avfilter/avf_aphasemeter: add out of phase and mono detection

Extend aphasemeter to detect out of phase or mono sequences in
stereo streams.

Signed-off-by: Romane Lafon <romane@nomalab.com>
pull/356/head
Romane Lafon 4 years ago committed by Paul B Mahol
parent 6707152f08
commit d60927b676
  1. 33
      doc/filters.texi
  2. 118
      libavfilter/avf_aphasemeter.c

@ -23356,6 +23356,39 @@ Set color which will be used for drawing median phase. If color is
Enable video output. Default is enabled.
@end table
@subsection phasing detection
The filter also detects out of phase and mono sequences in stereo streams.
It logs the sequence start, end and duration when it lasts longer or as long as the minimum set.
The filter accepts the following options for this detection:
@table @option
@item phasing
Enable mono and out of phase detection. Default is disabled.
@item tolerance, t
Set phase tolerance for mono detection, in amplitude ratio. Default is @code{0}.
Allowed range is @code{[0, 1]}.
@item angle, a
Set angle threshold for out of phase detection, in degree. Default is @code{170}.
Allowed range is @code{[90, 180]}.
@item duration, d
Set mono or out of phase duration until notification, expressed in seconds. Default is @code{2}.
@end table
@subsection Examples
@itemize
@item
Complete example with @command{ffmpeg} to detect 1 second of mono with 0.001 phase tolerance:
@example
ffmpeg -i stereo.wav -af aphasemeter=video=0:phasing=1:duration=1:tolerance=0.001 -f null -
@end example
@end itemize
@section avectorscope
Convert input audio to a video output, representing the audio vector

