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avfilter/af_sofalizer: speed and clean up fast convolution a little

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Signed-off-by: Paul B Mahol <onemda@gmail.com>
This commit is contained in:
Paul B Mahol 2017-01-09 18:15:03 +01:00
parent cd09e3b349
commit 7aef56864c
1 changed files with 9 additions and 5 deletions
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14
libavfilter/af_sofalizer.c
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@ -703,6 +703,8 @@ static int sofalizer_fast_convolute(AVFilterContext *ctx, void *arg, int jobnr,
FFTContext *fft = s->fft[jobnr];
const int n_conv = s->n_conv;
const int n_fft = s->n_fft;
const float fft_scale = 1.0f / s->n_fft;
FFTComplex *hrtf_offset;
int wr = *write;
int n_read;
int i, j;
@ -736,6 +738,7 @@ static int sofalizer_fast_convolute(AVFilterContext *ctx, void *arg, int jobnr,
/* outer loop: go through all input channels to be convolved */
offset = i * n_fft; /* no. samples already processed */
hrtf_offset = hrtf + offset;
/* fill FFT input with 0 (we want to zero-pad) */
memset(fft_in, 0, sizeof(FFTComplex) * n_fft);
@ -750,14 +753,15 @@ static int sofalizer_fast_convolute(AVFilterContext *ctx, void *arg, int jobnr,
av_fft_permute(fft, fft_in);
av_fft_calc(fft, fft_in);
for (j = 0; j < n_fft; j++) {
const FFTComplex *hcomplex = hrtf_offset + j;
const float re = fft_in[j].re;
const float im = fft_in[j].im;
/* complex multiplication of input signal and HRTFs */
/* output channel (real): */
fft_in[j].re = re * (hrtf + offset + j)->re - im * (hrtf + offset + j)->im;
fft_in[j].re = re * hcomplex->re - im * hcomplex->im;
/* output channel (imag): */
fft_in[j].im = re * (hrtf + offset + j)->im + im * (hrtf + offset + j)->re;
fft_in[j].im = re * hcomplex->im + im * hcomplex->re;
}
/* transform output signal of current channel back to time domain */
@ -766,14 +770,14 @@ static int sofalizer_fast_convolute(AVFilterContext *ctx, void *arg, int jobnr,
for (j = 0; j < in->nb_samples; j++) {
/* write output signal of current channel to output buffer */
dst[2 * j] += fft_in[j].re / (float)n_fft;
dst[2 * j] += fft_in[j].re * fft_scale;
}
for (j = 0; j < n_samples - 1; j++) { /* overflow length is IR length - 1 */
/* write the rest of output signal to overflow buffer */
int write_pos = (wr + j) & modulo;
*(ringbuffer + write_pos) += fft_in[in->nb_samples + j].re / (float)n_fft;
*(ringbuffer + write_pos) += fft_in[in->nb_samples + j].re * fft_scale;
}
}
@ -781,7 +785,7 @@ static int sofalizer_fast_convolute(AVFilterContext *ctx, void *arg, int jobnr,
for (i = 0; i < out->nb_samples; i++) {
/* clippings counter */
if (fabs(*dst) > 1) { /* if current output sample > 1 */
*n_clippings = *n_clippings + 1;
n_clippings[0]++;
}
/* move output buffer pointer by +2 to get to next sample of processed channel: */