将KAudioUnitSubType_Reverb2添加到AUGraph时，AUGraphInitialize错误代码-10868

我正在尝试将类型为kAudioUnitSubType_Reverb2的AUGraph添加到AUGraph并在-10868 (kAudioUnitErr_FormatNotSupported)获得-10868 (kAudioUnitErr_FormatNotSupported)支持的错误。 我的出发点是Apple的iPhoneMixerEQGraphTest示例应用程序，我基本上只为混响添加了一个新的AudioUnit，但无法让它工作。

这是代码 –

 - (void)initializeAUGraph { printf("initializeAUGraph\n"); AUNode outputNode; AUNode eqNode; AUNode mixerNode; AUNode reverbNode; printf("create client ASBD\n"); // client format audio goes into the mixer mClientFormat.SetCanonical(2, true); mClientFormat.mSampleRate = kGraphSampleRate; mClientFormat.Print(); printf("create output ASBD\n"); // output format mOutputFormat.SetAUCanonical(2, false); mOutputFormat.mSampleRate = kGraphSampleRate; mOutputFormat.Print(); OSStatus result = noErr; // load up the audio data [self performSelectorInBackground:@selector(loadFiles) withObject:nil]; printf("new AUGraph\n"); // create a new AUGraph result = NewAUGraph(&mGraph); if (result) { printf("NewAUGraph result %ld %08X %4.4s\n", result, (unsigned int)result, (char*)&result); return; } // create three CAComponentDescription for the AUs we want in the graph // output unit CAComponentDescription output_desc(kAudioUnitType_Output, kAudioUnitSubType_RemoteIO, kAudioUnitManufacturer_Apple); // iPodEQ unit CAComponentDescription eq_desc(kAudioUnitType_Effect, kAudioUnitSubType_AUiPodEQ, kAudioUnitManufacturer_Apple); // multichannel mixer unit CAComponentDescription mixer_desc(kAudioUnitType_Mixer, kAudioUnitSubType_MultiChannelMixer, kAudioUnitManufacturer_Apple); // reverb unit CAComponentDescription reverb_desc(kAudioUnitType_Effect, kAudioUnitSubType_Reverb2, kAudioUnitManufacturer_Apple); printf("add nodes\n"); // create a node in the graph that is an AudioUnit, using the supplied AudioComponentDescription to find and open that unit result = AUGraphAddNode(mGraph, &output_desc, &outputNode); if (result) { printf("AUGraphNewNode 1 result %lu %4.4s\n", result, (char*)&result); return; } result = AUGraphAddNode(mGraph, &eq_desc, &eqNode); if (result) { printf("AUGraphNewNode 2 result %lu %4.4s\n", result, (char*)&result); return; } result = AUGraphAddNode(mGraph, &mixer_desc, &mixerNode); if (result) { printf("AUGraphNewNode 3 result %lu %4.4s\n", result, (char*)&result); return; } result = AUGraphAddNode(mGraph, &reverb_desc, &reverbNode); if (result) { printf("AUGraphNewNode 4 result %lu %4.4s\n", result, (char*)&result); return; } // connect a node's output to a node's input // mixer -> eq -> output result = AUGraphConnectNodeInput(mGraph, mixerNode, 0, eqNode, 0); if (result) { printf("AUGraphConnectNodeInput result %lu %4.4s\n", result, (char*)&result); return; } result = AUGraphConnectNodeInput(mGraph, eqNode, 0, reverbNode, 0); if (result) { printf("AUGraphConnectNodeInput result %lu %4.4s\n", result, (char*)&result); return; } result = AUGraphConnectNodeInput(mGraph, reverbNode, 0, outputNode, 0); if (result) { printf("AUGraphConnectNodeInput reverb result %lu %4.4s\n", result, (char*)&result); return; } // open the graph AudioUnits are open but not initialized (no resource allocation occurs here) result = AUGraphOpen(mGraph); if (result) { printf("AUGraphOpen result %ld %08X %4.4s\n", result, (unsigned int)result, (char*)&result); return; } // grab the audio unit instances from the nodes result = AUGraphNodeInfo(mGraph, mixerNode, NULL, &mMixer); if (result) { printf("AUGraphNodeInfo result %ld %08X %4.4s\n", result, (unsigned int)result, (char*)&result); return; } result = AUGraphNodeInfo(mGraph, eqNode, NULL, &mEQ); if (result) { printf("AUGraphNodeInfo result %ld %08X %4.4s\n", result, (unsigned int)result, (char*)&result); return; } result = AUGraphNodeInfo(mGraph, reverbNode, NULL, &mReverb); if (result) { printf("AUGraphNodeInfo reverb result %ld %08X %4.4s\n", result, (unsigned int)result, (char*)&result); return; } // set bus count UInt32 numbuses = 2; printf("set input bus count %lu\n", numbuses); result = AudioUnitSetProperty(mMixer, kAudioUnitProperty_ElementCount, kAudioUnitScope_Input, 0, &numbuses, sizeof(numbuses)); if (result) { printf("AudioUnitSetProperty result %ld %08X %4.4s\n", result, (unsigned int)result, (char*)&result); return; } for (int i = 0; i < numbuses; ++i) { // setup render callback struct AURenderCallbackStruct rcbs; rcbs.inputProc = &renderInput; rcbs.inputProcRefCon = &mUserData; printf("set AUGraphSetNodeInputCallback\n"); // set a callback for the specified node's specified input result = AUGraphSetNodeInputCallback(mGraph, mixerNode, i, &rcbs); if (result) { printf("AUGraphSetNodeInputCallback result %ld %08X %4.4s\n", result, (unsigned int)result, (char*)&result); return; } printf("set input bus %d, client kAudioUnitProperty_StreamFormat\n", i); // set the input stream format, this is the format of the audio for mixer input result = AudioUnitSetProperty(mMixer, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input, i, &mClientFormat, sizeof(mClientFormat)); if (result) { printf("AudioUnitSetProperty result %ld %08X %4.4s\n", result, (unsigned int)result, (char*)&result); return; } } printf("get EQ kAudioUnitProperty_FactoryPresets\n"); // get the eq's factory preset list -- this is a read-only CFArray array of AUPreset structures // host owns the retuned array and should release it when no longer needed UInt32 size = sizeof(mEQPresetsArray); result = AudioUnitGetProperty(mEQ, kAudioUnitProperty_FactoryPresets, kAudioUnitScope_Global, 0, &mEQPresetsArray, &size); if (result) { printf("AudioUnitGetProperty result %ld %08X %4.4s\n", result, (unsigned int)result, (char*)&result); return; } /* this code can be used if you're interested in dumping out the preset list printf("iPodEQ Factory Preset List:\n"); UInt8 count = CFArrayGetCount(mEQPresetsArray); for (int i = 0; i presetName); }*/ printf("set output kAudioUnitProperty_StreamFormat\n"); // set the output stream format of the mixer result = AudioUnitSetProperty(mMixer, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output, 0, &mOutputFormat, sizeof(mOutputFormat)); if (result) { printf("AudioUnitSetProperty result %ld %08X %4.4s\n", result, (unsigned int)result, (char*)&result); return; } printf("set render notification\n"); // add a render notification, this is a callback that the graph will call every time the graph renders // the callback will be called once before the graph's render operation, and once after the render operation is complete result = AUGraphAddRenderNotify(mGraph, renderNotification, &mUserData); if (result) { printf("AUGraphAddRenderNotify result %ld %08X %4.4s\n", result, (unsigned int)result, (char*)&result); return; } printf("AUGraphInitialize\n"); // now that we've set everything up we can initialize the graph, this will also validate the connections result = AUGraphInitialize(mGraph); if (result) { printf("AUGraphInitialize result %ld %08X %4.4s\n", result, (unsigned int)result, (char*)&result); return; } // ---- result here is error code 10868 CAShow(mGraph); } 

Answer 1

出于某种原因，一些AU节点默认采用float格式的流格式，而其他节点则采用整数forms。 如果流格式不匹配，则会出现此错误。 因此，您需要在均衡器节点和混响节点之间添加格式转换器：

  AudioComponentDescription convertUnitDescription; convertUnitDescription.componentManufacturer = kAudioUnitManufacturer_Apple; convertUnitDescription.componentType = kAudioUnitType_FormatConverter; convertUnitDescription.componentSubType = kAudioUnitSubType_AUConverter; convertUnitDescription.componentFlags = 0; convertUnitDescription.componentFlagsMask = 0; result = AUGraphAddNode (graph, &convertUnitDescription, &convertNode); NSCAssert (result == noErr, @"Unable to add the converted unit to the audio processing graph. Error code: %d '%.4s'", (int) result, (const char *)&result); 

确保将转换器节点输入的流格式设置为均衡器节点输出的格式：

  AudioStreamBasicDescription eqStreamFormat; UInt32 streamFormatSize = sizeof(eqStreamFormat); result = AudioUnitGetProperty(eqUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Output, 0, &eqStreamFormat, &streamFormatSize); NSAssert (result == noErr, @"Unable to get eq output format. Error code: %d '%.4s'", (int) result, (const char *)&result); result = AudioUnitSetProperty(convertUnit, kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input, 0, &eqStreamFormat, streamFormatSize); NSAssert (result == noErr, @"Unable to set converter input format. Error code: %d '%.4s'", (int) result, (const char *)&result); 

并对转换器的输出执行相同操作，并使用混响的输入格式进行设置。 这应该使您的图形初始化并运行，但是如果您设法使混响节点实际上做某事，请告诉我，因为它对我不起作用。