Handle channel selection

Author: npostavs

src/portaudiosound.cpp

@@ -50,7 +50,9 @@ CSound::CSound( void           (*fpNewProcessCallback) ( CVector<short>& psData,
                 const QString& ) :
     CSoundBase ( "portaudio", fpNewProcessCallback, arg, strMIDISetup ),
     deviceIndex (-1),
-    deviceStream (NULL)
+    deviceStream (NULL),
+    vSelectedInputChannels ( NUM_IN_OUT_CHANNELS ),
+    vSelectedOutputChannels ( NUM_IN_OUT_CHANNELS )
 {
     pThisSound = this;
 
@@ -136,7 +138,7 @@ int CSound::Init ( const int iNewPrefMonoBufferSize )
         iPrefMonoBufferSize = iNewPrefMonoBufferSize;
     }
 
-    vecsAudioData.Init ( iPrefMonoBufferSize * 2 );
+    vecsAudioData.Init ( iPrefMonoBufferSize * NUM_IN_OUT_CHANNELS );
     if ( deviceStream && deviceIndex >= 0 )
     {
         ReinitializeDriver ( deviceIndex );
@@ -165,6 +167,82 @@ PaDeviceIndex CSound::DeviceIndexFromName (const QString& strDriverName )
     return -1;
 }
 
+int CSound::GetNumInputChannels()
+{
+    if (deviceIndex >= 0)
+    {
+        const PaDeviceInfo* deviceInfo = Pa_GetDeviceInfo ( deviceIndex );
+        return deviceInfo->maxInputChannels;
+    }
+    return CSoundBase::GetNumInputChannels();
+}
+int CSound::GetNumOutputChannels()
+{
+    if (deviceIndex >= 0)
+    {
+        const PaDeviceInfo* deviceInfo = Pa_GetDeviceInfo ( deviceIndex );
+        return deviceInfo->maxOutputChannels;
+    }
+    return CSoundBase::GetNumOutputChannels();
+}
+
+QString CSound::GetInputChannelName ( const int channel )
+{
+    if (deviceIndex >= 0)
+    {
+        const char* channelName;
+        PaError err = PaAsio_GetInputChannelName ( deviceIndex, channel, &channelName );
+        if ( err == paNoError )
+        {
+            return QString ( channelName );
+        }
+    }
+    return CSoundBase::GetInputChannelName ( channel );
+}
+QString CSound::GetOutputChannelName ( const int channel )
+{
+    if (deviceIndex >= 0)
+    {
+        const char* channelName;
+        PaError err = PaAsio_GetOutputChannelName ( deviceIndex, channel, &channelName );
+        if ( err == paNoError )
+        {
+            return QString ( channelName );
+        }
+    }
+    return CSoundBase::GetOutputChannelName ( channel );
+}
+
+void CSound::SetLeftInputChannel ( const int channel )
+{
+    if ( channel < GetNumInputChannels() )
+    {
+        vSelectedInputChannels[0] = channel;
+    }
+}
+void CSound::SetRightInputChannel ( const int channel )
+{
+    if ( channel < GetNumInputChannels() )
+    {
+        vSelectedInputChannels[1] = channel;
+    }
+}
+
+void CSound::SetLeftOutputChannel ( const int channel )
+{
+    if ( channel < GetNumOutputChannels() )
+    {
+        vSelectedOutputChannels[0] = channel;
+    }
+}
+void CSound::SetRightOutputChannel ( const int channel )
+{
+    if ( channel < GetNumOutputChannels() )
+    {
+        vSelectedOutputChannels[1] = channel;
+    }
+}
+
 QString CSound::LoadAndInitializeDriver ( QString strDriverName, bool bOpenDriverSetup )
 {
     (void) bOpenDriverSetup; // FIXME: respect this
@@ -181,10 +259,11 @@ QString CSound::ReinitializeDriver ( int devIndex )
 {
     const PaDeviceInfo* deviceInfo = Pa_GetDeviceInfo ( devIndex );
 
-    if ( deviceInfo->maxInputChannels < 2 || deviceInfo->maxOutputChannels < 2 )
+    if ( deviceInfo->maxInputChannels < NUM_IN_OUT_CHANNELS ||
+         deviceInfo->maxOutputChannels < NUM_IN_OUT_CHANNELS )
     {
         // FIXME: handle mono devices.
-        return tr ( "Less than 2 channels supported" );
+        return tr ( "Less than 2 channels not supported" );
     }
 
     if ( deviceStream != NULL )
@@ -195,18 +274,30 @@ QString CSound::ReinitializeDriver ( int devIndex )
     }
 
