PublicUtility/CAAudioChannelLayout.cpp
/* |
File: CAAudioChannelLayout.cpp |
Abstract: CAAudioChannelLayout.h |
Version: 1.01 |
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*/ |
//============================================================================= |
// Includes |
//============================================================================= |
// Self Include |
#include "CAAudioChannelLayout.h" |
#include "CAAutoDisposer.h" |
#include <stdlib.h> |
#include <string.h> |
//============================================================================= |
// CAAudioChannelLayout |
//============================================================================= |
AudioChannelLayout* CAAudioChannelLayout::Create(UInt32 inNumberChannelDescriptions) |
{ |
UInt32 theSize = CalculateByteSize(inNumberChannelDescriptions); |
AudioChannelLayout* theAnswer = static_cast<AudioChannelLayout*>(CA_calloc(1, theSize)); |
if(theAnswer != NULL) |
{ |
SetAllToUnknown(*theAnswer, inNumberChannelDescriptions); |
} |
return theAnswer; |
} |
void CAAudioChannelLayout::Destroy(AudioChannelLayout* inChannelLayout) |
{ |
free(inChannelLayout); |
} |
void CAAudioChannelLayout::SetAllToUnknown(AudioChannelLayout& outChannelLayout, UInt32 inNumberChannelDescriptions) |
{ |
outChannelLayout.mChannelLayoutTag = kAudioChannelLayoutTag_UseChannelDescriptions; |
outChannelLayout.mChannelBitmap = 0; |
outChannelLayout.mNumberChannelDescriptions = inNumberChannelDescriptions; |
for(UInt32 theChannelIndex = 0; theChannelIndex < inNumberChannelDescriptions; ++theChannelIndex) |
{ |
outChannelLayout.mChannelDescriptions[theChannelIndex].mChannelLabel = kAudioChannelLabel_Unknown; |
outChannelLayout.mChannelDescriptions[theChannelIndex].mChannelFlags = 0; |
outChannelLayout.mChannelDescriptions[theChannelIndex].mCoordinates[0] = 0; |
outChannelLayout.mChannelDescriptions[theChannelIndex].mCoordinates[1] = 0; |
outChannelLayout.mChannelDescriptions[theChannelIndex].mCoordinates[2] = 0; |
} |
} |
bool operator== (const AudioChannelLayout &x, const AudioChannelLayout &y) |
{ |
// compare based on the number of channel descriptions present |
// (this may be too strict a comparison if all you care about are matching layout tags) |
UInt32 theSize1 = CAAudioChannelLayout::CalculateByteSize(x.mNumberChannelDescriptions); |
UInt32 theSize2 = CAAudioChannelLayout::CalculateByteSize(y.mNumberChannelDescriptions); |
if (theSize1 != theSize2) |
return false; |
return !memcmp (&x, &y, theSize1); |
} |
bool operator!= (const AudioChannelLayout &x, const AudioChannelLayout &y) |
{ |
return !(x == y); |
} |
// counting the one bits in a word |
inline UInt32 CountOnes(UInt32 x) |
{ |
// secret magic algorithm for counting bits in a word. |
UInt32 t; |
x = x - ((x >> 1) & 0x55555555); |
t = ((x >> 2) & 0x33333333); |
x = (x & 0x33333333) + t; |
x = (x + (x >> 4)) & 0x0F0F0F0F; |
x = x + (x << 8); |
x = x + (x << 16); |
return x >> 24; |
} |
UInt32 CAAudioChannelLayout::NumberChannels (const AudioChannelLayout& inLayout) |
{ |
if (inLayout.mChannelLayoutTag == kAudioChannelLayoutTag_UseChannelDescriptions) |
return inLayout.mNumberChannelDescriptions; |
if (inLayout.mChannelLayoutTag == kAudioChannelLayoutTag_UseChannelBitmap) |
return CountOnes (inLayout.mChannelBitmap); |
return AudioChannelLayoutTag_GetNumberOfChannels(inLayout.mChannelLayoutTag); |
} |
void CAShowAudioChannelLayout (FILE* file, const AudioChannelLayout *layout) |
{ |
if (layout == NULL) |
{ |
fprintf (file, "\tNULL layout\n"); |
return; |
} |
fprintf (file, "\tTag=0x%X, ", (int)layout->mChannelLayoutTag); |
if (layout->mChannelLayoutTag == kAudioChannelLayoutTag_UseChannelBitmap) |
fprintf (file, "Using Bitmap:0x%X\n", (int)layout->mChannelBitmap); |
else { |
fprintf (file, "Num Chan Descs=%d\n", (int)layout->mNumberChannelDescriptions); |
const AudioChannelDescription *desc = layout->mChannelDescriptions; |
for (unsigned int i = 0; i < layout->mNumberChannelDescriptions; ++i, ++desc) { |
fprintf (file, "\t\tLabel=%d, Flags=0x%X, ", (int)desc->mChannelLabel, (int)desc->mChannelFlags); |
fprintf (file, "[az=%f,el=%f,dist=%f]\n", desc->mCoordinates[0], desc->mCoordinates[1], desc->mCoordinates[2]); |
} |
} |
} |
Copyright © 2012 Apple Inc. All Rights Reserved. Terms of Use | Privacy Policy | Updated: 2012-07-17