/*

* 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_one_to_two_int16.h"

#include "resampler_clip.h"

#include "resampler_sinc_conv_one_to_two_tables_standard.h"

#include <string.h>

#include "resampler_sinc_conv_one_to_two_int16.inl"

static const int LC_ZERO_CROSSINGS = RESAMPLER_ONE_TO_TWO_ZERO_CROSSINGS_STANDARD; /* Needs to be divisible by two */

RESAMPLER_SincConvOneToTwoInt16::RESAMPLER_SincConvOneToTwoInt16(int channelCount) :

m_memBuffers(0),

m_scratchBuffer(0),

m_filter(RESAMPLER_ONE_TO_TWO_FILTERS_STANDARD),

m_channelCount(channelCount),

m_blockSize(0),

m_channelEnabled(0),

m_state(0)

{

}

RESAMPLER_SincConvOneToTwoInt16::~RESAMPLER_SincConvOneToTwoInt16()

{

    DeInit();

}

bool RESAMPLER_SincConvOneToTwoInt16::InitInputDriven()

{

    return Init();

}

bool RESAMPLER_SincConvOneToTwoInt16::InitOutputDriven()

{

    return Init();

}

bool RESAMPLER_SincConvOneToTwoInt16::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_SincConvOneToTwoInt16::DeInit()

{

    if (m_channelCount)

    {

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

        {

            delete [] m_memBuffers[i];

        }

        delete [] m_memBuffers;

        delete [] m_channelEnabled;

    }

}

void RESAMPLER_SincConvOneToTwoInt16::EnableChannel(int channel)

{

    m_channelEnabled[channel] = true;

}

void RESAMPLER_SincConvOneToTwoInt16::DisableChannel(int channel)

{

    m_channelEnabled[channel] = false;

}

size_t 

RESAMPLER_SincConvOneToTwoInt16::ScratchMemoryNeedInputDriven(int maxInputBlockSize) const

{

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

}

void 

RESAMPLER_SincConvOneToTwoInt16::SetScratchBufferInputDriven(char *buffer)

{

    m_scratchBuffer = (int16 *)buffer;

}

int RESAMPLER_SincConvOneToTwoInt16::MaxOutputSampleCount(int inSamples) const 

{ 

    return 2 * inSamples; 

}

int RESAMPLER_SincConvOneToTwoInt16::ProcessFromInput(int16 *outputBuffers[], 

                                                int16 *inputBuffers[], 

                                                int inSamples)

{

    int outSamples(2 * inSamples + m_state);

    return ProcessToOutput(outputBuffers, inputBuffers, outSamples);

}

size_t 

RESAMPLER_SincConvOneToTwoInt16::ScratchMemoryNeedOutputDriven(int maxOutputBlockSize) const

{

    return ScratchMemoryNeedInputDriven((maxOutputBlockSize + 1) >> 1);

}

void 

RESAMPLER_SincConvOneToTwoInt16::SetScratchBufferOutputDriven(char *buffer)

{

    m_scratchBuffer = (int16 *)buffer;

}

int RESAMPLER_SincConvOneToTwoInt16::MaxInputSampleCount(int outSamples) const 

{ 

    return (outSamples + 1) >> 1; 

}

int RESAMPLER_SincConvOneToTwoInt16::InSamplesNeeded(int outSamples)

{

    int inSamples( (outSamples >> 1) + (outSamples & 1) * (1 - m_state) );

    return inSamples;       

}

int RESAMPLER_SincConvOneToTwoInt16::ProcessToOutput(int16 *outputBuffers[], 

                                               int16 *inputBuffers[], 

                                               int outSamples)

{

    static const int FILTER_LENGTH = 2 * LC_ZERO_CROSSINGS;

    int i, j, k;

    int oldState = m_state;

    int newState = (oldState + outSamples) & 1;

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

    {

        if (!m_channelEnabled[i])

        {

            break;

        }

        int16 *tempBuf     = m_scratchBuffer;

        const int16 *inBuf = inputBuffers[i];

        int16 *outBuf      = outputBuffers[i];

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

        // Read samples into the memory buffer and 

        // copy samples into every second index of output buffer.

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

        {

            int16 inputSample(inBuf[j]);

            tempBuf[j + FILTER_LENGTH - 1 + oldState] = inputSample;

            outBuf[k] = tempBuf[j + LC_ZERO_CROSSINGS - 1 + oldState];

        }

        int inSamples = j;

        // Do band-limited interpolation and set the result into 

        // every second index in the output buffer. 

#ifdef RESAMPLER_SINC_CONV_ONE_TO_TWO_DUAL_FILTERING

        for (j = 0, k = 1 - oldState; k < outSamples; j+=2, k+=4) 

        {

            int newSample1(0);

            int newSample2(0);

            RESAMPLER_SincConvOneToTwoFilterDualInt16(newSample1,

                                                newSample2,

                                                tempBuf + LC_ZERO_CROSSINGS + j,

                                                m_filter,

                                                LC_ZERO_CROSSINGS);

            // Round, shift down, and clip to 16 bits

            outBuf[k] = (int16)RESAMPLER_Clip16((newSample1 + 16384) >> 15);

            if (k + 2 < outSamples)

            {

                outBuf[k+2] = (int16)RESAMPLER_Clip16((newSample2 + 16384) >> 15);

            }

        }

#else

        for (j = 0, k = 1 - oldState; k < outSamples; j++, k+=2) 

        {

            int32 newSample = 

                RESAMPLER_SincConvOneToTwoFilterInt16(tempBuf + LC_ZERO_CROSSINGS + j,

                                                m_filter,

                                                LC_ZERO_CROSSINGS);

            // Round, shift down, and clip to 16 bits

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

        }

#endif

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

        memcpy(m_memBuffers[i], 

               tempBuf + inSamples + oldState - newState, 

               (FILTER_LENGTH - 1 + newState) * sizeof(int16));

    }

    // Update state according to even or odd amount of output samples.

    m_state = newState;

    return outSamples;

}