amuse/lib/DSPCodec.cpp

#include "amuse/DSPCodec.hpp"

#undef min
#undef max

#pragma mark Decoder

static const int32_t NibbleToInt[16] = {0,1,2,3,4,5,6,7,-8,-7,-6,-5,-4,-3,-2,-1};

unsigned DSPDecompressFrame(int16_t* out, const uint8_t* in,
                            const int16_t coefs[8][2], int16_t* prev1, int16_t* prev2,
                            unsigned lastSample)
{
    uint8_t cIdx = (in[0]>>4) & 0xf;
    int32_t factor1 = coefs[cIdx][0];
    int32_t factor2 = coefs[cIdx][1];
    uint8_t exp = in[0] & 0xf;
    unsigned ret = 0;
    for (unsigned s=0 ; s<14 && s<lastSample ; ++s)
    {
        int32_t sampleData = (s&1)?
        NibbleToInt[(in[s/2+1])&0xf]:
        NibbleToInt[(in[s/2+1]>>4)&0xf];
        sampleData <<= exp;
        sampleData <<= 11;
        sampleData += 1024;
        sampleData +=
        factor1 * ((int32_t)(*prev1)) +
        factor2 * ((int32_t)(*prev2));
        sampleData >>= 11;
        sampleData = DSPSampClamp(sampleData);
        out[s] = sampleData;
        *prev2 = *prev1;
        *prev1 = sampleData;
        ++ret;
    }
    return ret;
}

unsigned DSPDecompressFrameStereoStride(int16_t* out, const uint8_t* in,
                                        const int16_t coefs[8][2], int16_t* prev1, int16_t* prev2,
                                        unsigned lastSample)
{
    uint32_t cIdx = (in[0]>>4) & 0xf;
    int32_t factor1 = coefs[cIdx][0];
    int32_t factor2 = coefs[cIdx][1];
    uint32_t exp = in[0] & 0xf;
    unsigned ret = 0;
    for (unsigned s=0 ; s<14 && s<lastSample ; ++s)
    {
        int32_t sampleData = (s&1)?
        NibbleToInt[(in[s/2+1])&0xf]:
        NibbleToInt[(in[s/2+1]>>4)&0xf];
        sampleData <<= exp;
        sampleData <<= 11;
        sampleData += 1024;
        sampleData +=
        factor1 * ((int32_t)(*prev1)) +
        factor2 * ((int32_t)(*prev2));
        sampleData >>= 11;
        sampleData = DSPSampClamp(sampleData);
        out[s*2] = sampleData;
        *prev2 = *prev1;
        *prev1 = sampleData;
        ++ret;
    }
    return ret;
}

unsigned DSPDecompressFrameStereoDupe(int16_t* out, const uint8_t* in,
                                      const int16_t coefs[8][2], int16_t* prev1, int16_t* prev2,
                                      unsigned lastSample)
{
    uint8_t cIdx = (in[0]>>4) & 0xf;
    int32_t factor1 = coefs[cIdx][0];
    int32_t factor2 = coefs[cIdx][1];
    uint8_t exp = in[0] & 0xf;
    unsigned ret = 0;
    for (unsigned s=0 ; s<14 && s<lastSample ; ++s)
    {
        int32_t sampleData = (s&1)?
        NibbleToInt[(in[s/2+1])&0xf]:
        NibbleToInt[(in[s/2+1]>>4)&0xf];
        sampleData <<= exp;
        sampleData <<= 11;
        sampleData += 1024;
        sampleData +=
        factor1 * ((int32_t)(*prev1)) +
        factor2 * ((int32_t)(*prev2));
        sampleData >>= 11;
        sampleData = DSPSampClamp(sampleData);
        out[s*2] = sampleData;
        out[s*2+1] = sampleData;
        *prev2 = *prev1;
        *prev1 = sampleData;
        ++ret;
    }
    return ret;
}

