AUGraph 正弦波损坏

Question

我有以下 AUGraph 代码，可将正弦波发生器连接到多通道混音器、输出设备，这没问题，但是，当您演奏时，生成的音调似乎已损坏...它几乎就在那里，但是出了点问题。

有什么想法吗？

import Cocoa
import CoreAudio
import AudioToolbox
import AudioUnit
import AVFoundation


let sampleRate:Float64 = 41000.0

class ViewController: NSViewController {


    var t = 0
    let callback2:AURenderCallback = {
        (inRefCon: UnsafeMutablePointer<Void>, ioActionFlags: UnsafeMutablePointer<AudioUnitRenderActionFlags>, inTimeStamp: UnsafePointer<AudioTimeStamp>, inBusNumber: UInt32, inNumberFrames: UInt32, ioData: UnsafeMutablePointer<AudioBufferList>)
        in

        let delta:Float = Float(880 * 2 * M_PI / sampleRate)
        let abl = UnsafeMutableAudioBufferListPointer(ioData)
        var x:Float = 0
        for buffer:AudioBuffer in abl {
            //x = self._x

            memset(buffer.mData, 0, Int(buffer.mDataByteSize))

            let s = sizeof(Float)
            let r = sizeof(Float32)
            let f = abl.count
            let buf:UnsafeMutablePointer<Float> = unsafeBitCast(buffer.mData, UnsafeMutablePointer<Float>.self)
            for var i:Int = 0; i < Int(inNumberFrames); i++
            {
                buf[i] = sin(x)
                x += delta
            }

            memcpy(buffer.mData, buf, Int(buffer.mDataByteSize));

            let x = 0
        }

        return noErr
    }


    struct MyAUGraphPlayer
    {
        var streamFormat:AudioStreamBasicDescription!

        var graph:AUGraph = AUGraph()

        var outputNode:AUNode!
        var mixerNode:AUNode!

        var outputUnit:AudioUnit!
        var mixerUnit:AudioUnit!

        var firstOutputSampleTime:Float64 = 0.0


        init()
        {

        }
    }

    func addAUNode(graph:AUGraph, inout desc:AudioComponentDescription) -> AUNode
    {
        var outputNode:AUNode = AUNode()
        let x = AUGraphAddNode(graph, &desc, &outputNode)
        print("x: \(x)")
        return outputNode
    }



    override func viewDidLoad() {
        super.viewDidLoad()

        doit()
    }



    func doit()
    {

        var desc:AudioStreamBasicDescription = AudioStreamBasicDescription()
        desc.mSampleRate       = sampleRate
        desc.mFormatID         = kAudioFormatLinearPCM
        desc.mFormatFlags      = kAudioFormatFlagsNativeFloatPacked
        desc.mFramesPerPacket  = 1
        desc.mChannelsPerFrame = 2
        desc.mBitsPerChannel   = UInt32(sizeof(Float32) * 8)
        desc.mBytesPerFrame    = desc.mChannelsPerFrame * (desc.mBitsPerChannel / 8)
        desc.mBytesPerPacket   = desc.mBytesPerFrame * desc.mFramesPerPacket



        var graph:AUGraph = AUGraph()
        var outputNode:AUNode = AUNode()
        var mixerNode:AUNode = AUNode()
        var outputUnit:AudioUnit = AudioUnit()
        var mixerUnit:AudioUnit = AudioUnit()

        let error = NewAUGraph(&graph)
        print("error: \(error)")

        // Output
        var outputDesc:AudioComponentDescription = AudioComponentDescription(componentType: OSType(kAudioUnitType_Output),
            componentSubType: OSType(kAudioUnitSubType_DefaultOutput),
            componentManufacturer: OSType(kAudioUnitManufacturer_Apple),
            componentFlags: 0,
            componentFlagsMask: 0)

        let a1 = AUGraphAddNode(graph, &outputDesc, &outputNode)
        print("a1: \(a1)")


        // Mixer
        var mixerDesc:AudioComponentDescription = AudioComponentDescription(componentType: OSType(kAudioUnitType_Mixer), componentSubType: OSType(kAudioUnitSubType_StereoMixer), componentManufacturer: OSType(kAudioUnitManufacturer_Apple), componentFlags: 0, componentFlagsMask: 0)

        let b1 = AUGraphAddNode(graph, &mixerDesc, &mixerNode)
        print("b1: \(b1)")


        // Connect nodes
        let y = AUGraphConnectNodeInput(graph,
            mixerNode,
            0,
            outputNode,
            0)
        print("y: \(y)")


