/*

* Copyright (c) 2010 Ixonos Plc.

* All rights reserved.

* This component and the accompanying materials are made available

* under the terms of the "Eclipse Public License v1.0"

* which accompanies this distribution, and is available

* at the URL "http://www.eclipse.org/legal/epl-v10.html".

*

* Initial Contributors:

* Nokia Corporation - Initial contribution

*

* Contributors:

* Ixonos Plc

*

* Description:

*

*/

#include "resampler_sinc_conv_two_to_three_int16.h"

#include "resampler_clip.h"

#include "resampler_sinc_conv_two_to_three_tables_standard.h"

#include "resampler_sinc_conv_two_to_three_int16.inl"

#include <string.h>

static const int LC_ZERO_CROSSINGS = RESAMPLER_TWO_TO_THREE_ZERO_CROSSINGS_STANDARD;

static const int LC_MOD3[6] = { 0, 1, 2, 0, 1, 2 };

RESAMPLER_SincConvTwoToThreeInt16::RESAMPLER_SincConvTwoToThreeInt16(int channelCount) :

m_memBuffers(0),

m_scratchBuffer(0),

m_filter1(RESAMPLER_TWO_TO_THREE_FILTER1_STANDARD),

m_filter2(RESAMPLER_TWO_TO_THREE_FILTER2_STANDARD),

m_channelCount(channelCount),

m_blockSize(0),

m_channelEnabled(0),

m_inputSamples(0),

m_state(2)

{

}

RESAMPLER_SincConvTwoToThreeInt16::~RESAMPLER_SincConvTwoToThreeInt16()

{

    DeInit();

}

bool RESAMPLER_SincConvTwoToThreeInt16::InitInputDriven()

{

    return Init();

}

bool RESAMPLER_SincConvTwoToThreeInt16::InitOutputDriven()

{

    return Init();

}

/*

*   This function must be called before using the converter.

*   This function reserves memory for ring buffers and 

*   prepares the ring buffer indexing.

*/

bool RESAMPLER_SincConvTwoToThreeInt16::Init()

{

    int i = 0;

    m_memBuffers = new int16 *[m_channelCount];

    if (!m_memBuffers)

    {

        return false;

    }

    for (i = 0; i < m_channelCount; i++) 

    {

        m_memBuffers[i] = 0;

    }

    m_channelCount = m_channelCount;

    m_channelEnabled = new bool[m_channelCount];

    if (!m_channelEnabled)

    {

        DeInit();

        return false;

    }

    for (i = 0; i < m_channelCount; i++) 

    {

        m_channelEnabled[i] = true;

    }

    for (i = 0; i < m_channelCount; i++) 

    {

        m_memBuffers[i] = new int16[LC_ZERO_CROSSINGS * 2];

        if (!m_memBuffers[i])

        {

            DeInit();

            return false;

        }

        memset(m_memBuffers[i], 0, sizeof(int16) * (LC_ZERO_CROSSINGS * 2));

    }

    return true;

}

void RESAMPLER_SincConvTwoToThreeInt16::DeInit()

{

    if (m_channelCount)

    {

        for (int i = 0; i < m_channelCount; i++)

        {

            delete [] m_memBuffers[i];

        }

        delete [] m_memBuffers;

        delete [] m_channelEnabled;

    }

}

void RESAMPLER_SincConvTwoToThreeInt16::EnableChannel(int channel)

{

    m_channelEnabled[channel] = true;

}

void RESAMPLER_SincConvTwoToThreeInt16::DisableChannel(int channel)

{

    m_channelEnabled[channel] = false;

}

int RESAMPLER_SincConvTwoToThreeInt16::MaxOutputSampleCount(int inSamples) const 

{ 

    return 3 * inSamples / 2 + 1; 

}

int RESAMPLER_SincConvTwoToThreeInt16::ProcessFromInput(int16 *outputBuffers[], 

                                                  int16 *inputBuffers[], 

                                                  int inSamples)

{

    int outSamples( (3*inSamples + 2 - m_state) / 2 );

    m_inputSamples = inSamples;

    return ProcessToOutput(outputBuffers, inputBuffers, outSamples);

}

size_t 

RESAMPLER_SincConvTwoToThreeInt16::ScratchMemoryNeedOutputDriven(int maxOutputBlockSize) const

