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avfilter/af_firequalizer: add min_phase option 

Signed-off-by: Muhammad Faiz <mfcc64@gmail.com>
This commit is contained in:
Muhammad Faiz 2017-08-23 01:35:35 +07:00
parent e51073fe00
commit ae1ce0db91
2 changed files with 147 additions and 3 deletions
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3
doc/filters.texi
View File

@ -2667,6 +2667,9 @@ Default is linlog.
@item fft2
Enable 2-channel convolution using complex FFT. This improves speed significantly.
Default is disabled.
@item min_phase
Enable minimum phase impulse response. Default is disabled.
@end table
@subsection Examples

147
libavfilter/af_firequalizer.c
View File

@ -70,13 +70,17 @@ typedef struct FIREqualizerContext {
RDFTContext *rdft;
RDFTContext *irdft;
FFTContext *fft_ctx;
RDFTContext *cepstrum_rdft;
RDFTContext *cepstrum_irdft;
int analysis_rdft_len;
int rdft_len;
int cepstrum_len;
float *analysis_buf;
float *dump_buf;
float *kernel_tmp_buf;
float *kernel_buf;
float *cepstrum_buf;
float *conv_buf;
OverlapIndex *conv_idx;
int fir_len;
@ -99,6 +103,7 @@ typedef struct FIREqualizerContext {
char *dumpfile;
int dumpscale;
int fft2;
int min_phase;
int nb_gain_entry;
int gain_entry_err;
@ -135,6 +140,7 @@ static const AVOption firequalizer_options[] = {
{ "dumpfile", "set dump file", OFFSET(dumpfile), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, FLAGS },
{ "dumpscale", "set dump scale", OFFSET(dumpscale), AV_OPT_TYPE_INT, { .i64 = SCALE_LINLOG }, 0, NB_SCALE-1, FLAGS, "scale" },
{ "fft2", "set 2-channels fft", OFFSET(fft2), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS },
{ "min_phase", "set minimum phase mode", OFFSET(min_phase), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS },
{ NULL }
};
@ -147,13 +153,18 @@ static void common_uninit(FIREqualizerContext *s)
av_rdft_end(s->rdft);
av_rdft_end(s->irdft);
av_fft_end(s->fft_ctx);
av_rdft_end(s->cepstrum_rdft);
av_rdft_end(s->cepstrum_irdft);
s->analysis_rdft = s->analysis_irdft = s->rdft = s->irdft = NULL;
s->fft_ctx = NULL;
s->cepstrum_rdft = NULL;
s->cepstrum_irdft = NULL;
av_freep(&s->analysis_buf);
av_freep(&s->dump_buf);
av_freep(&s->kernel_tmp_buf);
av_freep(&s->kernel_buf);
av_freep(&s->cepstrum_buf);
av_freep(&s->conv_buf);
av_freep(&s->conv_idx);
}
@ -235,6 +246,46 @@ static void fast_convolute(FIREqualizerContext *av_restrict s, const float *av_r
}
}
static void fast_convolute_nonlinear(FIREqualizerContext *av_restrict s, const float *av_restrict kernel_buf,
float *av_restrict conv_buf, OverlapIndex *av_restrict idx,
float *av_restrict data, int nsamples)
{
if (nsamples <= s->nsamples_max) {
float *buf = conv_buf + idx->buf_idx * s->rdft_len;
float *obuf = conv_buf + !idx->buf_idx * s->rdft_len + idx->overlap_idx;
int k;
memcpy(buf, data, nsamples * sizeof(*data));
memset(buf + nsamples, 0, (s->rdft_len - nsamples) * sizeof(*data));
av_rdft_calc(s->rdft, buf);
buf[0] *= kernel_buf[0];
buf[1] *= kernel_buf[1];
for (k = 2; k < s->rdft_len; k += 2) {
float re, im;
re = buf[k] * kernel_buf[k] - buf[k+1] * kernel_buf[k+1];
im = buf[k] * kernel_buf[k+1] + buf[k+1] * kernel_buf[k];
buf[k] = re;
buf[k+1] = im;
}
av_rdft_calc(s->irdft, buf);
for (k = 0; k < s->rdft_len - idx->overlap_idx; k++)
buf[k] += obuf[k];
memcpy(data, buf, nsamples * sizeof(*data));
idx->buf_idx = !idx->buf_idx;
idx->overlap_idx = nsamples;
} else {
while (nsamples > s->nsamples_max * 2) {
fast_convolute_nonlinear(s, kernel_buf, conv_buf, idx, data, s->nsamples_max);
