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avfilter/showcqt: add and extend tlength and volume options 

Add a tlength option with frequency and timeclamp variable

Add to the volume option support for frequency and timeclamp variable,
   a_weighting, b_weighting and c_weighting functions

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Muhammad Faiz 2014-08-08 21:58:35 +07:00 committed by Michael Niedermayer
parent d1e750cd51
commit 94494dab91
2 changed files with 119 additions and 10 deletions
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42
doc/filters.texi
View File

@ -10515,8 +10515,34 @@ The filter accepts the following options:
@table @option
@item volume
Specify the transform volume (multiplier). Acceptable value is [1.0, 100.0].
Default value is @code{16.0}.
Specify transform volume (multiplier) expression. The expression can contain
variables:
@table @option
@item frequency, freq, f
the frequency where transform is evaluated
@item timeclamp, tc
value of timeclamp option
@end table
and functions:
@table @option
@item a_weighting(f)
A-weighting of equal loudness
@item b_weighting(f)
B-weighting of equal loudness
@item c_weighting(f)
C-weighting of equal loudness
@end table
Default value is @code{16}.
@item tlength
Specify transform length expression. The expression can contain variables:
@table @option
@item frequency, freq, f
the frequency where transform is evaluated
@item timeclamp, tc
value of timeclamp option
@end table
Default value is @code{384/f*tc/(384/f+tc)}.
@item timeclamp
Specify the transform timeclamp. At low frequency, there is trade-off between
@ -10587,6 +10613,18 @@ ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*
asplit[a][out1]; [a] showcqt=timeclamp=0.5 [out0]'
@end example
@item
B-weighting of equal loudness
@example
volume=16*b_weighting(f)
@end example
@item
Lower Q factor
@example
tlength=100/f*tc/(100/f+tc)
@end example
@end itemize
@section showspectrum

