/*

    File:       uLawDecompressor.c

    Contains    µLaw 2:1 Decompression Sound Component

    Written by: Jim Reekes

    Copyright:  © 1991-1998 by Apple Computer, Inc., all rights reserved.

*/

#if defined(_MSC_VER) && !defined(__MWERKS__) 

#pragma warning(disable:4229)       // ignore anachronism used: modifiers on data are ignored

#endif

#include <MacTypes.h>

#include <Errors.h>

#include <Endian.h>

#include <MacMemory.h>

#include <Resources.h>

#include <Components.h>

#include <Sound.h>

#include <MoviesFormat.h>

#if !TARGET_OS_MAC

#include "QTML.h"

#endif

#include "uLawCodec.h"

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//          Constants

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

#define kInputFormat        kCodecFormat                /* required input format */

#define kOutputFormat       k16BitNativeEndianFormat    /* decompressors must output native samples */

enum {

    kOutputSampleSize       = 16,                           /* size of output samples */

    kOutputBufferBytes      = (kMaxOutputSamples * (kOutputSampleSize/8) * 2)       /* room for 16-bit stereo data */

};

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//          types

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

#if PRAGMA_STRUCT_ALIGN

    #pragma options align=mac68k

#elif PRAGMA_STRUCT_PACKPUSH

    #pragma pack(push, 2)

#elif PRAGMA_STRUCT_PACK

    #pragma pack(2)

#endif

// Keep your data long word aligned for best performance

typedef struct {

    ComponentInstance   sourceComponent;    /* who to call for more source data */

    SoundComponentDataPtr sourceDataPtr;    /* pointer to source data descriptor */

    SoundComponentData  outputData;         /* local data descriptor record */

    SoundSource         sourceID;

    long                maxFrames;          /* max frames we can output, considering stereo */

    long                outputBufferSamples; /* no. samples in output buffer */

    CompressionInfo     compInfo;           /* info about compressor */

    Handle              ulawTableHandle;    /* resource handle to ulaw table */

    short               *ulawTable;         /* pointer to ulaw table */

    Byte                buffer[kOutputBufferBytes]; /* buffer space */

#if !TARGET_OS_MAC

    QTMLMutex           interruptMutex;     /* prevent (if necessary) the app and interrupt killing eachother */

#endif

} ULawDecompGlobals, *ULawDecompGlobalsPtr;

typedef struct {

    AudioFormatAtom     formatData;

    AudioEndianAtom     endianData;

    AudioTerminatorAtom terminatorData;

} AudioDecompressionAtom, *AudioDecompressionAtomPtr, **AudioDecompressionAtomHandle;

#if PRAGMA_STRUCT_ALIGN

    #pragma options align=reset

#elif PRAGMA_STRUCT_PACKPUSH

    #pragma pack(pop)

#elif PRAGMA_STRUCT_PACK

    #pragma pack()

#endif

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//          prototypes

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

static OSErr                GetDecompressionParams(ULawDecompGlobalsPtr globals, AudioDecompressionAtomHandle *params);

static OSErr                SetDecompressionParams(ULawDecompGlobalsPtr globals, UserDataAtom *atom);

static ComponentResult      PrimeSource(ULawDecompGlobalsPtr globals);

static unsigned long        SamplesToBytes(unsigned long sampleCount,  CompressionInfoPtr compInfo);

static unsigned long        BytesToSamples(unsigned long byteCount,  CompressionInfoPtr compInfo);

static unsigned long        SamplesToFrames(unsigned long sampleCount,  CompressionInfoPtr compInfo);

static unsigned long        FramesToSamples(unsigned long framesCount,  CompressionInfoPtr compInfo);

static void                 InitializeCompressionInfo(ULawDecompGlobalsPtr globals);

static OSErr                DecompressorGetInfo(ULawDecompGlobalsPtr globals, OSType selector, void *infoPtr);

static OSErr                DecompressorSetInfo(ULawDecompGlobalsPtr globals, OSType selector, void *infoPtr);

static OSErr                SetCompressorInfo(ULawDecompGlobalsPtr globals, CompressionInfoPtr cp);

static void                 ExpandULaw(Byte *inbuf, short *outbuf, short *ulawTable, long framesToConvert, short numChannels, short whichChannel, short sampleSize);

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//          Component Dispatcher

