Function sp_conv_compute

src/core/_SoundPipe_FFT.cpp:431–484

}

int sp_conv_compute(sp_data * sp, sp_conv * p, SPFLOAT * in, SPFLOAT * out)
{
    SPFLOAT *x, *rBuf;
    int i, n, nSamples, rBufPos;

    nSamples = p->partSize;
    rBuf = &(p->ringBuf[p->rbCnt * (nSamples << 1)]);
    /* store input signal in buffer */
    rBuf[p->cnt] = *in;
    /* copy output signals from buffer */
    *out = p->outBuffers[0][p->cnt];

    /* is input buffer full ? */
    if (++p->cnt < nSamples)
    {
        return SP_OK;
    }
    /* reset buffer position */
    p->cnt = 0;
    /* calculate FFT of input */
    for (i = nSamples; i < (nSamples << 1); i++)
    {
        /* Zero padding */
        rBuf[i] = 0.0;
    }
    sp_fftr(&p->fft, rBuf, (nSamples << 1));
    /* update ring buffer position */
    p->rbCnt++;

    if (p->rbCnt >= p->nPartitions)
    {
        p->rbCnt = 0;
    }

    rBufPos = p->rbCnt * (nSamples << 1);
    rBuf = &(p->ringBuf[rBufPos]);
    /* PB: will only loop once since nChannels == 1*/
    for (n = 0; n < p->nChannels; n++)
    {
        /* multiply complex arrays */
        multiply_fft_buffers(p->tmpBuf, p->ringBuf, p->IR_Data[n],
                             nSamples, p->nPartitions, rBufPos);
        /* inverse FFT */
        sp_ifftr(&p->fft, p->tmpBuf, (nSamples << 1));
        /* copy to output buffer, overlap with "tail" of previous block */
        x = &(p->outBuffers[n][0]);
        for (i = 0; i < nSamples; i++)
        {
            x[i] = p->tmpBuf[i] + x[i + nSamples];
            x[i + nSamples] = p->tmpBuf[i + nSamples];
        }
    }
    return SP_OK;
}

/*
    FFT library