#include "amuse/DSPCodec.h"

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;
}