CAAudioChannelLayout.h

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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);

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;

    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