introduce a gain cache for non active sources to allow changing of gain without activating them, and to avoid gain value beeing reset to 0.0 each time enable is cycled.

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@3814 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/add-ons/media/media-add-ons/mixer/AudioMixer.cpp

@@ -976,22 +976,15 @@ AudioMixer::SetParameterValue(int32 id, bigtime_t when,
 			if (size != sizeof(int32))
 				goto err;
 			if (static_cast<const int32 *>(value)[0]) {
-				output->AddOutputChannelSource(PARAM_CHAN(id), PARAM_SRC(id), 0.0);
+				output->AddOutputChannelSource(PARAM_CHAN(id), PARAM_SRC(id));
 			} else {
 				output->RemoveOutputChannelSource(PARAM_CHAN(id), PARAM_SRC(id));
 			}
-			// after adding/removing sources, reset gain to 0.0
-			float nullgain = 0.0;
-			BroadcastNewParameterValue(when, PARAM_SRC_GAIN(PARAM(id), PARAM_CHAN(id), PARAM_SRC(id)), &nullgain, sizeof(nullgain));
 		}
 		if (PARAM_IS_SRC_GAIN(id)) {
 			if (size != sizeof(float))
 				goto err;
-			if (!output->SetOutputChannelSourceGain(PARAM_CHAN(id), PARAM_SRC(id), PERCENT_TO_GAIN(static_cast<const float *>(value)[0]))) {
+			output->SetOutputChannelSourceGain(PARAM_CHAN(id), PARAM_SRC(id), PERCENT_TO_GAIN(static_cast<const float *>(value)[0]));
-				// gain setting failed, reset to 0.0
-				float nullgain = 0.0;
-				BroadcastNewParameterValue(when, PARAM_SRC_GAIN(PARAM(id), PARAM_CHAN(id), PARAM_SRC(id)), &nullgain, sizeof(nullgain));
-			}
 		}
 	} else {
 		MixerInput *input;

src/add-ons/media/media-add-ons/mixer/MixerOutput.cpp

@@ -75,7 +75,11 @@ MixerOutput::UpdateOutputChannels()
 		fOutputChannelInfo[i].source_count = 1;
 		fOutputChannelInfo[i].source_gain[0] = 1.0;
 		fOutputChannelInfo[i].source_type[0] = fOutputChannelInfo[i].channel_type;
+		// all the cached values are 0.0 for a new channel
+		for (int j = 0; j < MAX_CHANNEL_TYPES; j++)
+			fOutputChannelInfo[i].source_gain_cache[j] = 0.0;
 	}
+
 	AssignDefaultSources();
 	
 	// apply old gains and sources, overriding the 1.0 gain defaults for the old channels
@@ -89,6 +93,9 @@ MixerOutput::UpdateOutputChannels()
 						fOutputChannelInfo[i].source_gain[k] == oldInfo[j].source_gain[k];
 						fOutputChannelInfo[i].source_type[k] == oldInfo[j].source_type[k];
 					}
+					// also copy the old gain cache
+					for (int k = 0; k < MAX_CHANNEL_TYPES; k++)
+						fOutputChannelInfo[i].source_gain_cache[k] = oldInfo[j].source_gain_cache[k];
 					break;
 				}
 			}
@@ -240,16 +247,20 @@ MixerOutput::SetOutputChannelGain(int channel, float gain)
 }
 
