avfilter/avf_showfreqs: make minimum amplitude for log scaler configurable

This commit is contained in:
Paul B Mahol 2016-08-17 21:56:42 +02:00
parent 345c252e9c
commit 5ee5f4b13c
2 changed files with 8 additions and 1 deletions

View File

@ -16563,6 +16563,9 @@ It accepts the following values:
@end table
Default is @code{combined}.
@item minamp
Set minimum amplitude used in @code{log} amplitude scaler.
@end table
@anchor{showspectrum}

View File

@ -18,6 +18,7 @@
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <float.h>
#include <math.h>
#include "libavcodec/avfft.h"
@ -53,6 +54,7 @@ typedef struct ShowFreqsContext {
float **avg_data;
float *window_func_lut;
float overlap;
float minamp;
int hop_size;
int nb_channels;
int nb_freq;
@ -122,6 +124,7 @@ static const AVOption showfreqs_options[] = {
{ "cmode", "set channel mode", OFFSET(cmode), AV_OPT_TYPE_INT, {.i64=COMBINED}, 0, NB_CMODES-1, FLAGS, "cmode" },
{ "combined", "show all channels in same window", 0, AV_OPT_TYPE_CONST, {.i64=COMBINED}, 0, 0, FLAGS, "cmode" },
{ "separate", "show each channel in own window", 0, AV_OPT_TYPE_CONST, {.i64=SEPARATE}, 0, 0, FLAGS, "cmode" },
{ "minamp", "set minimum amplitude", OFFSET(minamp), AV_OPT_TYPE_FLOAT, {.dbl=1e-6}, FLT_MIN, 1e-6, FLAGS },
{ NULL }
};
@ -285,6 +288,7 @@ static inline void plot_freq(ShowFreqsContext *s, int ch,
AVFrame *out, AVFilterLink *outlink)
{
const int w = s->w;
const float min = s->minamp;
const float avg = s->avg_data[ch][f];
const float bsize = get_bsize(s, f);
const int sx = get_sx(s, f);
@ -299,7 +303,7 @@ static inline void plot_freq(ShowFreqsContext *s, int ch,
a = 1.0 - cbrt(a);
break;
case AS_LOG:
a = log(av_clipd(a, 1e-6, 1)) / log(1e-6);
a = log(av_clipd(a, min, 1)) / log(min);
break;
case AS_LINEAR:
a = 1.0 - a;