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share/public_html/static/music_worklet_inprogress/decoder/deps/dr_libs/dr_flac.h  view on Meta::CPAN

    samplesInPartition = (blockSize / (1 << partitionOrder)) - order;
    partitionsRemaining = (1 << partitionOrder);
    for (;;)
    {
        drflac_uint8 riceParam = 0;
        if (residualMethod == DRFLAC_RESIDUAL_CODING_METHOD_PARTITIONED_RICE) {
            if (!drflac__read_uint8(bs, 4, &riceParam)) {
                return DRFLAC_FALSE;
            }
            if (riceParam == 15) {
                riceParam = 0xFF;
            }
        } else if (residualMethod == DRFLAC_RESIDUAL_CODING_METHOD_PARTITIONED_RICE2) {
            if (!drflac__read_uint8(bs, 5, &riceParam)) {
                return DRFLAC_FALSE;
            }
            if (riceParam == 31) {
                riceParam = 0xFF;
            }
        }

        if (riceParam != 0xFF) {
            if (!drflac__read_and_seek_residual__rice(bs, samplesInPartition, riceParam)) {
                return DRFLAC_FALSE;
            }
        } else {
            drflac_uint8 unencodedBitsPerSample = 0;
            if (!drflac__read_uint8(bs, 5, &unencodedBitsPerSample)) {
                return DRFLAC_FALSE;
            }

            if (!drflac__seek_bits(bs, unencodedBitsPerSample * samplesInPartition)) {
                return DRFLAC_FALSE;
            }
        }


        if (partitionsRemaining == 1) {
            break;
        }

        partitionsRemaining -= 1;
        samplesInPartition = blockSize / (1 << partitionOrder);
    }

    return DRFLAC_TRUE;
}


static drflac_bool32 drflac__decode_samples__constant(drflac_bs* bs, drflac_uint32 blockSize, drflac_uint32 subframeBitsPerSample, drflac_int32* pDecodedSamples)
{
    drflac_uint32 i;

    /* Only a single sample needs to be decoded here. */
    drflac_int32 sample;
    if (!drflac__read_int32(bs, subframeBitsPerSample, &sample)) {
        return DRFLAC_FALSE;
    }

    /*
    We don't really need to expand this, but it does simplify the process of reading samples. If this becomes a performance issue (unlikely)
    we'll want to look at a more efficient way.
    */
    for (i = 0; i < blockSize; ++i) {
        pDecodedSamples[i] = sample;
    }

    return DRFLAC_TRUE;
}

static drflac_bool32 drflac__decode_samples__verbatim(drflac_bs* bs, drflac_uint32 blockSize, drflac_uint32 subframeBitsPerSample, drflac_int32* pDecodedSamples)
{
    drflac_uint32 i;

    for (i = 0; i < blockSize; ++i) {
        drflac_int32 sample;
        if (!drflac__read_int32(bs, subframeBitsPerSample, &sample)) {
            return DRFLAC_FALSE;
        }

        pDecodedSamples[i] = sample;
    }

    return DRFLAC_TRUE;
}

static drflac_bool32 drflac__decode_samples__fixed(drflac_bs* bs, drflac_uint32 blockSize, drflac_uint32 subframeBitsPerSample, drflac_uint8 lpcOrder, drflac_int32* pDecodedSamples)
{
    drflac_uint32 i;

    static drflac_int32 lpcCoefficientsTable[5][4] = {
        {0,  0, 0,  0},
        {1,  0, 0,  0},
        {2, -1, 0,  0},
        {3, -3, 1,  0},
        {4, -6, 4, -1}
    };

    /* Warm up samples and coefficients. */
    for (i = 0; i < lpcOrder; ++i) {
        drflac_int32 sample;
        if (!drflac__read_int32(bs, subframeBitsPerSample, &sample)) {
            return DRFLAC_FALSE;
        }

        pDecodedSamples[i] = sample;
    }

    if (!drflac__decode_samples_with_residual(bs, subframeBitsPerSample, blockSize, lpcOrder, 0, 4, lpcCoefficientsTable[lpcOrder], pDecodedSamples)) {
        return DRFLAC_FALSE;
    }

    return DRFLAC_TRUE;
}

static drflac_bool32 drflac__decode_samples__lpc(drflac_bs* bs, drflac_uint32 blockSize, drflac_uint32 bitsPerSample, drflac_uint8 lpcOrder, drflac_int32* pDecodedSamples)
{
    drflac_uint8 i;
    drflac_uint8 lpcPrecision;
    drflac_int8 lpcShift;
    drflac_int32 coefficients[32];