 void
-MixerOutput::AddOutputChannelSource(int channel, int source_type, float source_gain)
+MixerOutput::AddOutputChannelSource(int channel, int source_type)
 {
 	if (channel < 0 || channel >= fOutputChannelCount)
 		return;
+	if (source_type < 0 || source_type >= MAX_CHANNEL_TYPES)
+		return;
 	if (fOutputChannelInfo[channel].source_count == MAX_SOURCE_ENTRIES)
 		return;
 	for (int i = 0; i < fOutputChannelInfo[channel].source_count; i++) {
 		if (fOutputChannelInfo[channel].source_type[i] == source_type)
 			return;
 	}
+	// when adding a new source, use the current gain value from cache
+	float source_gain = fOutputChannelInfo[channel].source_gain_cache[source_type];
 	fOutputChannelInfo[channel].source_type[fOutputChannelInfo[channel].source_count] = source_type;
 	fOutputChannelInfo[channel].source_gain[fOutputChannelInfo[channel].source_count] = source_gain;
 	fOutputChannelInfo[channel].source_count++;
@@ -262,6 +273,9 @@ MixerOutput::RemoveOutputChannelSource(int channel, int source_type)
 		return;
 	for (int i = 0; i < fOutputChannelInfo[channel].source_count; i++) {
 		if (fOutputChannelInfo[channel].source_type[i] == source_type) {
+			// when removing a source, save the current gain value into the cache
+			fOutputChannelInfo[channel].source_gain_cache[source_type] = fOutputChannelInfo[channel].source_gain[i];
+			// remove the entry
 			fOutputChannelInfo[channel].source_type[i] = fOutputChannelInfo[channel].source_type[fOutputChannelInfo[channel].source_count - 1];
 			fOutputChannelInfo[channel].source_gain[i] = fOutputChannelInfo[channel].source_gain[fOutputChannelInfo[channel].source_count - 1];
 			fOutputChannelInfo[channel].source_count--;
@@ -270,18 +284,22 @@ MixerOutput::RemoveOutputChannelSource(int channel, int source_type)
 	}
 }
 
-bool
+void
 MixerOutput::SetOutputChannelSourceGain(int channel, int source_type, float source_gain)
 {
 	if (channel < 0 || channel >= fOutputChannelCount)
-		return false;
+		return;
+	// set gain for active source
 	for (int i = 0; i < fOutputChannelInfo[channel].source_count; i++) {
 		if (fOutputChannelInfo[channel].source_type[i] == source_type) {
 			fOutputChannelInfo[channel].source_gain[i] = source_gain;
-			return true;
+			return;
 		}
 	}
-	return false;
+	// we don't have an active source of that type, save gain in cache
+	if (source_type < 0 || source_type >= MAX_CHANNEL_TYPES)
+		return;
+	fOutputChannelInfo[channel].source_gain_cache[source_type] = source_gain;
 }
 
 float
@@ -289,12 +307,16 @@ MixerOutput::GetOutputChannelSourceGain(int channel, int source_type)
 {
 	if (channel < 0 || channel >= fOutputChannelCount)
 		return 0.0;
+	// get gain for active source
 	for (int i = 0; i < fOutputChannelInfo[channel].source_count; i++) {
 		if (fOutputChannelInfo[channel].source_type[i] == source_type) {
 			return fOutputChannelInfo[channel].source_gain[i];
 		}
 	}
-	return 0.0;
+	// we don't have an active source of that type, get gain from cache
+	if (source_type < 0 || source_type >= MAX_CHANNEL_TYPES)
+		return 0.0;
+	return fOutputChannelInfo[channel].source_gain_cache[source_type];
 }
 
 bool

src/add-ons/media/media-add-ons/mixer/MixerOutput.h

@@ -10,7 +10,11 @@
  * for fast data retrieval by the MixerCore, which
  * will call GetOutputChannelSourceInfoAt() and
  * iterate through the first source_count array entries
- * for source_gain[] and source_type[]
+ * for source_gain[] and source_type[] arrays, they are
+ * index by 0 to GetOutputChannelSourceCount() - 1.
+ * To allow gain change for not active sources,
+ * we use the source_gain_cache[] array that is indexed
+ * by source_type.
  */
 
 class MixerOutput
@@ -30,9 +34,9 @@ public:
 	float	GetOutputChannelGain(int channel);
 	
 	// The Sources for each channel
-	void	AddOutputChannelSource(int channel, int source_type, float source_gain);
+	void	AddOutputChannelSource(int channel, int source_type);
 	void	RemoveOutputChannelSource(int channel, int source_type);
-	bool	SetOutputChannelSourceGain(int channel, int source_type, float source_gain);
+	void	SetOutputChannelSourceGain(int channel, int source_type, float source_gain);
 	float	GetOutputChannelSourceGain(int channel, int source_type);
 	bool	HasOutputChannelSource(int channel, int source_type);
 	
@@ -69,6 +73,7 @@ private:
 		int		source_count;
 		float	source_gain[MAX_SOURCE_ENTRIES];
 		int		source_type[MAX_SOURCE_ENTRIES];
+		float	source_gain_cache[MAX_CHANNEL_TYPES];
 	};	
 
 	MixerCore 			*fCore;