Ios 停止AudioUnit录制后出错
我正在尝试使用以下代码从iPhone的麦克风获取音频输入:Ios 停止AudioUnit录制后出错,ios,objective-c,iphone,core-audio,audiounit,Ios,Objective C,Iphone,Core Audio,Audiounit,我正在尝试使用以下代码从iPhone的麦克风获取音频输入: @property (nonatomic) AudioUnit rioUnit; @property (nonatomic) CAStreamBasicDescription outputCASBD; (...) // set our required format - LPCM non-interleaved 32 bit floating point CAStreamBasicDescription outFormat = CA
@property (nonatomic) AudioUnit rioUnit;
@property (nonatomic) CAStreamBasicDescription outputCASBD;
(...)
// set our required format - LPCM non-interleaved 32 bit floating point
CAStreamBasicDescription outFormat = CAStreamBasicDescription(44100, // sample rate
kAudioFormatLinearPCM, // format id
4, // bytes per packet
1, // frames per packet
4, // bytes per frame
1, // channels per frame
32, // bits per channel
kAudioFormatFlagIsFloat | kAudioFormatFlagIsNonInterleaved);
try {
// Open the output unit
AudioComponentDescription desc;
desc.componentType = kAudioUnitType_Output;
desc.componentSubType = kAudioUnitSubType_RemoteIO;
desc.componentManufacturer = kAudioUnitManufacturer_Apple;
desc.componentFlags = 0;
desc.componentFlagsMask = 0;
AudioComponent comp = AudioComponentFindNext(NULL, &desc);
AudioComponentInstanceNew(comp, &_rioUnit);
UInt32 one = 1;
XThrowIfError(AudioUnitSetProperty(_rioUnit, kAudioOutputUnitProperty_EnableIO, kAudioUnitScope_Input, 1, &one, sizeof(one)), "couldn't enable input on the remote I/O unit");
AURenderCallbackStruct callbackStruct;
callbackStruct.inputProc = renderInput;
callbackStruct.inputProcRefCon = (__bridge void*)self;
XThrowIfError(AudioUnitSetProperty(_rioUnit, kAudioOutputUnitProperty_SetInputCallback, kAudioUnitScope_Global, 0, &callbackStruct, sizeof(callbackStruct)), "couldn't set remote i/o render callback");
XThrowIfError(AudioUnitSetProperty(_rioUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input, 0, &outFormat, sizeof(outFormat)), "couldn't set the remote I/O unit's output client format");
XThrowIfError(AudioUnitSetProperty(_rioUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output, 1, &outFormat, sizeof(outFormat)), "couldn't set the remote I/O unit's input client format");
XThrowIfError(AudioUnitInitialize(_rioUnit), "couldn't initialize the remote I/O unit");
XThrowIfError(AudioOutputUnitStart(_rioUnit), "couldn't start the remote I/O unit");
}
catch (CAXException &e) {
char buf[256];
fprintf(stderr, "Error: %s (%s)\n", e.mOperation, e.FormatError(buf));
}
catch (...) {
fprintf(stderr, "An unknown error occurred\n");
}
// Allocate our own buffers (1 channel, 16 bits per sample, thus 16 bits per frame, thus 2 bytes per frame).
// Practice learns the buffers used contain 512 frames, if this changes it will be fixed in processAudio.
// will need float for accellerate fft (input is 16 bit signed integer) so make space...
_tempBuffer.mNumberChannels = outFormat.mChannelsPerFrame;
_tempBuffer.mDataByteSize = 512 * outFormat.mBytesPerFrame * 2;
_tempBuffer.mData = malloc( self.tempBuffer.mDataByteSize );
一切都很好,直到我想停止听麦克风输入
我正在这样做:
AudioOutputUnitStop(_rioUnit);
AudioUnitUninitialize(_rioUnit);
AudioComponentInstanceDispose(_rioUnit);
_rioUnit = nil;
但是我从为kAudioOutputUnitProperty\u SetInputCallback
定义的回调函数中得到一个错误
错误是:AURemoteIO::IOThread(14):EXC\u BAD\u访问(code=1,地址=0x800000c)
在我看来,AudioUnit的InputCallback仍然在被调用,即使我正在停止它,对其实例进行单元化和处理
为什么会发生这种情况,以及如何防止在停止、统一化和处置其实例后调用InputCallback?首先,确保“rioUnit”在停止时的值与在开始时的值相同
正在另一个异步线程中调用音频输入回调。因此,在取消初始化或处理音频单元或任何其他所需的数据结构之前,您可能需要等待线程也停止(这通常发生在不到2个音频缓冲区持续时间内,因此等待的时间可能是合理的)
\u rioUnit=nil;//导致EXC\u坏访问错误
将nil
更改为NULL
解决了问题:
\u rioUnit=NULL;//工作平稳
我从这篇文章中得到了这个想法:
此外,还概述了
Objective-C
中nil
和NULL
之间的区别。您使用的是曲线图吗?如果是,您是否正在调用AUGraphStop()?我不是。结果是\u rioUnit=nil代码>是导致问题的原因。将其更改为\u rioUnit=NULL代码>解决了它。谢谢你的想法,我还认为它没有初始化错误的\u rioUnit
。然而,事实证明,它实际上并没有正确地对其进行初始化。必须将其设置为NULL
,而不是nil
。请参阅我的答案以了解更多详细信息。