data += s->nsamples_max;
nsamples -= s->nsamples_max;
}
fast_convolute_nonlinear(s, kernel_buf, conv_buf, idx, data, nsamples/2);
fast_convolute_nonlinear(s, kernel_buf, conv_buf, idx, data + nsamples/2, nsamples - nsamples/2);
}
}
static void fast_convolute2(FIREqualizerContext *av_restrict s, const float *av_restrict kernel_buf, FFTComplex *av_restrict conv_buf,
OverlapIndex *av_restrict idx, float *av_restrict data0, float *av_restrict data1, int nsamples)
{
@ -310,22 +361,32 @@ static void dump_fir(AVFilterContext *ctx, FILE *fp, int ch)
double delay = s->zero_phase ? 0.0 : (double) center / rate;
double vx, ya, yb;
if (!s->min_phase) {
s->analysis_buf[0] *= s->rdft_len/2;
for (x = 1; x <= center; x++) {
s->analysis_buf[x] *= s->rdft_len/2;
s->analysis_buf[s->analysis_rdft_len - x] *= s->rdft_len/2;
}
} else {
for (x = 0; x < s->fir_len; x++)
s->analysis_buf[x] *= s->rdft_len/2;
}
if (ch)
fprintf(fp, "\n\n");
fprintf(fp, "# time[%d] (time amplitude)\n", ch);
if (!s->min_phase) {
for (x = center; x > 0; x--)
fprintf(fp, "%15.10f %15.10f\n", delay - (double) x / rate, (double) s->analysis_buf[s->analysis_rdft_len - x]);
for (x = 0; x <= center; x++)
fprintf(fp, "%15.10f %15.10f\n", delay + (double)x / rate , (double) s->analysis_buf[x]);
} else {
for (x = 0; x < s->fir_len; x++)
fprintf(fp, "%15.10f %15.10f\n", (double)x / rate, (double) s->analysis_buf[x]);
}
av_rdft_calc(s->analysis_rdft, s->analysis_buf);
@ -337,7 +398,9 @@ static void dump_fir(AVFilterContext *ctx, FILE *fp, int ch)
if (xlog)
vx = log2(0.05*vx);
ya = s->dump_buf[i];
yb = s->analysis_buf[i];
yb = s->min_phase && (i > 1) ? hypotf(s->analysis_buf[i], s->analysis_buf[i+1]) : s->analysis_buf[i];
if (s->min_phase)
yb = fabs(yb);
if (ylog) {
ya = 20.0 * log10(fabs(ya));
yb = 20.0 * log10(fabs(yb));
@ -487,6 +550,53 @@ enum VarOffset {
VAR_NB
};
static void generate_min_phase_kernel(FIREqualizerContext *s, float *rdft_buf)
{
int k, cepstrum_len = s->cepstrum_len, rdft_len = s->rdft_len;
double norm = 2.0 / cepstrum_len;
memset(s->cepstrum_buf, 0, cepstrum_len * sizeof(*s->cepstrum_buf));
memcpy(s->cepstrum_buf, rdft_buf, rdft_len/2 * sizeof(*rdft_buf));
memcpy(s->cepstrum_buf + cepstrum_len - rdft_len/2, rdft_buf + rdft_len/2, rdft_len/2 * sizeof(*rdft_buf));
av_rdft_calc(s->cepstrum_rdft, s->cepstrum_buf);
s->cepstrum_buf[0] = log(FFMAX(s->cepstrum_buf[0], 1e-10));
s->cepstrum_buf[1] = log(FFMAX(s->cepstrum_buf[1], 1e-10));
for (k = 2; k < cepstrum_len; k += 2) {
s->cepstrum_buf[k] = log(FFMAX(s->cepstrum_buf[k], 1e-10));
s->cepstrum_buf[k+1] = 0;
}
av_rdft_calc(s->cepstrum_irdft, s->cepstrum_buf);
memset(s->cepstrum_buf + cepstrum_len/2 + 1, 0, (cepstrum_len/2 - 1) * sizeof(*s->cepstrum_buf));
for (k = 1; k < cepstrum_len/2; k++)
s->cepstrum_buf[k] *= 2;
av_rdft_calc(s->cepstrum_rdft, s->cepstrum_buf);
s->cepstrum_buf[0] = exp(s->cepstrum_buf[0] * norm) * norm;
s->cepstrum_buf[1] = exp(s->cepstrum_buf[1] * norm) * norm;
for (k = 2; k < cepstrum_len; k += 2) {
double mag = exp(s->cepstrum_buf[k] * norm) * norm;
double ph = s->cepstrum_buf[k+1] * norm;
s->cepstrum_buf[k] = mag * cos(ph);
s->cepstrum_buf[k+1] = mag * sin(ph);
}
av_rdft_calc(s->cepstrum_irdft, s->cepstrum_buf);
memset(rdft_buf, 0, s->rdft_len * sizeof(*rdft_buf));
memcpy(rdft_buf, s->cepstrum_buf, s->fir_len * sizeof(*rdft_buf));
if (s->dumpfile) {
memset(s->analysis_buf, 0, s->analysis_rdft_len * sizeof(*s->analysis_buf));
memcpy(s->analysis_buf, s->cepstrum_buf, s->fir_len * sizeof(*s->analysis_buf));
