avfilter/af_astats: implement recalculation of stats after each X frames

Signed-off-by: Paul B Mahol <onemda@gmail.com>
This commit is contained in:
Paul B Mahol 2015-07-01 08:03:19 +00:00
parent d3836b603e
commit c0d676f977
1 changed files with 26 additions and 7 deletions

View File

@ -45,6 +45,8 @@ typedef struct {
double time_constant;
double mult;
int metadata;
int reset_count;
int nb_frames;
} AudioStatsContext;
#define OFFSET(x) offsetof(AudioStatsContext, x)
@ -53,6 +55,7 @@ typedef struct {
static const AVOption astats_options[] = {
{ "length", "set the window length", OFFSET(time_constant), AV_OPT_TYPE_DOUBLE, {.dbl=.05}, .01, 10, FLAGS },
{ "metadata", "inject metadata in the filtergraph", OFFSET(metadata), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS },
{ "reset", "recalculate stats after this many frames", OFFSET(reset_count), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS },
{ NULL }
};
@ -88,10 +91,23 @@ static int query_formats(AVFilterContext *ctx)
return ff_set_common_samplerates(ctx, formats);
}
static void reset_stats(AudioStatsContext *s)
{
int c;
memset(s->chstats, 0, sizeof(*s->chstats));
for (c = 0; c < s->nb_channels; c++) {
ChannelStats *p = &s->chstats[c];
p->min = p->min_sigma_x2 = DBL_MAX;
p->max = p->max_sigma_x2 = DBL_MIN;
}
}
static int config_output(AVFilterLink *outlink)
{
AudioStatsContext *s = outlink->src->priv;
int c;
s->chstats = av_calloc(sizeof(*s->chstats), outlink->channels);
if (!s->chstats)
@ -100,12 +116,7 @@ static int config_output(AVFilterLink *outlink)
s->mult = exp((-1 / s->time_constant / outlink->sample_rate));
s->tc_samples = 5 * s->time_constant * outlink->sample_rate + .5;
for (c = 0; c < s->nb_channels; c++) {
ChannelStats *p = &s->chstats[c];
p->min = p->min_sigma_x2 = DBL_MAX;
p->max = p->max_sigma_x2 = DBL_MIN;
}
reset_stats(s);
return 0;
}
@ -251,6 +262,14 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
if (s->metadata)
set_metadata(s, metadata);
if (s->reset_count > 0) {
s->nb_frames++;
if (s->nb_frames >= s->reset_count) {
reset_stats(s);
s->nb_frames = 0;
}
}
return ff_filter_frame(inlink->dst->outputs[0], buf);
}