     PaStreamParameters paInputParams;
+    PaAsioStreamInfo asioInputInfo;
     paInputParams.device = devIndex;
-    paInputParams.channelCount = std::min (2, deviceInfo->maxInputChannels);
+    paInputParams.channelCount = std::min (NUM_IN_OUT_CHANNELS, deviceInfo->maxInputChannels);
     paInputParams.sampleFormat = paInt16;
     paInputParams.suggestedLatency = deviceInfo->defaultLowInputLatency;
-    paInputParams.hostApiSpecificStreamInfo = NULL;
+    paInputParams.hostApiSpecificStreamInfo = &asioInputInfo;
+    asioInputInfo.size = sizeof asioInputInfo;
+    asioInputInfo.hostApiType = paASIO;
+    asioInputInfo.version = 1;
+    asioInputInfo.flags = paAsioUseChannelSelectors;
+    asioInputInfo.channelSelectors = &vSelectedInputChannels[0];
 
     PaStreamParameters paOutputParams;
+    PaAsioStreamInfo asioOutputInfo;
     paOutputParams.device = devIndex;
-    paOutputParams.channelCount = std::min (2, deviceInfo->maxOutputChannels);
+    paOutputParams.channelCount = std::min (NUM_IN_OUT_CHANNELS, deviceInfo->maxOutputChannels);
     paOutputParams.sampleFormat = paInt16;
     paOutputParams.suggestedLatency = deviceInfo->defaultLowOutputLatency;
-    paOutputParams.hostApiSpecificStreamInfo = NULL;
+    paOutputParams.hostApiSpecificStreamInfo = &asioOutputInfo;
+    asioOutputInfo.size = sizeof asioOutputInfo;
+    asioOutputInfo.hostApiType = paASIO;
+    asioOutputInfo.version = 1;
+    asioOutputInfo.flags = paAsioUseChannelSelectors;
+    asioOutputInfo.channelSelectors = &vSelectedOutputChannels[0];
 
     PaError err = Pa_OpenStream ( &deviceStream,
                                   &paInputParams,
@@ -224,6 +315,8 @@ QString CSound::ReinitializeDriver ( int devIndex )
             ( Pa_GetLastHostErrorInfo () ->errorText );
     }
 
+    strCurDevName = deviceInfo->name;
+
     deviceIndex = devIndex;
     return "";
 }
@@ -249,12 +342,12 @@ int CSound::paStreamCallback(const void *input, void *output, unsigned long fram
     CVector<int16_t>& vecsAudioData = pSound->vecsAudioData;
 
     // CAPTURE ---------------------------------
-    memcpy (&vecsAudioData[0], input, sizeof (int16_t) * frameCount * 2);
+    memcpy (&vecsAudioData[0], input, sizeof (int16_t) * frameCount * NUM_IN_OUT_CHANNELS);
 
     pSound->ProcessCallback ( vecsAudioData );
 
     // PLAYBACK ------------------------------------------------------------
-    memcpy (output, &vecsAudioData[0], sizeof (int16_t) * frameCount * 2);
+    memcpy (output, &vecsAudioData[0], sizeof (int16_t) * frameCount * NUM_IN_OUT_CHANNELS);
 
     return paContinue;
 }

src/portaudiosound.h

@@ -42,6 +42,8 @@
 
 #include <portaudio.h>
 
+#define NUM_IN_OUT_CHANNELS         2 // always stereo
+
 class CSound : public CSoundBase
 {
 public:
@@ -56,6 +58,20 @@ class CSound : public CSoundBase
     virtual void Start ();
     virtual void Stop ();
 
+    virtual int     GetNumInputChannels();
+    virtual QString GetInputChannelName ( const int );
+    virtual void    SetLeftInputChannel  ( const int );
+    virtual void    SetRightInputChannel ( const int );
+    virtual int     GetLeftInputChannel()  { return vSelectedInputChannels[0]; }
+    virtual int     GetRightInputChannel() { return vSelectedInputChannels[1]; }
+
+    virtual int     GetNumOutputChannels();
+    virtual QString GetOutputChannelName ( const int );
+    virtual void    SetLeftOutputChannel  ( const int );
+    virtual void    SetRightOutputChannel ( const int );
+    virtual int     GetLeftOutputChannel()  { return vSelectedOutputChannels[0]; }
+    virtual int     GetRightOutputChannel() { return vSelectedOutputChannels[1]; }
+
 #ifdef WIN32
     // Portaudio's function for this takes a device index as a parameter.  So it
     // needs to reopen ASIO in order to get the right driver loaded.  Because of
@@ -79,6 +95,8 @@ class CSound : public CSoundBase
     PaHostApiIndex asioIndex;
     PaDeviceIndex deviceIndex;
     PaStream* deviceStream;
+    CVector<int> vSelectedInputChannels;
+    CVector<int> vSelectedOutputChannels;
     int iPrefMonoBufferSize;
     CVector<int16_t> vecsAudioData;
 };