add isStereo to OMixerInterface to gather whether a given channel is a stereo or mono channel

3 files changed, 30 insertions, 4 deletions

diff --git a/libopie2/examples/opiemm/osoundsystemdemo/osoundsystemdemo.cpp b/libopie2/examples/opiemm/osoundsystemdemo/osoundsystemdemo.cpp
index b522441..f74a1b9 100644
--- a/libopie2/examples/opiemm/osoundsystemdemo/osoundsystemdemo.cpp
+++ b/libopie2/examples/opiemm/osoundsystemdemo/osoundsystemdemo.cpp
@@ -54,9 +54,10 @@ int main( int argc, char** argv )
     QStringList channels = mixer->allChannels();
 
     for ( QStringList::Iterator it = channels.begin(); it != channels.end(); ++it )
     {
-        odebug << "OSSDEMO: Mixer has channel " <<  *it << "" << oendl;
+        bool stereo = mixer->isStereo( *it );
+        odebug << "OSSDEMO: Mixer has channel " << *it << ( stereo ? "[stereo]" : "[mono]" ) << oendl;
         odebug << "OSSDEMO:              +--- volume " << ( mixer->volume( *it ) & 0xff )
                << " (left) | " << ( mixer->volume( *it ) >> 8 ) << " (right)" << oendl;
     }
 
diff --git a/libopie2/opiemm/osoundsystem.cpp b/libopie2/opiemm/osoundsystem.cpp
index 13b26e6..09fd28f 100644
--- a/libopie2/opiemm/osoundsystem.cpp
+++ b/libopie2/opiemm/osoundsystem.cpp
@@ -193,9 +193,9 @@ void OMixerInterface::init()
     // open the device
     _fd = ::open( name(), O_RDWR );
     if ( _fd == -1 )
     {
-        owarn << "OMixerInterface::init(): Can't open mixer." << oendl;
+        owarn << "OMixerInterface::init(): Can't open mixer " << name() << oendl;
         return;
     }
 
     // construct the device capabilities
@@ -238,8 +238,14 @@ void OMixerInterface::init()
         if ( devmask & ( 1 << SOUND_MIXER_OGAIN ) )     _channels.insert( "RecOutputGain", SOUND_MIXER_OGAIN );
         //odebug << "recmask available and constructed." << oendl;
     }
 
+    devmask = 0;
+    if ( ioctl( _fd, SOUND_MIXER_READ_STEREODEVS, &devmask ) != -1 )
+    {
+        odebug << "stereomask = " << devmask << oendl;
+    }
+
 /*    ChannelIterator it;
     for ( it = _channels.begin(); it != _channels.end(); ++it )
     {
         odebug << "Channel " <<  it.key() << " available (bit " << it.data() << ")" << oendl;
@@ -274,14 +280,29 @@ QStringList OMixerInterface::playChannels() const
     return QStringList();
 }
 
 
-bool OMixerInterface::hasChannel( const QString& channel )
+bool OMixerInterface::hasChannel( const QString& channel ) const
 {
     return _channels.contains( channel );
 }
 
 
+bool OMixerInterface::isStereo( const QString& channel ) const
+{
+    bool result = false;
+    if ( _channels.contains( channel ) )
+    {
+        int devmask = 0;
+        if ( ioctl( _fd, SOUND_MIXER_READ_STEREODEVS, &devmask ) != -1 )
+        {
+            result = devmask & ( 1 << _channels[channel] );
+        }
+    }
+    return result;
+}
+
+
 void OMixerInterface::setVolume( const QString& channel, int left, int right )
 {
     int volume = left;
     volume |= ( right == -1 ) ? left << 8 : right << 8;
diff --git a/libopie2/opiemm/osoundsystem.h b/libopie2/opiemm/osoundsystem.h
index bd69114..ac7a5a7 100644
--- a/libopie2/opiemm/osoundsystem.h
+++ b/libopie2/opiemm/osoundsystem.h
@@ -201,9 +201,13 @@ class OMixerInterface : public QObject
 
     /**
      * @returns true, if @a channel exists.
      */
-    bool hasChannel( const QString& channel );
+    bool hasChannel( const QString& channel ) const;
+    /**
+     * @returns true, if @a channel is stereo.
+     */
+    bool isStereo( const QString& channel ) const;
 
     /**
      * Set the @a left and @a right volumes for @a channel.
      * If no value for right is given, the value for left is taken for that.