unsigned DSPDecompressFrameRanged(int16_t* out, const uint8_t* in,
                                  const int16_t coefs[8][2], int16_t* prev1, int16_t* prev2,
                                  unsigned firstSample, unsigned lastSample)
{
    uint8_t cIdx = (in[0]>>4) & 0xf;
    int32_t factor1 = coefs[cIdx][0];
    int32_t factor2 = coefs[cIdx][1];
    uint8_t exp = in[0] & 0xf;
    unsigned ret = 0;
    for (unsigned s=firstSample ; s<14 && s<lastSample ; ++s)
    {
        int32_t sampleData = (s&1)?
        NibbleToInt[(in[s/2+1])&0xf]:
        NibbleToInt[(in[s/2+1]>>4)&0xf];
        sampleData <<= exp;
        sampleData <<= 11;
        sampleData += 1024;
        sampleData +=
        factor1 * ((int32_t)(*prev1)) +
        factor2 * ((int32_t)(*prev2));
        sampleData >>= 11;
        sampleData = DSPSampClamp(sampleData);
        *out++ = sampleData;
        *prev2 = *prev1;
        *prev1 = sampleData;
        ++ret;
    }
    return ret;
}

unsigned DSPDecompressFrameStateOnly(const uint8_t* in,
                                     const int16_t coefs[8][2], int16_t* prev1, int16_t* prev2,
                                     unsigned lastSample)
{
    uint8_t cIdx = (in[0]>>4) & 0xf;
    int32_t factor1 = coefs[cIdx][0];
    int32_t factor2 = coefs[cIdx][1];
    uint8_t exp = in[0] & 0xf;
    unsigned ret = 0;
    for (unsigned s=0 ; s<14 && s<lastSample ; ++s)
    {
        int32_t sampleData = (s&1)?
        NibbleToInt[(in[s/2+1])&0xf]:
        NibbleToInt[(in[s/2+1]>>4)&0xf];
        sampleData <<= exp;
        sampleData <<= 11;
        sampleData += 1024;
        sampleData +=
        factor1 * ((int32_t)(*prev1)) +
        factor2 * ((int32_t)(*prev2));
        sampleData >>= 11;
        sampleData = DSPSampClamp(sampleData);
        *prev2 = *prev1;
        *prev1 = sampleData;
        ++ret;
    }
    return ret;
}

unsigned DSPDecompressFrameRangedStateOnly(const uint8_t* in,
                                           const int16_t coefs[8][2], int16_t* prev1, int16_t* prev2,
                                           unsigned firstSample, unsigned lastSample)
{
    uint8_t cIdx = (in[0]>>4) & 0xf;
    int32_t factor1 = coefs[cIdx][0];
    int32_t factor2 = coefs[cIdx][1];
    uint8_t exp = in[0] & 0xf;
    unsigned ret = 0;
    for (unsigned s=firstSample ; s<14 && s<lastSample ; ++s)
    {
        int32_t sampleData = (s&1)?
                             NibbleToInt[(in[s/2+1])&0xf]:
                             NibbleToInt[(in[s/2+1]>>4)&0xf];
        sampleData <<= exp;
        sampleData <<= 11;
        sampleData += 1024;
        sampleData +=
        factor1 * ((int32_t)(*prev1)) +
        factor2 * ((int32_t)(*prev2));
        sampleData >>= 11;
        sampleData = DSPSampClamp(sampleData);
        *prev2 = *prev1;
        *prev1 = sampleData;
        ++ret;
    }
    return ret;
}

#pragma mark Encoder

/* Reference:
 * https://code.google.com/p/brawltools/source/browse/trunk/BrawlLib/Wii/Audio/AudioConverter.cs
 */