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

#if TARGET_CPU_68K

    #define COMPONENT_C_DISPATCHER

    #define COMPONENT_DISPATCH_MAIN

#endif

#define CALLCOMPONENT_BASENAME()        __uLawDecomp

#define CALLCOMPONENT_GLOBALS()         ULawDecompGlobalsPtr storage

#define SOUNDCOMPONENT_BASENAME()       CALLCOMPONENT_BASENAME()

#define SOUNDCOMPONENT_GLOBALS()        CALLCOMPONENT_GLOBALS()

#define COMPONENT_UPP_SELECT_ROOT()     SoundComponent

#define COMPONENT_DISPATCH_FILE         "uLawCodecDispatch.h"

#define GET_DELEGATE_COMPONENT()        (storage->sourceComponent)

#include "Components.k.h"

#include "Sound.k.h"

#include "ComponentDispatchHelper.c"

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//          Component Routines

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

static pascal ComponentResult __uLawDecompOpen(ULawDecompGlobalsPtr globals, ComponentInstance self)

{

    OSErr                       result;

    globals = (ULawDecompGlobalsPtr)NewPtrSysClear(sizeof(ULawDecompGlobals));

    FailWithAction(globals == nil, result = MemError(), Failure);

    result = GetComponentResource((Component)self, k16BitTableResType, kSoundDecompressorResID, &globals->ulawTableHandle);

    FailIf(result != noErr, NoResource);

    HLock(globals->ulawTableHandle);

    globals->ulawTable = (short *)StripAddress(*globals->ulawTableHandle);

#if TARGET_RT_LITTLE_ENDIAN

    // The ulawTable values are stored in the resource fork as 16-bit big-endian data

    // (Rez assumes any integers in a .r file are big-endian, for compatibility).

    // Make them little-endian, so we can do math with them on this little-endian machine.

    // There are ways to get the Resource Manager to do this for you by registering

    // a callback for the resource type, but that's beyond the scope of this example.

    {

        long numElements = GetHandleSize(globals->ulawTableHandle) / 2;

        long i;

        for (i = 0; i < numElements; i++) {

            globals->ulawTable[i] = EndianU16_BtoN(globals->ulawTable[i]);

        }

    }

#endif

    globals->outputData.format = kOutputFormat;         // output format

    globals->outputData.sampleSize = kOutputSampleSize; // output sample size

    globals->outputBufferSamples = kMaxOutputSamples;   // will be set to requested->sampleCount later

    InitializeCompressionInfo(globals);

    // set our storage pointer to our globals

    SetComponentInstanceStorage(self, (Handle) globals);

#if !TARGET_OS_MAC

    globals->interruptMutex = QTMLCreateMutex();

    FailWithAction(globals->interruptMutex == nil, result = memFullErr, NoMutex);

#endif

    return (noErr);

NoMutex:

    DisposeHandle(globals->ulawTableHandle);

NoResource:

    DisposePtr((Ptr)globals);

Failure:

    return (result);

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

static pascal ComponentResult __uLawDecompClose(ULawDecompGlobalsPtr globals, ComponentInstance self)

{

    ComponentResult     result;

    self; // suppress "unused variable" warning for all compilers

    if (globals != nil)                                         // we have some globals

    {

        if (globals->sourceComponent)

        {

            result = CloseComponent(globals->sourceComponent);  // torch source component

            FailMessage(result != noErr);

        }

        globals->outputData.sampleCount = 0;                    // nothing in our buffer now

#if !TARGET_OS_MAC

        if (globals->interruptMutex != nil) 

        {

            QTMLDestroyMutex(globals->interruptMutex);

            globals->interruptMutex = nil;

        }

#endif

        if (globals->ulawTableHandle != nil)

            DisposeHandle(globals->ulawTableHandle);

        DisposePtr((Ptr)globals);                               // torch them

    }

    return (noErr);

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

pascal ComponentResult __uLawDecompVersion(ULawDecompGlobalsPtr globals)

{

    globals; // suppress "unused variable" warning for all compilers

    return (kSoundDecompressorVersion);

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

// Sound Component Methods

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

static pascal ComponentResult __uLawDecompSetSource(ULawDecompGlobalsPtr globals, SoundSource sourceID, ComponentInstance source)

{

    SoundComponentDataPtr   sourceData;

    globals->sourceID = sourceID;

    globals->sourceComponent = source;                  // our food source

    globals->sourceDataPtr = nil;                       // nothing read from source yet