{

    return ScratchMemoryNeedInputDriven((2*maxOutputBlockSize + 2) / 3);

}

void 

RESAMPLER_SincConvTwoToThreeInt16::SetScratchBufferOutputDriven(char *buffer)

{

    m_scratchBuffer = (int16 *)buffer;

}

size_t 

RESAMPLER_SincConvTwoToThreeInt16::ScratchMemoryNeedInputDriven(int maxInputBlockSize) const

{

    return sizeof(int16) * (LC_ZERO_CROSSINGS * 2 + maxInputBlockSize);

}

void 

RESAMPLER_SincConvTwoToThreeInt16::SetScratchBufferInputDriven(char *buffer)

{

    m_scratchBuffer = (int16 *)buffer;

}

int RESAMPLER_SincConvTwoToThreeInt16::MaxInputSampleCount(int outSamples) const 

{ 

    return (2*outSamples+2)/3; 

}

/*

*   This function returns the value, which is given as

*   a parameter to the nextSamplesOut() function. This

*   function must be called every time before calling

*   nextSamplesOut.

*/

int RESAMPLER_SincConvTwoToThreeInt16::InSamplesNeeded(int outSamples)

{

    m_inputSamples = (2 * outSamples + m_state) / 3;

    return m_inputSamples;

}

int RESAMPLER_SincConvTwoToThreeInt16::ProcessToOutput(int16 *outputBuffers[], 

                                                 int16 *inputBuffers[], 

                                                 int outSamples)

{

    static const int FILTER_LENGTH = 2 * LC_ZERO_CROSSINGS; 

    int i, j, k;

    int bufReadHead1 = LC_ZERO_CROSSINGS + m_state;

    int bufReadHead2 = LC_ZERO_CROSSINGS + (m_state == 1 ? 1 : 0);

    int bufReadHead3 = LC_ZERO_CROSSINGS + (m_state != 1 ? 1 : 0);

    for (i = 0; i < m_channelCount; i++) 

    {

        if (!m_channelEnabled[i])

        {

            break;

        }

        int16 *tempBuf = m_scratchBuffer;

        int16 *outBuf  = outputBuffers[i];

        memcpy(m_scratchBuffer, m_memBuffers[i], FILTER_LENGTH * sizeof(int16));

        memcpy(tempBuf + FILTER_LENGTH, 

               inputBuffers[i], 

               m_inputSamples * sizeof(int16));

        // copy every second sample into every third index of output buffer.

        tempBuf = m_scratchBuffer + bufReadHead1;

        for (j = 0, k = m_state; k < outSamples; j+=2, k+=3)

        {

            outBuf[k] = tempBuf[j]; 

        }

        // Do band limited interpolation and set the result into 

        // every third index in the output buffer. 

        tempBuf = m_scratchBuffer + bufReadHead2;

        for (j = 0, k = LC_MOD3[m_state+1]; k < outSamples; j += 2, k += 3) 

        {

             // Note that the filters are reversed

            int32 newSample = RESAMPLER_SincConvTwoToThreeFilterInt16(tempBuf + j, 

                                                                m_filter2,

                                                                m_filter1,

                                                                LC_ZERO_CROSSINGS);

            // round and shift down 

            outBuf[k] = (int16)RESAMPLER_Clip16((newSample + 16384) >> 15);

        }

        // Do band limited interpolation and set the result into 

        // every third index in the output buffer. 

        tempBuf = m_scratchBuffer + bufReadHead3;

        for (j = 0, k = LC_MOD3[m_state+2]; k < outSamples; j += 2, k += 3) 

        {

            int32 newSample = RESAMPLER_SincConvTwoToThreeFilterInt16(tempBuf + j, 

                                                                m_filter1,

                                                                m_filter2,

                                                                LC_ZERO_CROSSINGS);

            // round and shift down 

            outBuf[k] = (int16)RESAMPLER_Clip16((newSample + 16384) >> 15);

        }

        // Copy the newest samples to the beginning of the buffer

        memcpy(m_memBuffers[i], 

               m_scratchBuffer + m_inputSamples, 

               FILTER_LENGTH * sizeof(int16));       

    }    

    // Update state according to amount of output samples.

    m_state = LC_MOD3[m_state + (3 - (outSamples % 3))];

    return outSamples;

}