libs/appleutility/CAAudioChannelLayout.cpp

   1 /*      Copyright:      © Copyright 2005 Apple Computer, Inc. All rights reserved.
   2
   3         Disclaimer:     IMPORTANT:  This Apple software is supplied to you by Apple Computer, Inc.
   4                         ("Apple") in consideration of your agreement to the following terms, and your
   5                         use, installation, modification or redistribution of this Apple software
   6                         constitutes acceptance of these terms.  If you do not agree with these terms,
   7                         please do not use, install, modify or redistribute this Apple software.
   8
   9                         In consideration of your agreement to abide by the following terms, and subject
  10                         to these terms, Apple grants you a personal, non-exclusive license, under AppleÕs
  11                         copyrights in this original Apple software (the "Apple Software"), to use,
  12                         reproduce, modify and redistribute the Apple Software, with or without
  13                         modifications, in source and/or binary forms; provided that if you redistribute
  14                         the Apple Software in its entirety and without modifications, you must retain
  15                         this notice and the following text and disclaimers in all such redistributions of
  16                         the Apple Software.  Neither the name, trademarks, service marks or logos of
  17                         Apple Computer, Inc. may be used to endorse or promote products derived from the
  18                         Apple Software without specific prior written permission from Apple.  Except as
  19                         expressly stated in this notice, no other rights or licenses, express or implied,
  20                         are granted by Apple herein, including but not limited to any patent rights that
  21                         may be infringed by your derivative works or by other works in which the Apple
  22                         Software may be incorporated.
  23
  24                         The Apple Software is provided by Apple on an "AS IS" basis.  APPLE MAKES NO
  25                         WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED
  26                         WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  27                         PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE OR IN
  28                         COMBINATION WITH YOUR PRODUCTS.
  29
  30                         IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR
  31                         CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
  32                         GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  33                         ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION, MODIFICATION AND/OR DISTRIBUTION
  34                         OF THE APPLE SOFTWARE, HOWEVER CAUSED AND WHETHER UNDER THEORY OF CONTRACT, TORT
  35                         (INCLUDING NEGLIGENCE), STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN
  36                         ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  37 */
  38 /*=============================================================================
  39         CAAudioChannelLayout.cpp
  40
  41 =============================================================================*/
  42
  43 //=============================================================================
  44 //      Includes
  45 //=============================================================================
  46
  47 //      Self Include
  48 #include "CAAudioChannelLayout.h"
  49 #include <stdlib.h>
  50 #include <string.h>
  51
  52 //=============================================================================
  53 //      CAAudioChannelLayout
  54 //=============================================================================
  55
  56 AudioChannelLayout*     CAAudioChannelLayout::Create(UInt32 inNumberChannelDescriptions)
  57 {
  58         UInt32 theSize = CalculateByteSize(inNumberChannelDescriptions);
  59         AudioChannelLayout* theAnswer = static_cast<AudioChannelLayout*>(calloc(1, theSize));
  60         if(theAnswer != NULL)
  61         {
  62                 SetAllToUnknown(*theAnswer, inNumberChannelDescriptions);
  63         }
  64         return theAnswer;
  65 }
  66
  67 void    CAAudioChannelLayout::Destroy(AudioChannelLayout* inChannelLayout)
  68 {
  69         free(inChannelLayout);
  70 }
  71
  72 void    CAAudioChannelLayout::SetAllToUnknown(AudioChannelLayout& outChannelLayout, UInt32 inNumberChannelDescriptions)
  73 {
  74         outChannelLayout.mChannelLayoutTag = kAudioChannelLayoutTag_UseChannelDescriptions;
  75         outChannelLayout.mChannelBitmap = 0;
  76         outChannelLayout.mNumberChannelDescriptions = inNumberChannelDescriptions;
  77         for(UInt32 theChannelIndex = 0; theChannelIndex < inNumberChannelDescriptions; ++theChannelIndex)
  78         {
  79                 outChannelLayout.mChannelDescriptions[theChannelIndex].mChannelLabel = kAudioChannelLabel_Unknown;
  80                 outChannelLayout.mChannelDescriptions[theChannelIndex].mChannelFlags = 0;
  81                 outChannelLayout.mChannelDescriptions[theChannelIndex].mCoordinates[0] = 0;
  82                 outChannelLayout.mChannelDescriptions[theChannelIndex].mCoordinates[1] = 0;
  83                 outChannelLayout.mChannelDescriptions[theChannelIndex].mCoordinates[2] = 0;
  84         }
  85 }
  86
  87 bool    operator== (const AudioChannelLayout &x, const AudioChannelLayout &y)
  88 {
  89         // compare based on the number of channel descriptions present
  90         // (this may be too strict a comparison if all you care about are matching layout tags)
  91         UInt32 theSize1 = CAAudioChannelLayout::CalculateByteSize(x.mNumberChannelDescriptions);
  92         UInt32 theSize2 = CAAudioChannelLayout::CalculateByteSize(y.mNumberChannelDescriptions);
  93
  94         if (theSize1 != theSize2)
  95                 return false;
  96
  97         return !memcmp (&x, &y, theSize1);
  98 }
  99
 100 // counting the one bits in a word
 101 inline UInt32 CountOnes(UInt32 x)
 102 {
 103         // secret magic algorithm for counting bits in a word.
 104         UInt32 t;
 105         x = x - ((x >> 1) & 0x55555555);
 106         t = ((x >> 2) & 0x33333333);
 107         x = (x & 0x33333333) + t;
 108         x = (x + (x >> 4)) & 0x0F0F0F0F;
 109         x = x + (x << 8);
 110         x = x + (x << 16);
 111         return x >> 24;
 112 }
 113
 114 UInt32  CAAudioChannelLayout::NumberChannels (const AudioChannelLayout& inLayout)
 115 {
 116         if (inLayout.mChannelLayoutTag == kAudioChannelLayoutTag_UseChannelDescriptions)
 117                 return inLayout.mNumberChannelDescriptions;
 118
 119         if (inLayout.mChannelLayoutTag == kAudioChannelLayoutTag_UseChannelBitmap)
 120                 return CountOnes (inLayout.mChannelBitmap);
 121
 122         return AudioChannelLayoutTag_GetNumberOfChannels(inLayout.mChannelLayoutTag);
 123 }
 124
 125 void    CAShowAudioChannelLayout (FILE* file, const AudioChannelLayout *layout)
 126 {
 127         fprintf (file, "\tTag=0x%lX, ", layout->mChannelLayoutTag);
 128         if (layout->mChannelLayoutTag == kAudioChannelLayoutTag_UseChannelBitmap)
 129                 fprintf (file, "Using Bitmap:0x%lX\n", layout->mChannelBitmap);
 130         else {
 131                 fprintf (file, "Num Chan Descs=%ld\n", layout->mNumberChannelDescriptions);
 132                 const AudioChannelDescription *desc = layout->mChannelDescriptions;
 133                 for (unsigned int i = 0; i < layout->mNumberChannelDescriptions; ++i, ++desc) {
 134                         fprintf (file, "\t\tLabel=%ld, Flags=0x%lX, ", desc->mChannelLabel, desc->mChannelFlags);
 135                         fprintf (file, "[az=%f,el=%f,dist=%f]\n", desc->mCoordinates[0], desc->mCoordinates[1], desc->mCoordinates[2]);
 136                 }
 137         }
 138 }