    // make sure we can get the source we need

    return (SoundComponentSetOutput(source, &globals->outputData, &sourceData));

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

static pascal ComponentResult __uLawDecompSetOutput(ULawDecompGlobalsPtr globals, SoundComponentDataPtr requested, SoundComponentDataPtr *actual)

{

    globals->outputBufferSamples = requested->sampleCount;              // no. samples to output

    if (globals->outputBufferSamples > kMaxOutputSamples)               // too much for our buffer

        globals->outputBufferSamples = kMaxOutputSamples;

    // must be one of the output formats we support

    FailIf((requested->sampleSize == 8) && (requested->format != k8BitOffsetBinaryFormat), Failure);

    // decompressors output to native endian by definition

    FailIf((requested->sampleSize == 16) && (requested->format != k16BitNativeEndianFormat), Failure);

    globals->outputData = *requested;

    return (noErr);

Failure:

    // here's what we can do

    *actual = &globals->outputData;

    return (paramErr);

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

static pascal ComponentResult __uLawDecompGetInfo(ULawDecompGlobalsPtr globals, SoundSource sourceID, OSType selector, void *infoPtr)

{

    ComponentResult     result;

    result = noErr;

    switch (selector)

    {

        case siCompressionFactor:

            *(CompressionInfoPtr)infoPtr = globals->compInfo;

            break;

        case siDecompressionParams:

            result = GetDecompressionParams(globals, (AudioDecompressionAtomHandle *)infoPtr);

            break;

        default:

            if (globals->sourceComponent == nil)

                result = siUnknownInfoType;

            else

                result = SoundComponentGetInfo(globals->sourceComponent, sourceID, selector, infoPtr);

            break;

    }

    return (result);

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

static pascal ComponentResult __uLawDecompSetInfo(ULawDecompGlobalsPtr globals, SoundSource sourceID, OSType selector, void *infoPtr)

{

    ComponentResult     result;

    result = noErr;

    switch (selector)

    {

        case siDecompressionParams:

            result = SetDecompressionParams(globals, (UserDataAtom *)infoPtr);

            break;

        default:

            if (globals->sourceComponent == nil)

                result = siUnknownInfoType;

            else

                result = SoundComponentSetInfo(globals->sourceComponent, sourceID, selector, infoPtr);

    }

    return (result);

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

static pascal ComponentResult __uLawDecompPlaySourceBuffer(ULawDecompGlobalsPtr globals, SoundSource sourceID, SoundParamBlockPtr pb, long actions)

{

    globals->sourceDataPtr = nil;                       // no source yet

    globals->outputData.sampleCount = 0;                // our buffer is empty

    return (SoundComponentPlaySourceBuffer(globals->sourceComponent, sourceID, pb, actions));

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

static pascal ComponentResult __uLawDecompStopSource(ULawDecompGlobalsPtr globals, short count, SoundSource *sources)

{

    globals->sourceDataPtr = nil;                       // assume our source is gone

    return (SoundComponentStopSource(globals->sourceComponent, count, sources));

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

static pascal ComponentResult __uLawDecompGetSourceData(ULawDecompGlobalsPtr globals, SoundComponentDataPtr *resultData)

{

    SoundComponentDataPtr sourceDataPtr;

    long                samplesConverted;

    long                framesToConvert;

    ComponentResult     result = noErr;

    Byte                *inputBuffer;

    if (globals->sourceDataPtr == nil)                      // no source pointer so...

    {

        result = PrimeSource(globals);                      // get data from our source

        FailIf(result != noErr, Exit);

    }

    sourceDataPtr = globals->sourceDataPtr;                 // get pointer to source sound component

    if (sourceDataPtr->sampleCount == 0)                    // source is out of bytes

    {                                                       // get some more source

        result = SoundComponentGetSourceData(globals->sourceComponent, &globals->sourceDataPtr);

        FailIf(result != noErr, Exit);

        sourceDataPtr = globals->sourceDataPtr;             // get pointer to source sound component

    }

    if ((sourceDataPtr->format == globals->outputData.format) ||    // input and output are same

        (sourceDataPtr->buffer == nil) ||                           // or no source buffer

        (sourceDataPtr->sampleCount == 0))                          // or no source buffer