/* Temporal Vector
 * A contiguous history of 3 samples starting with
 * 'current' and going 2 backwards
 */
typedef double tvec[3];

static inline void InnerProductMerge(tvec vecOut, short pcmBuf[14])
{
    for (int i=0 ; i<=2 ; i++)
    {
        vecOut[i] = 0.0f;
        for (int x=0 ; x<14 ; x++)
            vecOut[i] -= pcmBuf[x-i] * pcmBuf[x];
    }
}

static inline void OuterProductMerge(tvec mtxOut[3], short pcmBuf[14])
{
    for (int x=1 ; x<=2 ; x++)
        for (int y=1 ; y<=2 ; y++)
        {
            mtxOut[x][y] = 0.0;
            for (int z=0 ; z<14 ; z++)
                mtxOut[x][y] += pcmBuf[z-x] * pcmBuf[z-y];
        }
}

static bool AnalyzeRanges(tvec mtx[3], int* vecIdxsOut)
{
    double recips[3];
    double val, tmp, min, max;

    /* Get greatest distance from zero */
    for (int x=1 ; x<=2 ; x++)
    {
        val = std::max(fabs(mtx[x][1]), fabs(mtx[x][2]));
        if (val < DBL_EPSILON)
            return true;

        recips[x] = 1.0 / val;
    }

    int maxIndex = 0;
    for (int i=1 ; i<=2 ; i++)
    {
        for (int x=1 ; x<i ; x++)
        {
            tmp = mtx[x][i];
            for (int y=1 ; y<x ; y++)
                tmp -= mtx[x][y] * mtx[y][i];
            mtx[x][i] = tmp;
        }

        val = 0.0;
        for (int x=i ; x<=2 ; x++)
        {
            tmp = mtx[x][i];
            for (int y=1 ; y<i ; y++)
                tmp -= mtx[x][y] * mtx[y][i];

            mtx[x][i] = tmp;
            tmp = fabs(tmp) * recips[x];
            if (tmp >= val)
            {
                val = tmp;
                maxIndex = x;
            }
        }

        if (maxIndex != i)
        {
            for (int y=1 ; y<=2 ; y++)
            {
                tmp = mtx[maxIndex][y];
                mtx[maxIndex][y] = mtx[i][y];
                mtx[i][y] = tmp;
            }
            recips[maxIndex] = recips[i];
        }

        vecIdxsOut[i] = maxIndex;

        if (mtx[i][i] == 0.0)
            return true;

        if (i != 2)
        {
            tmp = 1.0 / mtx[i][i];
            for (int x=i+1 ; x<=2 ; x++)
                mtx[x][i] *= tmp;
        }
    }

    /* Get range */
    min = 1.0e10;
    max = 0.0;
    for (int i=1 ; i<=2 ; i++)
    {
        tmp = fabs(mtx[i][i]);
        if (tmp < min)
            min = tmp;
        if (tmp > max)
            max = tmp;
    }

    if (min / max < 1.0e-10)
        return true;

    return false;
}

static void BidirectionalFilter(tvec mtx[3], int* vecIdxs, tvec vecOut)
{
    double tmp;

    for (int i=1, x=0 ; i<=2 ; i++)
    {
        int index = vecIdxs[i];
        tmp = vecOut[index];
        vecOut[index] = vecOut[i];
        if (x != 0)
            for (int y=x ; y<=i-1 ; y++)
                tmp -= vecOut[y] * mtx[i][y];
        else if (tmp != 0.0)
            x = i;
        vecOut[i] = tmp;
    }

    for (int i=2 ; i>0 ; i--)
    {
        tmp = vecOut[i];
        for (int y=i+1 ; y<=2 ; y++)
            tmp -= vecOut[y] * mtx[i][y];
        vecOut[i] = tmp / mtx[i][i];
    }

    vecOut[0] = 1.0;
}

static bool QuadraticMerge(tvec inOutVec)
{
    double v0, v1, v2 = inOutVec[2];
    double tmp = 1.0 - (v2 * v2);

    if (tmp == 0.0)
        return true;

    v0 = (inOutVec[0] - (v2 * v2)) / tmp;
    v1 = (inOutVec[1] - (inOutVec[1] * v2)) / tmp;

