CAAudioBufferList.cpp

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

#include "CAAudioBufferList.h"
#include "CADebugMacros.h"
#include "CALogMacros.h"
#include <stdlib.h>
#include <string.h>

//=============================================================================
//  CAAudioBufferList
//=============================================================================

AudioBufferList*    CAAudioBufferList::Create(UInt32 inNumberBuffers)
{
    UInt32 theSize = CalculateByteSize(inNumberBuffers);
    AudioBufferList* theAnswer = static_cast<AudioBufferList*>(calloc(1, theSize));
    if(theAnswer != NULL)
    {
        theAnswer->mNumberBuffers = inNumberBuffers;
    }
    return theAnswer;
}

void    CAAudioBufferList::Destroy(AudioBufferList* inBufferList)
{
    free(inBufferList);
}

UInt32  CAAudioBufferList::CalculateByteSize(UInt32 inNumberBuffers)
{
    UInt32 theSize = SizeOf32(AudioBufferList) - SizeOf32(AudioBuffer);
    theSize += inNumberBuffers * SizeOf32(AudioBuffer);
    return theSize;
}

UInt32  CAAudioBufferList::GetTotalNumberChannels(const AudioBufferList& inBufferList)
{
    UInt32 theAnswer = 0;
    
    for(UInt32 theIndex = 0; theIndex < inBufferList.mNumberBuffers; ++theIndex)
    {
        theAnswer += inBufferList.mBuffers[theIndex].mNumberChannels;
    }
    
    return theAnswer;
}

bool    CAAudioBufferList::GetBufferForChannel(const AudioBufferList& inBufferList, UInt32 inChannel, UInt32& outBufferNumber, UInt32& outBufferChannel)
{
    bool theAnswer = false;
    UInt32 theIndex = 0;
    
    while((theIndex < inBufferList.mNumberBuffers) && (inChannel >= inBufferList.mBuffers[theIndex].mNumberChannels))
    {
        inChannel -= inBufferList.mBuffers[theIndex].mNumberChannels;
        ++theIndex;
    }
    
    if(theIndex < inBufferList.mNumberBuffers)
    {
        outBufferNumber = theIndex;
        outBufferChannel = inChannel;
        theAnswer = true;
    }
    
    return theAnswer;
}

void    CAAudioBufferList::Clear(AudioBufferList& outBufferList)
{
    //  assumes that "0" is actually the 0 value for this stream format
    for(UInt32 theBufferIndex = 0; theBufferIndex < outBufferList.mNumberBuffers; ++theBufferIndex)
    {
        if(outBufferList.mBuffers[theBufferIndex].mData != NULL)
        {
            memset(outBufferList.mBuffers[theBufferIndex].mData, 0, outBufferList.mBuffers[theBufferIndex].mDataByteSize);
        }
    }
}

void    CAAudioBufferList::Copy(const AudioBufferList& inSource, UInt32 inStartingSourceChannel, AudioBufferList& outDestination, UInt32 inStartingDestinationChannel)
{
    //  This is a brute force copy method that can handle ABL's that have different buffer layouts
    //  This means that this method is probably not the fastest way to do this for all cases.
    //  This method also assumes that both the source and destination sample formats are Float32

    UInt32 theInputChannel = inStartingSourceChannel;
    UInt32 theNumberInputChannels = GetTotalNumberChannels(inSource);
    UInt32 theOutputChannel = inStartingDestinationChannel;
    UInt32 theNumberOutputChannels = GetTotalNumberChannels(outDestination);
    
    UInt32 theInputBufferIndex = 0;
    UInt32 theInputBufferChannel = 0;
    UInt32 theOutputBufferIndex = 0;
    UInt32 theOutputBufferChannel = 0;
    while((theInputChannel < theNumberInputChannels) && (theOutputChannel < theNumberOutputChannels))
    {
        GetBufferForChannel(inSource, theInputChannel, theInputBufferIndex, theInputBufferChannel);
        
        GetBufferForChannel(inSource, theOutputChannel, theOutputBufferIndex, theOutputBufferChannel);
        