    {

        globals->sourceDataPtr = nil;                       // get new source next time

        *resultData = sourceDataPtr;                        // pass source on down

    }

    else

    {

        framesToConvert = SamplesToFrames(sourceDataPtr->sampleCount, &globals->compInfo);

        if (framesToConvert)                                // source has some data for us

        {

            if (framesToConvert > globals->maxFrames)

                framesToConvert = globals->maxFrames;       // limited to size of output

            samplesConverted = FramesToSamples(framesToConvert, &globals->compInfo);

            inputBuffer = sourceDataPtr->buffer;            // point at input buffer

            sourceDataPtr->buffer += SamplesToBytes(samplesConverted, &globals->compInfo);  // update input buffer

            sourceDataPtr->sampleCount -= samplesConverted;

            if (sourceDataPtr->numChannels == 1)

            {

                ExpandULaw(inputBuffer, (short *) globals->buffer, globals->ulawTable,

                            framesToConvert, 1, 1, globals->outputData.sampleSize);

            }

            else

            {

                // do the left samples

                ExpandULaw(inputBuffer, (short *) globals->buffer, globals->ulawTable,

                            framesToConvert, 2, 1, globals->outputData.sampleSize);

                // do the right samples

                ExpandULaw(inputBuffer, (short *) globals->buffer, globals->ulawTable,

                            framesToConvert, 2, 2, globals->outputData.sampleSize);

            }

        }

        else

            samplesConverted = 0;

        globals->outputData.buffer = globals->buffer;       // data in this buffer

        globals->outputData.sampleCount = samplesConverted; // return num. samples converted

        *resultData = &globals->outputData;                     // tell them what we made

    }

Exit:

    return (result);

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//      sub routines    _

//                    _|_

//      o       _____|   |_____

//        o o  +______________/

//

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

static OSErr GetDecompressionParams(ULawDecompGlobalsPtr globals, AudioDecompressionAtomHandle *params)

{

    AudioDecompressionAtomHandle    atom;

    AudioDecompressionAtomPtr       atomPtr;

    OSErr                           result;

    globals; // suppress "unused variable" warning for all compilers

    result = noErr;

    atom = (AudioDecompressionAtomHandle)NewHandle(sizeof(AudioDecompressionAtom));

    FailWithAction(atom == nil, result = MemError(), Exit);

    atomPtr = *atom;

    atomPtr->formatData.size = EndianU32_NtoB(sizeof(AudioFormatAtom));

    atomPtr->formatData.atomType = EndianU32_NtoB(kAudioFormatAtomType);

    atomPtr->formatData.format = EndianU32_NtoB(kInputFormat);

    atomPtr->endianData.size = EndianU32_NtoB(sizeof(AudioEndianAtom));

    atomPtr->endianData.atomType = EndianU32_NtoB(kAudioEndianAtomType);

    atomPtr->endianData.littleEndian = EndianU16_NtoB(false);       // µlaw is not little endian

    atomPtr->terminatorData.size = EndianU32_NtoB(sizeof(AudioTerminatorAtom));

    atomPtr->terminatorData.atomType = EndianU32_NtoB(kAudioTerminatorAtomType);

    *params = atom;

Exit:

    return (result);

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

static OSErr SetDecompressionParams(ULawDecompGlobalsPtr globals, UserDataAtom *atom)

{

    OSErr           result;

    short           littleEndian;

    Boolean         moreAtoms;

    globals; // suppress "unused variable" warning for all compilers

    result = noErr;

    moreAtoms = true;

    littleEndian = false;

    do

    {

        long atomSize = EndianS32_BtoN(atom->size);

        FailWithAction(atomSize < 8, result = invalidAtomErr, Exit);

        switch (EndianU32_BtoN(atom->atomType))

        {

            case kAudioFormatAtomType:

                FailWithAction(((AudioFormatAtom *)atom)->format != EndianU32_NtoB(kInputFormat), result = badFormat, Exit);

                break;

            case kAudioEndianAtomType:

#if !TARGET_OS_MAC

                // Don't do this during an interrupt

                QTMLGrabMutex(globals->interruptMutex);

#endif

                littleEndian = EndianU16_BtoN(((AudioEndianAtom *)atom)->littleEndian);

#if !TARGET_OS_MAC

                QTMLReturnMutex(globals->interruptMutex);

#endif

                break;

            case kAudioTerminatorAtomType:

                moreAtoms = false;

                break;

            default:    // unknown atom type

                break;