    inOutVec[0] = v0;
    inOutVec[1] = v1;

    return fabs(v1) > 1.0;
}

static void FinishRecord(tvec in, tvec out)
{
    for (int z=1 ; z<=2 ; z++)
    {
        if (in[z] >= 1.0)
            in[z] = 0.9999999999;
        else if (in[z] <= -1.0)
            in[z] = -0.9999999999;
    }
    out[0] = 1.0;
    out[1] = (in[2] * in[1]) + in[1];
    out[2] = in[2];
}

static void MatrixFilter(tvec src, tvec dst)
{
    tvec mtx[3];

    mtx[2][0] = 1.0;
    for (int i=1 ; i<=2 ; i++)
        mtx[2][i] = -src[i];

    for (int i=2 ; i>0 ; i--)
    {
        double val = 1.0 - (mtx[i][i] * mtx[i][i]);
        for (int y = 1; y <= i; y++)
            mtx[i-1][y] = ((mtx[i][i] * mtx[i][y]) + mtx[i][y]) / val;
    }

    dst[0] = 1.0;
    for (int i=1 ; i<=2 ; i++)
    {
        dst[i] = 0.0;
        for (int y=1 ; y<=i ; y++)
            dst[i] += mtx[i][y] * dst[i-y];
    }
}

static void MergeFinishRecord(tvec src, tvec dst)
{
    tvec tmp;
    double val = src[0];

    dst[0] = 1.0;
    for (int i=1 ; i<=2 ; i++)
    {
        double v2 = 0.0;
        for (int y=1 ; y<i ; y++)
            v2 += dst[y] * src[i-y];

        if (val > 0.0)
            dst[i] = -(v2 + src[i]) / val;
        else
            dst[i] = 0.0;

        tmp[i] = dst[i];

        for (int y=1 ; y<i ; y++)
            dst[y] += dst[i] * dst[i - y];

        val *= 1.0 - (dst[i] * dst[i]);
    }

    FinishRecord(tmp, dst);
}

static double ContrastVectors(tvec source1, tvec source2)
{
    double val = (-source2[2] * -source2[1] + -source2[1]) / (1.0 - source2[2] * source2[2]);
    double val1 = (source1[0] * source1[0]) + (source1[1] * source1[1]) + (source1[2] * source1[2]);
    double val2 = (source1[0] * source1[1]) + (source1[1] * source1[2]);
    double val3 = source1[0] * source1[2];
    return val1 + (2.0 * val * val2) + (2.0 * (-source2[1] * val + -source2[2]) * val3);
}

static void FilterRecords(tvec vecBest[8], int exp, tvec records[], int recordCount)
{
    tvec bufferList[8];

    int buffer1[8];
    tvec buffer2;

    int index;
    double value, tempVal = 0;

    for (int x=0 ; x<2 ; x++)
    {
        for (int y=0 ; y<exp ; y++)
        {
            buffer1[y] = 0;
            for (int i=0 ; i<=2 ; i++)
                bufferList[y][i] = 0.0;
        }
        for (int z=0 ; z<recordCount ; z++)
        {
            index = 0;
            value= 1.0e30;
            for (int i=0 ; i<exp ; i++)
            {
                tempVal = ContrastVectors(vecBest[i], records[z]);
                if (tempVal < value)
                {
                    value = tempVal;
                    index = i;
                }
            }
            buffer1[index]++;
            MatrixFilter(records[z], buffer2);
            for (int i=0 ; i<=2 ; i++)
                bufferList[index][i] += buffer2[i];
        }

        for (int i=0 ; i<exp ; i++)
            if (buffer1[i] > 0)
                for (int y=0 ; y<=2 ; y++)
                    bufferList[i][y] /= buffer1[i];

        for (int i=0 ; i<exp ; i++)
            MergeFinishRecord(bufferList[i], vecBest[i]);
    }
}

void DSPCorrelateCoefs(const short* source, int samples, short coefsOut[8][2])
{
    int numFrames = (samples + 13) / 14;
    int frameSamples;

    short* blockBuffer = (short*)calloc(sizeof(short), 0x3800);
    short pcmHistBuffer[2][14] = {};

    tvec vec1;
    tvec vec2;

    tvec mtx[3];
    int vecIdxs[3];

    tvec* records = (tvec*)calloc(sizeof(tvec), numFrames * 2);
    int recordCount = 0;

    tvec vecBest[8];