        CopyChannel(inSource.mBuffers[theInputBufferIndex], theInputBufferChannel, outDestination.mBuffers[theOutputBufferIndex], theOutputBufferChannel);
        
        ++theInputChannel;
        ++theOutputChannel;
    }
}

void    CAAudioBufferList::CopyChannel(const AudioBuffer& inSource, UInt32 inSourceChannel, AudioBuffer& outDestination, UInt32 inDestinationChannel)
{
    //  set up the stuff for the loop
    UInt32 theNumberFramesToCopy = outDestination.mDataByteSize / (outDestination.mNumberChannels * SizeOf32(Float32));
    const Float32* theSource = static_cast<const Float32*>(inSource.mData);
    Float32* theDestination = static_cast<Float32*>(outDestination.mData);
    
    //  loop through the data and copy the samples
    while(theNumberFramesToCopy > 0)
    {
        //  copy the data
        theDestination[inDestinationChannel] = theSource[inSourceChannel];
        
        //  adjust the pointers
        --theNumberFramesToCopy;
        theSource += inSource.mNumberChannels;
        theDestination += outDestination.mNumberChannels;
    }
}

void    CAAudioBufferList::Sum(const AudioBufferList& inSourceBufferList, AudioBufferList& ioSummedBufferList)
{
    //  assumes that the buffers are Float32 samples and the listst have the same layout
    //  this is a lame algorithm, by the way. it could at least be unrolled a couple of times
    for(UInt32 theBufferIndex = 0; theBufferIndex < ioSummedBufferList.mNumberBuffers; ++theBufferIndex)
    {
        Float32* theSourceBuffer = static_cast<Float32*>(inSourceBufferList.mBuffers[theBufferIndex].mData);
        Float32* theSummedBuffer = static_cast<Float32*>(ioSummedBufferList.mBuffers[theBufferIndex].mData);
        UInt32 theNumberSamplesToMix = ioSummedBufferList.mBuffers[theBufferIndex].mDataByteSize / SizeOf32(Float32);
        if((theSourceBuffer != NULL) && (theSummedBuffer != NULL) && (theNumberSamplesToMix > 0))
        {
            while(theNumberSamplesToMix > 0)
            {
                *theSummedBuffer += *theSourceBuffer;
                ++theSummedBuffer;
                ++theSourceBuffer;
                --theNumberSamplesToMix;
            }
        }
    }
}

bool    CAAudioBufferList::HasData(AudioBufferList& inBufferList)
{
    bool hasData = false;
    for(UInt32 theBufferIndex = 0; !hasData && (theBufferIndex < inBufferList.mNumberBuffers); ++theBufferIndex)
    {
        if(inBufferList.mBuffers[theBufferIndex].mData != NULL)
        {
            UInt32* theBuffer = (UInt32*)inBufferList.mBuffers[theBufferIndex].mData;
            UInt32 theNumberSamples = inBufferList.mBuffers[theBufferIndex].mDataByteSize / SizeOf32(UInt32);
            for(UInt32 theSampleIndex = 0; !hasData && (theSampleIndex < theNumberSamples); ++theSampleIndex)
            {
                hasData = theBuffer[theSampleIndex] != 0;
            }
        }
    }
    return hasData;
}

#if CoreAudio_Debug
void    CAAudioBufferList::PrintToLog(const AudioBufferList& inBufferList)
{
    PrintInt("  Number streams: ", inBufferList.mNumberBuffers);
    
    for(UInt32 theIndex = 0; theIndex < inBufferList.mNumberBuffers; ++theIndex)
    {
        PrintIndexedInt("  Channels in stream", theIndex + 1, inBufferList.mBuffers[theIndex].mNumberChannels);
        PrintIndexedInt("  Buffer size of stream", theIndex + 1, inBufferList.mBuffers[theIndex].mDataByteSize);
    }
}
#endif

AudioBufferList CAAudioBufferList::sEmptyBufferList = { 0, { { 0, 0, NULL } } };