virtualenv/FFmpeg
1
0
Fork 0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-23 12:43:46 +02:00
Code Issues Releases Activity

avfilter/avf_showvolume: implement basic rms metering mode

Browse Source 
Signed-off-by: Paul B Mahol <onemda@gmail.com>
This commit is contained in:
Paul B Mahol 2018-03-23 22:53:13 +01:00
parent 74c6a6d373
commit 3e3d567761
2 changed files with 48 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
doc/filters.texi
View File

@ -19970,6 +19970,10 @@ step is disabled.
@item p
Set background opacity, allowed range is [0, 1]. Default is 0.
@item m
Set metering mode, can be peak: @code{p} or rms: @code{r},
default is @code{p}.
@end table
@section showwaves

50
libavfilter/avf_showvolume.c
View File

@ -44,6 +44,7 @@ typedef struct ShowVolumeContext {
int orientation;
int step;
float bgopacity;
int mode;
AVFrame *out;
AVExpr *c_expr;
@ -51,6 +52,10 @@ typedef struct ShowVolumeContext {
int draw_volume;
double *values;
uint32_t *color_lut;
float *max;
float rms_factor;
void (*meter)(float *src, int nb_samples, float *max, float factor);
} ShowVolumeContext;
#define OFFSET(x) offsetof(ShowVolumeContext, x)
@ -71,6 +76,9 @@ static const AVOption showvolume_options[] = {
{ "v", "vertical", 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, "orientation" },
{ "s", "set step size", OFFSET(step), AV_OPT_TYPE_INT, {.i64=0}, 0, 5, FLAGS },
{ "p", "set background opacity", OFFSET(bgopacity), AV_OPT_TYPE_FLOAT, {.dbl=0}, 0, 1, FLAGS },
{ "m", "set mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS, "mode" },
{ "p", "peak", 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, FLAGS, "mode" },
{ "r", "rms", 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, FLAGS, "mode" },
{ NULL }
};
@ -120,6 +128,23 @@ static int query_formats(AVFilterContext *ctx)
return 0;
}
static void find_peak(float *src, int nb_samples, float *peak, float factor)
{
int i;
*peak = 0;
for (i = 0; i < nb_samples; i++)
*peak = FFMAX(*peak, FFABS(src[i]));
}
static void find_rms(float *src, int nb_samples, float *rms, float factor)
{
int i;
for (i = 0; i < nb_samples; i++)
*rms += factor * (src[i] * src[i] - *rms);
}
static int config_input(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
@ -138,6 +163,18 @@ static int config_input(AVFilterLink *inlink)
if (!s->color_lut)
return AVERROR(ENOMEM);
s->max = av_calloc(inlink->channels, sizeof(*s->max));
if (!s->max)
return AVERROR(ENOMEM);
s->rms_factor = 10000. / inlink->sample_rate;
switch (s->mode) {
case 0: s->meter = find_peak; break;
case 1: s->meter = find_rms; break;
default: return AVERROR_BUG;
}
return 0;
}
@ -252,10 +289,10 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
for (c = 0; c < inlink->channels; c++) {
float *src = (float *)insamples->extended_data[c];
uint32_t *lut = s->color_lut + s->w * c;
float max = 0;
float max;
for (i = 0; i < insamples->nb_samples; i++)
max = FFMAX(max, src[i]);
s->meter(src, insamples->nb_samples, &s->max[c], s->rms_factor);
max = s->max[c];
s->values[c * VAR_VARS_NB + VAR_VOLUME] = 20.0 * log10(max);
max = av_clipf(max, 0, 1);
@ -280,10 +317,10 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
for (c = 0; c < inlink->channels; c++) {
float *src = (float *)insamples->extended_data[c];
uint32_t *lut = s->color_lut + s->w * c;
float max = 0;
float max;
for (i = 0; i < insamples->nb_samples; i++)
max = FFMAX(max, src[i]);
s->meter(src, insamples->nb_samples, &s->max[c], s->rms_factor);
max = s->max[c];
s->values[c * VAR_VARS_NB + VAR_VOLUME] = 20.0 * log10(max);
max = av_clipf(max, 0, 1);
@ -339,6 +376,7 @@ static av_cold void uninit(AVFilterContext *ctx)
av_expr_free(s->c_expr);
av_freep(&s->values);
av_freep(&s->color_lut);
av_freep(&s->max);
}
static const AVFilterPad showvolume_inputs[] = {