    /* Iterate though 1024-block frames */
    for (int x=samples ; x>0 ;)
    {
        if (x > 0x3800) /* Full 1024-block frame */
        {
            frameSamples = 0x3800;
            x -= 0x3800;
        }
        else /* Partial frame */
        {
            /* Zero lingering block samples */
            frameSamples = x;
            for (int z=0 ; z<14 && z+frameSamples<0x3800 ; z++)
                blockBuffer[frameSamples+z] = 0;
            x = 0;
        }

        /* Copy (potentially non-frame-aligned PCM samples into aligned buffer) */
        memcpy(blockBuffer, source, frameSamples * sizeof(short));
        source += frameSamples;


        for (int i=0 ; i<frameSamples ;)
        {
            for (int z=0 ; z<14 ; z++)
                pcmHistBuffer[0][z] = pcmHistBuffer[1][z];
            for (int z=0 ; z<14 ; z++)
                pcmHistBuffer[1][z] = blockBuffer[i++];

            InnerProductMerge(vec1, pcmHistBuffer[1]);
            if (fabs(vec1[0]) > 10.0)
            {
                OuterProductMerge(mtx, pcmHistBuffer[1]);
                if (!AnalyzeRanges(mtx, vecIdxs))
                {
                    BidirectionalFilter(mtx, vecIdxs, vec1);
                    if (!QuadraticMerge(vec1))
                    {
                        FinishRecord(vec1, records[recordCount]);
                        recordCount++;
                    }
                }
            }
        }
    }

    vec1[0] = 1.0;
    vec1[1] = 0.0;
    vec1[2] = 0.0;

    for (int z=0 ; z<recordCount ; z++)
    {
        MatrixFilter(records[z], vecBest[0]);
        for (int y=1 ; y<=2 ; y++)
            vec1[y] += vecBest[0][y];
    }
    for (int y=1 ; y<=2 ; y++)
        vec1[y] /= recordCount;

    MergeFinishRecord(vec1, vecBest[0]);


    int exp = 1;
    for (int w=0 ; w<3 ;)
    {
        vec2[0] = 0.0;
        vec2[1] = -1.0;
        vec2[2] = 0.0;
        for (int i=0 ; i<exp ; i++)
            for (int y=0 ; y<=2 ; y++)
                vecBest[exp+i][y] = (0.01 * vec2[y]) + vecBest[i][y];
        ++w;
        exp = 1 << w;
        FilterRecords(vecBest, exp, records, recordCount);
    }

    /* Write output */
    for (int z=0 ; z<8 ; z++)
    {
        double d;
        d = -vecBest[z][1] * 2048.0;
        if (d > 0.0)
            coefsOut[z][0] = (d > 32767.0) ? (short)32767 : (short)lround(d);
        else
            coefsOut[z][0] = (d < -32768.0) ? (short)-32768 : (short)lround(d);

        d = -vecBest[z][2] * 2048.0;
        if (d > 0.0)
            coefsOut[z][1] = (d > 32767.0) ? (short)32767 : (short)lround(d);
        else
            coefsOut[z][1] = (d < -32768.0) ? (short)-32768 : (short)lround(d);
    }

    /* Free memory */
    free(records);
    free(blockBuffer);

}

/* Make sure source includes the yn values (16 samples total) */
void DSPEncodeFrame(short pcmInOut[16], int sampleCount, unsigned char adpcmOut[8], const short coefsIn[8][2])
{
    int inSamples[8][16];
    int outSamples[8][14];

    int bestIndex = 0;

    int scale[8];
    double distAccum[8];

