/*

* 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_one_int16.h"

#include "resampler_clip.h"

#include "resampler_sinc_conv_two_to_one_tables_standard.h"

#include "resampler_sinc_conv_filter_two_to_one_int16.h"

#include <string.h>

/*

 * The amount of zero crossings in positive or negative

 * side of the sinc function. Because of filter symmetry

 * the amount of filter taps used in convolution is

 * zero crossings * 2.

 */

static const int LC_MAX_ZERO_CROSSINGS = RESAMPLER_TWO_TO_ONE_ZERO_CROSSINGS_STANDARD;

static const int LC_BUFFER_ACCESS_OUTPUT = 2 * LC_MAX_ZERO_CROSSINGS;

RESAMPLER_SincConvTwoToOneInt16::RESAMPLER_SincConvTwoToOneInt16(int channelCount) :

m_memBuffers(0),

m_scratchBuffer(0),

m_channelCount(channelCount),

m_blockSize(0),

m_channelEnabled(0),

m_state(0),

m_zeroCrossings(RESAMPLER_TWO_TO_ONE_ZERO_CROSSINGS_STANDARD),

m_filterMatrix(RESAMPLER_TWO_TO_ONE_FILTERS_STANDARD)

{

}

RESAMPLER_SincConvTwoToOneInt16::~RESAMPLER_SincConvTwoToOneInt16()

{

    DeInit();

}

bool RESAMPLER_SincConvTwoToOneInt16::InitInputDriven()

{

    return Init();

}

bool RESAMPLER_SincConvTwoToOneInt16::InitOutputDriven()

{

    return Init();

}

bool 

RESAMPLER_SincConvTwoToOneInt16::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_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_MAX_ZERO_CROSSINGS * 4];

        if (!m_memBuffers[i])

        {

            DeInit();

            return false;

        }

        memset(m_memBuffers[i], 0, sizeof(int16) * (LC_MAX_ZERO_CROSSINGS * 4));

    }

    return true;

}

void 

RESAMPLER_SincConvTwoToOneInt16::DeInit()

{

    if (m_channelCount)

    {

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

        {

            delete [] m_memBuffers[i];

        }

        delete [] m_memBuffers;

        delete [] m_channelEnabled;

    }

}

void 

RESAMPLER_SincConvTwoToOneInt16::EnableChannel(int channel)

{

    m_channelEnabled[channel] = true;

}

void 

RESAMPLER_SincConvTwoToOneInt16::DisableChannel(int channel)

{

    m_channelEnabled[channel] = false;

}

size_t 

RESAMPLER_SincConvTwoToOneInt16::ScratchMemoryNeedInputDriven(int maxInputBlockSize) const

{

    return sizeof(int16) * (LC_MAX_ZERO_CROSSINGS * 4 + maxInputBlockSize);

}

void 

RESAMPLER_SincConvTwoToOneInt16::SetScratchBufferInputDriven(char *buffer)

{

    m_scratchBuffer = (int16 *)buffer;

}

size_t 

RESAMPLER_SincConvTwoToOneInt16::ScratchMemoryNeedOutputDriven(int maxOutputBlockSize) const

{

    int blockSize = 2 * maxOutputBlockSize; 

    return ScratchMemoryNeedInputDriven(blockSize);

}

void 

RESAMPLER_SincConvTwoToOneInt16::SetScratchBufferOutputDriven(char *buffer)

{

    m_scratchBuffer = (int16 *)buffer;

}

int 

RESAMPLER_SincConvTwoToOneInt16::MaxOutputSampleCount(int inSamples) const 

{ 

    return ( inSamples + 1 ) / 2; 

}

int 

RESAMPLER_SincConvTwoToOneInt16::MaxInputSampleCount(int outSamples) const

{ 

    return 2 * outSamples; 

}

int 

RESAMPLER_SincConvTwoToOneInt16::InSamplesNeeded(int outSamples)

{

    return 2 * outSamples;

}

int 

RESAMPLER_SincConvTwoToOneInt16::ProcessToOutput(int16 *outputBuffers[], 

                                           int16 *inputBuffers[], 

                                           int outSamples)

{

    int inSamples( 2 * outSamples );

    return ProcessFromInput(outputBuffers, inputBuffers, inSamples);

}

int 

RESAMPLER_SincConvTwoToOneInt16::ProcessFromInput(int16 *outputBuffers[], 

                                            int16 *inputBuffers[], 

                                            int inSamples)

{

    static const int FILTER_LENGTH = 4 * LC_MAX_ZERO_CROSSINGS;

	int i, j;

    int state = m_state;

	int outSamples = (inSamples + state) >> 1;

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

    {

        if (!m_channelEnabled[i])

        {

            break;

        }

        int16 *tempBuf = m_scratchBuffer;

        int16 *outBuf  = outputBuffers[i];

        state = m_state;

        memcpy(m_scratchBuffer, 

               m_memBuffers[i], 

               FILTER_LENGTH * sizeof(int16));

        // Read samples into memory

        memcpy(tempBuf + FILTER_LENGTH, 

               inputBuffers[i], 

               inSamples * sizeof(int16));

        tempBuf += LC_BUFFER_ACCESS_OUTPUT - state;

        for (j = 0; j < outSamples; j++) 

        {

            int32 newSample = 

                RESAMPLER_SincConvFilterTwoToOneInt16(tempBuf,

												m_filterMatrix,

												m_zeroCrossings);

            tempBuf += 2;

            // round and shift down

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

		}

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

        memcpy(m_memBuffers[i], 

               m_scratchBuffer + inSamples, 

               FILTER_LENGTH * sizeof(int16));       

    }

    m_state = (state + inSamples) & 1;

	return outSamples;

}