        // open
        let open = AUGraphOpen(graph)
        print("graph should be open: \(open)")


        let ufa = AUGraphNodeInfo(graph, mixerNode, nil, &mixerUnit);
        print("ufa: \(ufa)")

        let uf = AUGraphNodeInfo(graph, outputNode, nil, &outputUnit);
        print("uf: \(uf)")



        // output
//        let w = AudioUnitSetProperty(outputUnit,
//            kAudioUnitProperty_StreamFormat,
//            kAudioUnitScope_Output,
//            0,
//            &desc,
//            UInt32(sizeof(AudioStreamBasicDescription) ))
//        print("w: \(w)")

//        let w2 = AudioUnitSetProperty(outputUnit,
//            kAudioUnitProperty_StreamFormat,
//            kAudioUnitScope_Input,
//            0,
//            &desc,
//            UInt32(sizeof(AudioStreamBasicDescription) ))
//        print("w2: \(w2)")
//

        var numbuses:UInt32 = 1


//        let gg = AudioUnitSetProperty(mixerUnit,
//            kAudioUnitProperty_ElementCount,
//            kAudioUnitScope_Input,
//            0,
//            &numbuses,
//            UInt32(sizeof(UInt32)))
//        print("gg: \(gg)")

//                let s = sizeof(UInt32)
//                numbuses = 1
//                let gg2 = AudioUnitSetProperty(mixerUnit,
//                    kAudioUnitProperty_ElementCount,
//                    kAudioUnitScope_Output,
//                    0,
//                    &numbuses,
//                    UInt32(sizeof(UInt32)))
//                print("gg2: \(gg2)")


//        let m1 = AudioUnitSetProperty(mixerUnit,
//            kAudioUnitProperty_StreamFormat,
//            kAudioUnitScope_Output,
//            0,
//            &desc,
//            UInt32(sizeof(AudioStreamBasicDescription) ))
//        print("m1: \(m1)")


        numbuses = 1
        for (var i:UInt32 = 0; i < numbuses; ++i)
        {
            //



            //
            let yy = AudioUnitSetParameter(mixerUnit, kMultiChannelMixerParam_Volume, kAudioUnitScope_Output, i, 1, 0);
            print("yy: \(yy)")

            let xx = AudioUnitSetParameter(mixerUnit, kMultiChannelMixerParam_Volume, kAudioUnitScope_Input, i, 1, 0);
            print("xx: \(xx)")

            let zz = AudioUnitSetParameter(mixerUnit, kMultiChannelMixerParam_Enable, kAudioUnitScope_Input, i, 1, 0);
            print("zz: \(zz)")

            let aa = AudioUnitSetParameter(mixerUnit, kMultiChannelMixerParam_Enable, kAudioUnitScope_Output, i, 1, 0);
            print("aa: \(aa)")

            var rcbs:AURenderCallbackStruct = AURenderCallbackStruct(inputProc: callback2, inputProcRefCon: &graph)

            let result1 = AUGraphSetNodeInputCallback(graph, mixerNode, i, &rcbs)
            print("result1: \(result1)")




//            let sf1 = AudioUnitSetProperty(mixerUnit,
//                kAudioUnitProperty_StreamFormat,
//                kAudioUnitScope_Input,
//                i,
//                &desc,
//                UInt32(sizeof(AudioStreamBasicDescription)))
//            print("sf1: \(sf1)")
//
//            let sf2 = AudioUnitSetProperty(mixerUnit,
//                kAudioUnitProperty_StreamFormat,
//                kAudioUnitScope_Output,
//                i,
//                &desc,
//                UInt32(sizeof(AudioStreamBasicDescription)))
//            print("sf2: \(sf2)")



        }


//        let sf2 = AudioUnitSetProperty(mixerUnit,
//            kAudioUnitProperty_StreamFormat,
//            kAudioUnitScope_Output,
//            0,
//            &desc,
//            UInt32(sizeof(AudioStreamBasicDescription)))
//        print("sf2: \(sf2)")
//        
//        
//        let o1 = AudioUnitSetProperty(outputUnit,
//            kAudioUnitProperty_StreamFormat,
//            kAudioUnitScope_Output,
//            1,
//            &desc,
//            UInt32(sizeof(AudioStreamBasicDescription)))
//        print("o1: \(o1)")
//        



        let yu = AUGraphInitialize(graph)
        print("yu: \(yu)")


        let ee = AUGraphStart(graph)
        print("ee: \(ee)")




        CAShow(UnsafeMutablePointer(graph))
    }


}

Answer 1

您要求每帧 2 个通道，但每个数据包的字节数只够 1 个通道。检查音频属性设置器上的错误 return 值。

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