merge from 2.0-ongoing @ 3581

git-svn-id: svn://localhost/ardour2/branches/3.0@3711 d708f5d6-7413-0410-9779-e7cbd77b26cf

3 files changed, 42 insertions, 1 deletions

diff --git a/libs/appleutility/CAAudioUnit.cpp b/libs/appleutility/CAAudioUnit.cpp
index 9244877d29..aaf57f233d 100644
--- a/libs/appleutility/CAAudioUnit.cpp
+++ b/libs/appleutility/CAAudioUnit.cpp
@@ -328,6 +328,46 @@ bool		CAAudioUnit::CanDo (	int 				inChannelsIn,
 	return ValidateChannelPair (inChannelsIn, inChannelsOut, info.mChanInfo, (dataSize / sizeof (AUChannelInfo)));
 }
 
+int    CAAudioUnit::GetChannelInfo (AUChannelInfo** chaninfo, UInt32& cnt)
+{
+	// this is the default assumption of an audio effect unit
+	Boolean* isWritable = 0;
+	UInt32	dataSize = 0;
+		// lets see if the unit has any channel restrictions
+	OSStatus result = AudioUnitGetPropertyInfo (AU(),
+						    kAudioUnitProperty_SupportedNumChannels,
+						    kAudioUnitScope_Global, 0,
+						    &dataSize, isWritable); //don't care if this is writable
+	
+	// if this property is NOT implemented an FX unit
+	// is expected to deal with same channel valance in and out
+	
+	if (result) 
+	{
+		if (Comp().Desc().IsEffect()) 
+		{
+			return 1;
+		}
+		else 
+		{
+			// the au should either really tell us about this
+			// or we will assume the worst
+			return -1;
+		}
+	}
+
+	*chaninfo = (AUChannelInfo*) malloc (dataSize);
+	cnt = dataSize / sizeof (AUChannelInfo);
+
+	result = GetProperty (kAudioUnitProperty_SupportedNumChannels,
+			      kAudioUnitScope_Global, 0,
+			      *chaninfo, &dataSize);
+
+	if (result) { return -1; }
+	return 0;
+}
+
+
 bool	CAAudioUnit::ValidateChannelPair (int 				inChannelsIn, 
 										int 				inChannelsOut,
 										const AUChannelInfo * info,
diff --git a/libs/appleutility/CAAudioUnit.h b/libs/appleutility/CAAudioUnit.h
index 6bc31bf30b..810b81be2f 100644
--- a/libs/appleutility/CAAudioUnit.h
+++ b/libs/appleutility/CAAudioUnit.h
@@ -218,6 +218,7 @@ public:
 	bool					HasChannelLayouts (AudioUnitScope 		inScope, 
 											AudioUnitElement 		inEl) const;
 		
+	int                                     GetChannelInfo (AUChannelInfo** chaninfo, UInt32& cnt);
 	bool					GetChannelLayouts (AudioUnitScope 		inScope,
 									AudioUnitElement 				inEl,
 									ChannelTagVector				&outChannelVector) const;
diff --git a/libs/appleutility/SConscript b/libs/appleutility/SConscript
index bddca04032..c4f65ec81e 100644
--- a/libs/appleutility/SConscript
+++ b/libs/appleutility/SConscript
@@ -7,7 +7,7 @@ import glob
 appleutility_files = glob.glob('*.cpp') 
 
 Import('env install_prefix')
-appleutility = env.Copy()
+appleutility = env.Clone()
 
 appleutility.Append(LINKFLAGS='-framework AudioToolbox')
 appleutility.Append(LINKFLAGS='-framework AudioUnit')