertyAssetURL) as! NSURL
let asset: AVURLAsset = AVURLAsset(URL: musicUrl, options: nil)
let assetOutput = AVAssetReaderTrackOutput(track: asset.tracks[0] as! AVAssetTrack, outputSettings: nil)

var error : NSError?

let assetReader: AVAssetReader = AVAssetReader(asset: asset, error: &error)

if error != nil {
    print("Error asset Reader: \(error?.localizedDescription)")
}

assetReader.addOutput(assetOutput)
assetReader.startReading()

let sampleBuffer: CMSampleBufferRef = assetOutput.copyNextSampleBuffer()

var audioBufferList = AudioBufferList(mNumberBuffers: 1, mBuffers: AudioBuffer(mNumberChannels: 0, mDataByteSize: 0, mData: nil))
var blockBuffer: Unmanaged? = nil


CMSampleBufferGetAudioBufferListWithRetainedBlockBuffer(
    sampleBuffer,
    nil,
    &audioBufferList,
    sizeof(audioBufferList.dynamicType), // instead of UInt(sizeof(audioBufferList.dynamicType))
    nil,
    nil,
    UInt32(kCMSampleBufferFlag_AudioBufferList_Assure16ByteAlignment),
    &blockBuffer
)