}
}
static int generate_kernel(AVFilterContext *ctx, const char *gain, const char *gain_entry)
{
FIREqualizerContext *s = ctx->priv;
@ -549,7 +659,7 @@ static int generate_kernel(AVFilterContext *ctx, const char *gain, const char *g
if (xlog)
vars[VAR_F] = log2(0.05 * vars[VAR_F]);
result = av_expr_eval(gain_expr, vars, ctx);
s->analysis_buf[2*k] = ylog ? pow(10.0, 0.05 * result) : result;
s->analysis_buf[2*k] = ylog ? pow(10.0, 0.05 * result) : s->min_phase ? fabs(result) : result;
s->analysis_buf[2*k+1] = 0.0;
}
@ -604,6 +714,8 @@ static int generate_kernel(AVFilterContext *ctx, const char *gain, const char *g
memset(s->analysis_buf + center + 1, 0, (s->analysis_rdft_len - s->fir_len) * sizeof(*s->analysis_buf));
memcpy(rdft_buf, s->analysis_buf, s->rdft_len/2 * sizeof(*s->analysis_buf));
memcpy(rdft_buf + s->rdft_len/2, s->analysis_buf + s->analysis_rdft_len - s->rdft_len/2, s->rdft_len/2 * sizeof(*s->analysis_buf));
if (s->min_phase)
generate_min_phase_kernel(s, rdft_buf);
av_rdft_calc(s->rdft, rdft_buf);
for (k = 0; k < s->rdft_len; k++) {
@ -616,10 +728,12 @@ static int generate_kernel(AVFilterContext *ctx, const char *gain, const char *g
}
}
if (!s->min_phase) {
rdft_buf[s->rdft_len-1] = rdft_buf[1];
for (k = 0; k < s->rdft_len/2; k++)
rdft_buf[k] = rdft_buf[2*k];
rdft_buf[s->rdft_len/2] = rdft_buf[s->rdft_len-1];
}
if (dump_fp)
dump_fir(ctx, dump_fp, ch);
@ -670,6 +784,25 @@ static int config_input(AVFilterLink *inlink)
if (s->fft2 && !s->multi && inlink->channels > 1 && !(s->fft_ctx = av_fft_init(rdft_bits, 0)))
return AVERROR(ENOMEM);
if (s->min_phase) {
int cepstrum_bits = rdft_bits + 2;
if (cepstrum_bits > RDFT_BITS_MAX) {
av_log(ctx, AV_LOG_ERROR, "too large delay, please decrease it.\n");
return AVERROR(EINVAL);
}
cepstrum_bits = FFMIN(RDFT_BITS_MAX, cepstrum_bits + 1);
s->cepstrum_rdft = av_rdft_init(cepstrum_bits, DFT_R2C);
s->cepstrum_irdft = av_rdft_init(cepstrum_bits, IDFT_C2R);
if (!s->cepstrum_rdft || !s->cepstrum_irdft)
return AVERROR(ENOMEM);
s->cepstrum_len = 1 << cepstrum_bits;
s->cepstrum_buf = av_malloc_array(s->cepstrum_len, sizeof(*s->cepstrum_buf));
if (!s->cepstrum_buf)
return AVERROR(ENOMEM);
}
for ( ; rdft_bits <= RDFT_BITS_MAX; rdft_bits++) {
s->analysis_rdft_len = 1 << rdft_bits;
if (inlink->sample_rate <= s->accuracy * s->analysis_rdft_len)
@ -712,6 +845,7 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
FIREqualizerContext *s = ctx->priv;
int ch;
if (!s->min_phase) {
for (ch = 0; ch + 1 < inlink->channels && s->fft_ctx; ch += 2) {
fast_convolute2(s, s->kernel_buf, (FFTComplex *)(s->conv_buf + 2 * ch * s->rdft_len),
s->conv_idx + ch, (float *) frame->extended_data[ch],
@ -723,11 +857,18 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
s->conv_buf + 2 * ch * s->rdft_len, s->conv_idx + ch,
(float *) frame->extended_data[ch], frame->nb_samples);
}
} else {
for (ch = 0; ch < inlink->channels; ch++) {
fast_convolute_nonlinear(s, s->kernel_buf + (s->multi ? ch * s->rdft_len : 0),
s->conv_buf + 2 * ch * s->rdft_len, s->conv_idx + ch,
(float *) frame->extended_data[ch], frame->nb_samples);
}
}
s->next_pts = AV_NOPTS_VALUE;
if (frame->pts != AV_NOPTS_VALUE) {
s->next_pts = frame->pts + av_rescale_q(frame->nb_samples, av_make_q(1, inlink->sample_rate), inlink->time_base);
if (s->zero_phase)
if (s->zero_phase && !s->min_phase)
frame->pts -= av_rescale_q(s->fir_len/2, av_make_q(1, inlink->sample_rate), inlink->time_base);
}
s->frame_nsamples_max = FFMAX(s->frame_nsamples_max, frame->nb_samples);