CAAudioChannelLayout.h

/*
     File: CAAudioChannelLayout.h 
 Abstract:  Part of CoreAudio Utility Classes  
  Version: 1.01 
  
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*/
#if !defined(__CAAudioChannelLayout_h__)
#define __CAAudioChannelLayout_h__

//=============================================================================
//	Includes
//=============================================================================

//	System Includes
#if !defined(__COREAUDIO_USE_FLAT_INCLUDES__)
	#include <CoreAudio/CoreAudioTypes.h>
	#include <CoreFoundation/CoreFoundation.h>
#else
	#include <CoreAudioTypes.h>
	#include <CoreFoundation.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "CADebugMacros.h"
#include "CAAutoDisposer.h"

#if !HAL_Build
	#include "CAReferenceCounted.h"
#endif

//=============================================================================
//	CAAudioChannelLayout
//=============================================================================

bool	operator== (const AudioChannelLayout &x, const AudioChannelLayout &y);
bool	operator!= (const AudioChannelLayout &x, const AudioChannelLayout &y);

extern "C" void 	CAShowAudioChannelLayout (FILE* file, const AudioChannelLayout *layout);

class CAAudioChannelLayout
{
//	static Construction/Destruction
public:
	static AudioChannelLayout*	Create(UInt32 inNumberChannelDescriptions);
	static void					Destroy(AudioChannelLayout* inChannelLayout);
	static UInt32				CalculateByteSize(UInt32 inNumberChannelDescriptions) { 
									return OffsetOf32(AudioChannelLayout, mChannelDescriptions) + inNumberChannelDescriptions * SizeOf32(AudioChannelDescription);
								}
	static void					SetAllToUnknown(AudioChannelLayout& outChannelLayout, UInt32 inNumberChannelDescriptions);
	static UInt32				NumberChannels(const AudioChannelLayout& inLayout);
	
#if !HAL_Build
// object methods	
public:
								CAAudioChannelLayout ();

								CAAudioChannelLayout (UInt32 inNumberChannels, bool inChooseSurround);
									// if inChooseSurround is false, then symmetrical speaker arrangements
									// are chosen in place of surround layouts if there is a choice
									// This call chooses layouts based on the expected defaults in 
									// AudioUnit usage
								CAAudioChannelLayout (AudioChannelLayoutTag inTag);
								CAAudioChannelLayout (const CAAudioChannelLayout &c);
								CAAudioChannelLayout (const AudioChannelLayout* inChannelLayout);
								~CAAudioChannelLayout();
	
	CAAudioChannelLayout&		operator= (const AudioChannelLayout* inChannelLayout);
	CAAudioChannelLayout&		operator= (const CAAudioChannelLayout& c);
	bool						operator== (const CAAudioChannelLayout &c) const;
	bool						operator!= (const CAAudioChannelLayout &c) const;

	void						SetWithTag(AudioChannelLayoutTag inTag);

	bool						IsValid() const { return NumberChannels() > 0; }
	UInt32						Size() const { return mLayout ? mLayout->Size() : 0; }
	
	UInt32						NumberChannels() const { return mLayout ? mLayout->NumberChannels() : 0; }
	
	AudioChannelLayoutTag		Tag() const { return Layout().mChannelLayoutTag; }
	const AudioChannelLayout&	Layout() const { return mLayout->Layout(); }
	operator const AudioChannelLayout *() const { return &Layout(); }
	
	void						Print () const { Print (stdout); }
	void						Print (FILE* file) const;

	OSStatus					Save (CFPropertyListRef *outData) const;
	OSStatus					Restore (CFPropertyListRef &inData);
	
private:
	class RefCountedLayout : public CAReferenceCounted {
		void *	operator new(size_t /* size */, size_t aclSize)
		{
			return CA_malloc(sizeof(RefCountedLayout) - sizeof(AudioChannelLayout) + aclSize);
		}
		
		void	operator delete(void *mem)
		{
			free(mem);
		}
		
		
		RefCountedLayout(UInt32 inDataSize) :
			mByteSize(inDataSize)
		{ 
			memset(&mACL, 0, inDataSize);
		}
		
	public:
		static RefCountedLayout *CreateWithNumberChannelDescriptions(unsigned nChannels) {
								size_t size = CAAudioChannelLayout::CalculateByteSize(nChannels);
								return new(size) RefCountedLayout(size);
							}

		static RefCountedLayout *CreateWithLayout(const AudioChannelLayout *layout) {
								size_t size = CAAudioChannelLayout::CalculateByteSize(layout->mNumberChannelDescriptions);
								RefCountedLayout *acl = new(size) RefCountedLayout(size);
								memcpy(&acl->mACL, layout, size);
								return acl;
							}
		static RefCountedLayout *CreateWithLayoutTag(AudioChannelLayoutTag layoutTag) {
								RefCountedLayout *acl = CreateWithNumberChannelDescriptions(0);
								acl->mACL.mChannelLayoutTag = layoutTag;
								return acl;
							}
	
		const AudioChannelLayout & 	Layout() const { return mACL; }
		
		UInt32						Size () const { return mByteSize; }
		
		UInt32						NumberChannels() { return CAAudioChannelLayout::NumberChannels(Layout()); }
		
	private:
		const UInt32		mByteSize;
		AudioChannelLayout 	mACL;
		// * * * mACL is variable length and thus must be last * * *
		
			// only the constructors can change the actual state of the layout
		friend CAAudioChannelLayout::CAAudioChannelLayout (UInt32 inNumberChannels, bool inChooseSurround);
		friend OSStatus CAAudioChannelLayout::Restore (CFPropertyListRef &inData);
		friend CAAudioChannelLayout& CAAudioChannelLayout::operator= (const AudioChannelLayout* inChannelLayout);
		friend void CAAudioChannelLayout::SetWithTag(AudioChannelLayoutTag inTag);
		
		AudioChannelLayout * 	GetLayout() { return &mACL; }
	
	private:
		// prohibited methods: private and unimplemented.
		RefCountedLayout();
		RefCountedLayout(const RefCountedLayout& c);
		RefCountedLayout& operator=(const RefCountedLayout& c);
	};
	
	RefCountedLayout		*mLayout;
#endif	//	HAL_Build

};

#endif