Question

我正在尝试在GLES应用程序（Unity3d）中编写麦克风功率计模块。它在UIKit应用程序中工作正常。但是当我集成到我的unity3d项目中时，AudioQueue无法启动属性。调用AudioQueueStart的结果代码总是-50，但-50是什么意思？我在iOS Developer Library中找不到引用。

我已经搜索过这个问题并且知道有人在cocos2d应用程序中遇到了同样的问题。也许这有一定的相关性。

以下是我的启动音频队列代码：

UInt32 ioDataSize = sizeof(sampleRate);
AudioSessionGetProperty(kAudioSessionProperty_CurrentHardwareSampleRate, &ioDataSize, &sampleRate); //returns noErr
format.mSampleRate = sampleRate;
format.mFormatID = kAudioFormatLinearPCM;
format.mFormatFlags = kAudioFormatFlagIsSignedInteger | kAudioFormatFlagIsPacked;
format.mFramesPerPacket = format.mChannelsPerFrame = 1;
format.mBitsPerChannel = 16;
format.mBytesPerPacket = format.mBytesPerFrame = 2;

AudioQueueNewInput(&format, listeningCallback, self, NULL, NULL, 0, &queue); //returns noErr

AudioQueueBufferRef buffers[3];
for (NSInteger i = 0; i < 3; ++i) { 
    AudioQueueAllocateBuffer(queue, 735, &buffers[i]); //returns noErr
    AudioQueueEnqueueBuffer(queue, buffers[i], 0, NULL); //returns noErr
}

levels = (AudioQueueLevelMeterState *)calloc(sizeof(AudioQueueLevelMeterState), format.mChannelsPerFrame);
UInt32 trueValue = true;
AudioQueueSetProperty(queue, kAudioQueueProperty_EnableLevelMetering, &trueValue, sizeof(UInt32)); //returns noErr

AudioQueueStart(queue, NULL); //returns -50

Answer 1

下面适用于我：

添加：

createdon=DESC

之前AVAudioSession * session = [AVAudioSession sharedInstance]; if (!session) printf("ERROR INITIALIZING AUDIO SESSION! \n"); else{ [session setCategory:AVAudioSessionCategoryPlayAndRecord error:&nsError]; if (nsError) printf("couldn't set audio category!"); [session setActive:YES error:&nsError]; if (nsError) printf("AudioSession setActive = YES failed"); }

Answer 2

您是否检查过AudioSession处于AVAudioSessionCategoryRecord或AVAudioSessionCategoryPlayAndRecord模式？

http://developer.apple.com/library/ios/#documentation/Audio/Conceptual/AudioSessionProgrammingGuide/AudioSessionCategories/AudioSessionCategories.html#//apple_ref/doc/uid/TP40007875-CH4-SW1

音频队列：AudioQueueStart返回-50

2 个答案: