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Added basic output device channel mapping support

CQTexperiment
Chris Moeller 2013-10-07 00:24:00 -07:00
parent 7a4e297828
commit 167524b6f2
2 changed files with 85 additions and 2 deletions
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1
Audio/Output/OutputCoreAudio.h
View File

@ -17,6 +17,7 @@
@interface OutputCoreAudio : NSObject {
OutputNode * outputController;
AudioDeviceID outputDeviceID;
AudioUnit outputUnit;
AURenderCallbackStruct renderCallback;
AudioStreamBasicDescription deviceFormat; // info about the default device

86
Audio/Output/OutputCoreAudio.m
View File

@ -96,6 +96,7 @@ static OSStatus Sound_Renderer(void *inRefCon, AudioUnitRenderActionFlags *ioAc
}
printf("DEVICE: %i\n", deviceID);
outputDeviceID = deviceID;
err = AudioUnitSetProperty(outputUnit,
kAudioOutputUnitProperty_CurrentDevice,
@ -118,7 +119,12 @@ static OSStatus Sound_Renderer(void *inRefCon, AudioUnitRenderActionFlags *ioAc
if (outputUnit)
[self stop];
ComponentDescription desc;
AudioObjectPropertyAddress propertyAddress = {
.mElement = kAudioObjectPropertyElementMaster
};
UInt32 dataSize;
ComponentDescription desc;
OSStatus err;
desc.componentType = kAudioUnitType_Output;
@ -177,7 +183,75 @@ static OSStatus Sound_Renderer(void *inRefCon, AudioUnitRenderActionFlags *ioAc
// change output format...
deviceFormat.mChannelsPerFrame = 2; // HACK: Force stereo. This breaks surround, but surround is likely busted anyways because there isn't a correct channel mapping.
// The default channel map is silence
SInt32 deviceChannelMap [deviceFormat.mChannelsPerFrame];
for(UInt32 i = 0; i < deviceFormat.mChannelsPerFrame; ++i)
deviceChannelMap[i] = -1;
// Determine the device's preferred stereo channels for output mapping
if(1 == deviceFormat.mChannelsPerFrame || 2 == deviceFormat.mChannelsPerFrame) {
propertyAddress.mSelector = kAudioDevicePropertyPreferredChannelsForStereo;
propertyAddress.mScope = kAudioDevicePropertyScopeOutput;
UInt32 preferredStereoChannels [2] = { 1, 2 };
if(AudioObjectHasProperty(outputDeviceID, &propertyAddress)) {
dataSize = sizeof(preferredStereoChannels);
err = AudioObjectGetPropertyData(outputDeviceID, &propertyAddress, 0, nil, &dataSize, &preferredStereoChannels);
}
AudioChannelLayout stereoLayout;
stereoLayout.mChannelLayoutTag = kAudioChannelLayoutTag_Stereo;
const AudioChannelLayout *specifier [1] = { &stereoLayout };
SInt32 stereoChannelMap [2] = { 1, 2 };
dataSize = sizeof(stereoChannelMap);
err = AudioFormatGetProperty(kAudioFormatProperty_ChannelMap, sizeof(specifier), specifier, &dataSize, stereoChannelMap);
if(noErr == err) {
deviceChannelMap[preferredStereoChannels[0] - 1] = stereoChannelMap[0];
deviceChannelMap[preferredStereoChannels[1] - 1] = stereoChannelMap[1];
}
else {
// Just use a channel map that makes sense
deviceChannelMap[preferredStereoChannels[0] - 1] = 0;
deviceChannelMap[preferredStereoChannels[1] - 1] = 1;
}
}
// Determine the device's preferred multichannel layout
else {
propertyAddress.mSelector = kAudioDevicePropertyPreferredChannelLayout;
propertyAddress.mScope = kAudioDevicePropertyScopeOutput;
if(AudioObjectHasProperty(outputDeviceID, &propertyAddress)) {
err = AudioObjectGetPropertyDataSize(outputDeviceID, &propertyAddress, 0, nil, &dataSize);
AudioChannelLayout *preferredChannelLayout = (AudioChannelLayout *)(malloc(dataSize));
err = AudioObjectGetPropertyData(outputDeviceID, &propertyAddress, 0, nil, &dataSize, preferredChannelLayout);
const AudioChannelLayout *specifier [1] = { preferredChannelLayout };
// Not all channel layouts can be mapped, so handle failure with a generic mapping
dataSize = (UInt32)sizeof(deviceChannelMap);
err = AudioFormatGetProperty(kAudioFormatProperty_ChannelMap, sizeof(specifier), specifier, &dataSize, deviceChannelMap);
if(noErr != err) {
// Just use a channel map that makes sense
for(UInt32 i = 0; i < deviceFormat.mChannelsPerFrame; ++i)
deviceChannelMap[i] = i;
}
free(preferredChannelLayout), preferredChannelLayout = nil;
}
else {
// Just use a channel map that makes sense
for(UInt32 i = 0; i < deviceFormat.mChannelsPerFrame; ++i)
deviceChannelMap[i] = i;
}
}
///Seems some 3rd party devices return incorrect stuff...or I just don't like noninterleaved data.
deviceFormat.mFormatFlags &= ~kLinearPCMFormatFlagIsNonInterleaved;
// deviceFormat.mFormatFlags &= ~kLinearPCMFormatFlagIsFloat;
@ -199,6 +273,14 @@ static OSStatus Sound_Renderer(void *inRefCon, AudioUnitRenderActionFlags *ioAc
0,
&deviceFormat,
size);
size = sizeof(deviceChannelMap);
err = AudioUnitSetProperty(outputUnit,
kAudioOutputUnitProperty_ChannelMap,
kAudioUnitScope_Output,
0,
deviceChannelMap,
size);
//setup render callbacks
renderCallback.inputProc = Sound_Renderer;