    /* Iterate through each coef set, finding the set with the smallest error */
    for (int i=0 ; i<8 ; i++)
    {
        int v1, v2, v3;
        int distance, index;

        /* Set yn values */
        inSamples[i][0] = pcmInOut[0];
        inSamples[i][1] = pcmInOut[1];

        /* Round and clamp samples for this coef set */
        distance = 0;
        for (int s=0 ; s<sampleCount ; s++)
        {
            /* Multiply previous samples by coefs */
            inSamples[i][s + 2] = v1 = ((pcmInOut[s] * coefsIn[i][1]) + (pcmInOut[s + 1] * coefsIn[i][0])) / 2048;
            /* Subtract from current sample */
            v2 = pcmInOut[s + 2] - v1;
            /* Clamp */
            v3 = (v2 >= 32767) ? 32767 : (v2 <= -32768) ? -32768 : v2;
            /* Compare distance */
            if (abs(v3) > abs(distance))
                distance = v3;
        }

        /* Set initial scale */
        for (scale[i]=0; (scale[i]<=12) && ((distance>7) || (distance<-8)); scale[i]++, distance/=2) {}
        scale[i] = (scale[i] <= 1) ? -1 : scale[i] - 2;

        do
        {
            scale[i]++;
            distAccum[i] = 0;
            index = 0;

            for (int s=0 ; s<sampleCount ; s++)
            {
                /* Multiply previous */
                v1 = ((inSamples[i][s] * coefsIn[i][1]) + (inSamples[i][s + 1] * coefsIn[i][0]));
                /* Evaluate from real sample */
                v2 = ((pcmInOut[s + 2] << 11) - v1) / 2048;
                /* Round to nearest sample */
                v3 = (v2 > 0) ? (int)((double)v2 / (1 << scale[i]) + 0.4999999f) : (int)((double)v2 / (1 << scale[i]) - 0.4999999f);

                /* Clamp sample and set index */
                if (v3 < -8)
                {
                    if (index < (v3 = -8 - v3))
                        index = v3;
                    v3 = -8;
                }
                else if (v3 > 7)
                {
                    if (index < (v3 -= 7))
                        index = v3;
                    v3 = 7;
                }

                /* Store result */
                outSamples[i][s] = v3;

                /* Round and expand */
                v1 = (v1 + ((v3 * (1 << scale[i])) << 11) + 1024) >> 11;
                /* Clamp and store */
                inSamples[i][s + 2] = v2 = (v1 >= 32767) ? 32767 : (v1 <= -32768) ? -32768 : v1;
                /* Accumulate distance */
                v3 = pcmInOut[s + 2] - v2;
                distAccum[i] += v3 * (double)v3;
            }

            for (int x=index+8 ; x>256 ; x>>=1)
                if (++scale[i] >= 12)
                    scale[i] = 11;

        } while ((scale[i] < 12) && (index > 1));
    }

    double min = DBL_MAX;
    for (int i = 0; i < 8; i++)
    {
        if (distAccum[i] < min)
        {
            min = distAccum[i];
            bestIndex = i;
        }
    }

    /* Write converted samples */
    for (int s=0 ; s<sampleCount ; s++)
        pcmInOut[s + 2] = inSamples[bestIndex][s + 2];

    /* Write ps */
    adpcmOut[0] = (char)((bestIndex << 4) | (scale[bestIndex] & 0xF));

    /* Zero remaining samples */
    for (int s=sampleCount ; s<14 ; s++)
        outSamples[bestIndex][s] = 0;

    /* Write output samples */
    for (int y=0; y<7; y++)
    {
        adpcmOut[y + 1] = (char)((outSamples[bestIndex][y * 2] << 4) | (outSamples[bestIndex][y * 2 + 1] & 0xF));
    }
}