        }

        atom = (UserDataAtom *)((long)atom + atomSize);

    } while (moreAtoms);

    if (littleEndian)

        result = paramErr;                      // we do not do little endian

Exit:

    return (result);

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

static ComponentResult PrimeSource(ULawDecompGlobalsPtr globals)

{

    ComponentResult         result = noErr;

    SoundComponentDataPtr   sourceDataPtr;

    result = SoundComponentGetSourceData(globals->sourceComponent, &globals->sourceDataPtr);

    FailIf(result != noErr, Exit);

    FailWithAction(globals->sourceDataPtr == nil, result = paramErr, Exit);

    sourceDataPtr = globals->sourceDataPtr;

    globals->outputData.flags = sourceDataPtr->flags;               // copy flags unchanged

    globals->outputData.sampleRate = sourceDataPtr->sampleRate;     // copy sample rate unchanged

    globals->outputData.numChannels = sourceDataPtr->numChannels;   // copy numchannels unchanged

    // update bytesPerFrame according to number of channels

    globals->compInfo.bytesPerFrame = globals->compInfo.bytesPerPacket * sourceDataPtr->numChannels;

    globals->maxFrames = SamplesToFrames(globals->outputBufferSamples, &globals->compInfo);

Exit:

    return (result);

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

static unsigned long SamplesToBytes(unsigned long sampleCount, CompressionInfoPtr compInfo)

{

    return ((sampleCount / compInfo->samplesPerPacket) * compInfo->bytesPerFrame);

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

static unsigned long BytesToSamples(unsigned long byteCount, CompressionInfoPtr compInfo)

{

    return ((byteCount / compInfo->bytesPerFrame) * compInfo->samplesPerPacket);

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

static unsigned long SamplesToFrames(unsigned long sampleCount, CompressionInfoPtr compInfo)

{

    return (sampleCount / compInfo->samplesPerPacket);

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

static unsigned long FramesToSamples(unsigned long frameCount, CompressionInfoPtr compInfo)

{

    return (frameCount * compInfo->samplesPerPacket);

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

static void InitializeCompressionInfo(ULawDecompGlobalsPtr globals)

{

    globals->compInfo.recordSize = sizeof(CompressionInfo);

    globals->compInfo.format = kInputFormat;

    globals->compInfo.compressionID = fixedCompression;

    globals->compInfo.samplesPerPacket = kULawBlockSamples;

    globals->compInfo.bytesPerPacket = kULawBlockBytes;

    globals->compInfo.bytesPerSample = kULawBytesPerSample;

    globals->compInfo.bytesPerFrame = kULawBlockBytes;

    globals->compInfo.futureUse1 = 0;

}

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

//          µLaw 2:1 Decompression

//~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

#if TARGET_RT_BIG_ENDIAN

    #define GetEndianHighByte(p) (*(Byte *)(&p))

#else

    #define GetEndianHighByte(p) (*((Byte *)(&p)+1))

#endif

void ExpandULaw(Byte *inbuf, short *outbuf, short *ulawTable, 

                long framesToConvert, short numChannels, short whichChannel, short sampleSize)

{

    short       i;

    whichChannel -= 1;

    inbuf += whichChannel;

    if (sampleSize == 8)

    {

        Byte    *outbuf8 = (Byte *) outbuf;

        Byte    b, toggle = 0x80;

        if (numChannels == 1)

        {

            for (i = framesToConvert - 1; i >= 0; --i)

            {

                b = GetEndianHighByte(ulawTable[*inbuf++]);

                b ^= toggle;

                *outbuf8++ = b;

            }

        }

        else

        {

            outbuf8 += whichChannel;

            for (i = framesToConvert - 1; i >= 0; --i)

            {

                b = GetEndianHighByte(ulawTable[*inbuf]);

                b ^= toggle;

                *outbuf8 = b;

                inbuf += 2;

                outbuf8 += 2;

            }

        }

    }

    else

    {

        if (numChannels == 1)

        {

            for (i = framesToConvert - 1; i >= 0; --i)

            {

                *outbuf++ = ulawTable[*inbuf++];

            }

        }

        else

        {

            outbuf += whichChannel;

            for (i = framesToConvert - 1; i >= 0; --i)

            {

                *outbuf = ulawTable[*inbuf];

                inbuf += 2;

                outbuf += 2;

            }

        }

    }

}