87
libavfilter/avf_showcqt.c
View File

@ -26,6 +26,7 @@
#include "libavutil/xga_font_data.h"
#include "libavutil/qsort.h"
#include "libavutil/time.h"
#include "libavutil/eval.h"
#include "avfilter.h"
#include "internal.h"
@ -49,6 +50,10 @@
#define SPECTOGRAM_START (VIDEO_HEIGHT-SPECTOGRAM_HEIGHT)
#define BASE_FREQ 20.051392800492
#define COEFF_CLAMP 1.0e-4
#define TLENGTH_MIN 0.001
#define TLENGTH_DEFAULT "384/f*tc/(384/f+tc)"
#define VOLUME_MIN 1e-10
#define VOLUME_MAX 100.0
typedef struct {
FFTSample value;
@ -75,7 +80,8 @@ typedef struct {
int fft_bits;
int req_fullfilled;
int remaining_fill;
double volume;
char *tlength;
char *volume;
double timeclamp; /* lower timeclamp, time-accurate, higher timeclamp, freq-accurate (at low freq)*/
float coeffclamp; /* lower coeffclamp, more precise, higher coeffclamp, faster */
int fullhd; /* if true, output video is at full HD resolution, otherwise it will be halved */
@ -88,7 +94,8 @@ typedef struct {
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
static const AVOption showcqt_options[] = {
{ "volume", "set volume", OFFSET(volume), AV_OPT_TYPE_DOUBLE, { .dbl = 16 }, 0.1, 100, FLAGS },
{ "volume", "set volume", OFFSET(volume), AV_OPT_TYPE_STRING, { .str = "16" }, CHAR_MIN, CHAR_MAX, FLAGS },
{ "tlength", "set transform length", OFFSET(tlength), AV_OPT_TYPE_STRING, { .str = TLENGTH_DEFAULT }, CHAR_MIN, CHAR_MAX, FLAGS },
{ "timeclamp", "set timeclamp", OFFSET(timeclamp), AV_OPT_TYPE_DOUBLE, { .dbl = 0.17 }, 0.1, 1.0, FLAGS },
{ "coeffclamp", "set coeffclamp", OFFSET(coeffclamp), AV_OPT_TYPE_FLOAT, { .dbl = 1 }, 0.1, 10, FLAGS },
{ "gamma", "set gamma", OFFSET(gamma), AV_OPT_TYPE_FLOAT, { .dbl = 3 }, 1, 7, FLAGS },
@ -246,6 +253,28 @@ static void load_freetype_font(AVFilterContext *ctx)
}
#endif
static double a_weighting(void *p, double f)
{
double ret = 12200.0*12200.0 * (f*f*f*f);
ret /= (f*f + 20.6*20.6) * (f*f + 12200.0*12200.0) *
sqrt((f*f + 107.7*107.7) * (f*f + 737.9*737.9));
return ret;
}
static double b_weighting(void *p, double f)
{
double ret = 12200.0*12200.0 * (f*f*f);
ret /= (f*f + 20.6*20.6) * (f*f + 12200.0*12200.0) * sqrt(f*f + 158.5*158.5);
return ret;
}
static double c_weighting(void *p, double f)
{
double ret = 12200.0*12200.0 * (f*f);
ret /= (f*f + 20.6*20.6) * (f*f + 12200.0*12200.0);
return ret;
}
static inline int qsort_sparsecoeff(const SparseCoeff *a, const SparseCoeff *b)
{
if (fabsf(a->value) >= fabsf(b->value))
@ -259,7 +288,11 @@ static int config_output(AVFilterLink *outlink)
AVFilterContext *ctx = outlink->src;
AVFilterLink *inlink = ctx->inputs[0];
ShowCQTContext *s = ctx->priv;
int fft_len, k, x, y;
AVExpr *tlength_expr, *volume_expr;
static const char * const expr_vars[] = { "timeclamp", "tc", "frequency", "freq", "f", NULL };
static const char * const expr_func_names[] = { "a_weighting", "b_weighting", "c_weighting", NULL };
static double (* const expr_funcs[])(void *, double) = { a_weighting, b_weighting, c_weighting, NULL };
int fft_len, k, x, y, ret;
int num_coeffs = 0;
int rate = inlink->sample_rate;
double max_len = rate * (double) s->timeclamp;
@ -307,12 +340,22 @@ static int config_output(AVFilterLink *outlink)
av_log(ctx, AV_LOG_INFO, "Calculating spectral kernel, please wait\n");
start_time = av_gettime_relative();
ret = av_expr_parse(&tlength_expr, s->tlength, expr_vars, NULL, NULL, NULL, NULL, 0, ctx);
if (ret < 0)
return ret;
ret = av_expr_parse(&volume_expr, s->volume, expr_vars, expr_func_names,
expr_funcs, NULL, NULL, 0, ctx);
if (ret < 0) {
av_expr_free(tlength_expr);
return ret;
}
for (k = 0; k < VIDEO_WIDTH; k++) {
int hlen = fft_len >> 1;
float total = 0;
float partial = 0;
double freq = BASE_FREQ * exp2(k * (1.0/192.0));
double tlen = rate * (24.0 * 16.0) /freq;
double tlen, tlength, volume;
double expr_vars_val[] = { s->timeclamp, s->timeclamp, freq, freq, freq, 0 };
/* a window function from Albert H. Nuttall,
* "Some Windows with Very Good Sidelobe Behavior"
* -93.32 dB peak sidelobe and 18 dB/octave asymptotic decay
@ -324,10 +367,33 @@ static int config_output(AVFilterLink *outlink)
double sv_step, cv_step, sv, cv;
double sw_step, cw_step, sw, cw, w;
tlen = tlen * max_len / (tlen + max_len);
tlength = av_expr_eval(tlength_expr, expr_vars_val, NULL);
if (isnan(tlength)) {
av_log(ctx, AV_LOG_WARNING, "at freq %g: tlength is nan, setting it to %g\n", freq, s->timeclamp);
tlength = s->timeclamp;
} else if (tlength < TLENGTH_MIN) {
av_log(ctx, AV_LOG_WARNING, "at freq %g: tlength is %g, setting it to %g\n", freq, tlength, TLENGTH_MIN);
tlength = TLENGTH_MIN;
} else if (tlength > s->timeclamp) {
av_log(ctx, AV_LOG_WARNING, "at freq %g: tlength is %g, setting it to %g\n", freq, tlength, s->timeclamp);
tlength = s->timeclamp;
}
volume = FFABS(av_expr_eval(volume_expr, expr_vars_val, NULL));
if (isnan(volume)) {
av_log(ctx, AV_LOG_WARNING, "at freq %g: volume is nan, setting it to 0\n", freq);
volume = VOLUME_MIN;
} else if (volume < VOLUME_MIN) {
volume = VOLUME_MIN;
} else if (volume > VOLUME_MAX) {
av_log(ctx, AV_LOG_WARNING, "at freq %g: volume is %g, setting it to %g\n", freq, volume, VOLUME_MAX);
volume = VOLUME_MAX;
}
tlen = tlength * rate;
s->fft_data[0].re = 0;
s->fft_data[0].im = 0;
s->fft_data[hlen].re = (1.0 + a1 + a2 + a3) * (1.0/tlen) * s->volume * (1.0/fft_len);
s->fft_data[hlen].re = (1.0 + a1 + a2 + a3) * (1.0/tlen) * volume * (1.0/fft_len);
s->fft_data[hlen].im = 0;
sv_step = sv = sin(2.0*M_PI*freq*(1.0/rate));
cv_step = cv = cos(2.0*M_PI*freq*(1.0/rate));
@ -341,7 +407,7 @@ static int config_output(AVFilterLink *outlink)
cw2 = cw * cw - sw * sw;
sw2 = cw * sw + sw * cw;
cw3 = cw * cw2 - sw * sw2;
w = (1.0 + a1 * cw + a2 * cw2 + a3 * cw3) * (1.0/tlen) * s->volume * (1.0/fft_len);
w = (1.0 + a1 * cw + a2 * cw2 + a3 * cw3) * (1.0/tlen) * volume * (1.0/fft_len);
s->fft_data[hlen + x].re = w * cv;
s->fft_data[hlen + x].im = w * sv;
s->fft_data[hlen - x].re = s->fft_data[hlen + x].re;
@ -378,14 +444,19 @@ static int config_output(AVFilterLink *outlink)
s->coeffs_len[k] = fft_len - x;
num_coeffs += s->coeffs_len[k];
s->coeffs[k] = av_malloc_array(s->coeffs_len[k], sizeof(*s->coeffs[k]));
if (!s->coeffs[k])
if (!s->coeffs[k]) {
av_expr_free(volume_expr);
av_expr_free(tlength_expr);
return AVERROR(ENOMEM);
}
for (y = 0; y < s->coeffs_len[k]; y++)
s->coeffs[k][y] = s->coeff_sort[x+y];
break;
}
}
}
av_expr_free(volume_expr);
av_expr_free(tlength_expr);
end_time = av_gettime_relative();
av_log(ctx, AV_LOG_INFO, "Elapsed time %.6f s (fft_len=%u, num_coeffs=%u)\n", 1e-6 * (end_time-start_time), fft_len, num_coeffs);