@ -28,26 +28,43 @@
#include "libavutil/intreadwrite.h"
#include "libavutil/opt.h"
#include "libavutil/parseutils.h"
#include "libavutil/timestamp.h"
#include "avfilter.h"
#include "formats.h"
#include "audio.h"
#include "video.h"
#include "internal.h"
#include "float.h"
typedef struct AudioPhaseMeterContext {
const AVClass *class;
AVFrame *out;
int do_video;
int do_phasing_detection;
int w, h;
AVRational frame_rate;
int contrast[4];
uint8_t *mpc_str;
uint8_t mpc[4];
int draw_median_phase;
int is_mono;
int is_out_phase;
int start_mono_presence;
int start_out_phase_presence;
float tolerance;
float angle;
float phase;
AVRational time_base;
int64_t duration;
int64_t frame_end;
int64_t mono_idx[2];
int64_t out_phase_idx[2];
} AudioPhaseMeterContext;
#define MAX_DURATION (24*60*60*1000000LL)
#define OFFSET(x) offsetof(AudioPhaseMeterContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
#define get_duration(index) (index[1] - index[0])
static const AVOption aphasemeter_options[] = {
{ "rate", "set video rate", OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str="25"}, 0, INT_MAX, FLAGS },
@ -59,6 +76,13 @@ static const AVOption aphasemeter_options[] = {
{ "bc", "set blue contrast", OFFSET(contrast[2]), AV_OPT_TYPE_INT, {.i64=1}, 0, 255, FLAGS },
{ "mpc", "set median phase color", OFFSET(mpc_str), AV_OPT_TYPE_STRING, {.str = "none"}, 0, 0, FLAGS },
{ "video", "set video output", OFFSET(do_video), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, FLAGS },
{ "phasing", "set mono and out-of-phase detection output", OFFSET(do_phasing_detection), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, FLAGS },
{ "tolerance", "set phase tolerance for mono detection", OFFSET(tolerance), AV_OPT_TYPE_FLOAT, {.dbl = 0.}, 0, 1, FLAGS },
{ "t", "set phase tolerance for mono detection", OFFSET(tolerance), AV_OPT_TYPE_FLOAT, {.dbl = 0.}, 0, 1, FLAGS },
{ "angle", "set angle threshold for out-of-phase detection", OFFSET(angle), AV_OPT_TYPE_FLOAT, {.dbl = 170.}, 90, 180, FLAGS },
{ "a", "set angle threshold for out-of-phase detection", OFFSET(angle), AV_OPT_TYPE_FLOAT, {.dbl = 170.}, 90, 180, FLAGS },
{ "duration", "set minimum mono or out-of-phase duration in seconds", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64=2000000}, 0, MAX_DURATION, FLAGS },
{ "d", "set minimum mono or out-of-phase duration in seconds", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64=2000000}, 0, MAX_DURATION, FLAGS },
{ NULL }
};
@ -104,6 +128,7 @@ static int config_input(AVFilterLink *inlink)
AVFilterContext *ctx = inlink->dst;
AudioPhaseMeterContext *s = ctx->priv;
int nb_samples;
s->duration = av_rescale(s->duration, inlink->sample_rate, AV_TIME_BASE);
if (s->do_video) {
nb_samples = FFMAX(1, av_rescale(inlink->sample_rate, s->frame_rate.den, s->frame_rate.num));
@ -140,6 +165,76 @@ static inline int get_x(float phase, int w)
return (phase + 1.) / 2. * (w - 1);
}
static inline void add_metadata(AVFrame *insamples, const char *key, char *value)
{
char buf[128];
snprintf(buf, sizeof(buf), "lavfi.aphasemeter.%s", key);
av_dict_set(&insamples->metadata, buf, value, 0);
}
static inline void update_mono_detection(AudioPhaseMeterContext *s, AVFrame *insamples, int mono_measurement)
{
int64_t mono_duration;
if (!s->is_mono && mono_measurement) {
s->is_mono = 1;
s->start_mono_presence = 1;
s->mono_idx[0] = insamples->pts;
}
if (s->is_mono && mono_measurement && s->start_mono_presence) {
s->mono_idx[1] = s->frame_end;
mono_duration = get_duration(s->mono_idx);
if (mono_duration >= s->duration) {
add_metadata(insamples, "mono_start", av_ts2timestr(s->mono_idx[0], &s->time_base));
av_log(s, AV_LOG_INFO, "mono_start: %s\n", av_ts2timestr(s->mono_idx[0], &s->time_base));
s->start_mono_presence = 0;
}
}
if (s->is_mono && !mono_measurement) {
s->mono_idx[1] = insamples ? insamples->pts : s->frame_end;
mono_duration = get_duration(s->mono_idx);
if (mono_duration >= s->duration) {
if (insamples) {
add_metadata(insamples, "mono_end", av_ts2timestr(s->mono_idx[1], &s->time_base));
add_metadata(insamples, "mono_duration", av_ts2timestr(mono_duration, &s->time_base));
}
av_log(s, AV_LOG_INFO, "mono_end: %s | mono_duration: %s\n", av_ts2timestr(s->mono_idx[1], &s->time_base), av_ts2timestr(mono_duration, &s->time_base));
}
s->is_mono = 0;
}
}
static inline void update_out_phase_detection(AudioPhaseMeterContext *s, AVFrame *insamples, int out_phase_measurement)
{
int64_t out_phase_duration;
if (!s->is_out_phase && out_phase_measurement) {
s->is_out_phase = 1;
s->start_out_phase_presence = 1;
s->out_phase_idx[0] = insamples->pts;
}
if (s->is_out_phase && out_phase_measurement && s->start_out_phase_presence) {
s->out_phase_idx[1] = s->frame_end;
out_phase_duration = get_duration(s->out_phase_idx);
if (out_phase_duration >= s->duration) {
add_metadata(insamples, "out_phase_start", av_ts2timestr(s->out_phase_idx[0], &s->time_base));
av_log(s, AV_LOG_INFO, "out_phase_start: %s\n", av_ts2timestr(s->out_phase_idx[0], &s->time_base));
s->start_out_phase_presence = 0;
}
}
if (s->is_out_phase && !out_phase_measurement) {
s->out_phase_idx[1] = insamples ? insamples->pts : s->frame_end;
out_phase_duration = get_duration(s->out_phase_idx);
if (out_phase_duration >= s->duration) {
if (insamples) {
add_metadata(insamples, "out_phase_end", av_ts2timestr(s->out_phase_idx[1], &s->time_base));
add_metadata(insamples, "out_phase_duration", av_ts2timestr(out_phase_duration, &s->time_base));
}
av_log(s, AV_LOG_INFO, "out_phase_end: %s | out_phase_duration: %s\n", av_ts2timestr(s->out_phase_idx[1], &s->time_base), av_ts2timestr(out_phase_duration, &s->time_base));
}
s->is_out_phase = 0;
}
}
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
{
AVFilterContext *ctx = inlink->dst;
@ -154,6 +249,10 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
AVFrame *out;
uint8_t *dst;
int i;
int mono_measurement;
int out_phase_measurement;
float tolerance = 1.0f - s->tolerance;
float angle = cosf(s->angle/180.0f*M_PI);
if (s->do_video && (!s->out || s->out->width != outlink->w ||
s->out->height != outlink->h)) {
@ -193,6 +292,7 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
fphase += phase;
}
fphase /= in->nb_samples;
s->phase = fphase;
if (s->do_video) {
if (s->draw_median_phase) {
@ -209,7 +309,19 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
uint8_t value[128];
snprintf(value, sizeof(value), "%f", fphase);
av_dict_set(metadata, "lavfi.aphasemeter.phase", value, 0);
add_metadata(in, "phase", value);
}
if (s->do_phasing_detection) {
s->time_base = inlink->time_base;
s->frame_end = in->pts + av_rescale_q(in->nb_samples,
(AVRational){ 1, in->sample_rate }, inlink->time_base);
mono_measurement = (tolerance - fphase) < FLT_EPSILON;
out_phase_measurement = (angle - fphase) > FLT_EPSILON;
update_mono_detection(s, in, mono_measurement);
update_out_phase_detection(s, in, out_phase_measurement);
}
if (s->do_video) {
@ -228,6 +340,10 @@ static av_cold void uninit(AVFilterContext *ctx)
{
AudioPhaseMeterContext *s = ctx->priv;
if (s->do_phasing_detection) {
update_mono_detection(s, NULL, 0);
update_out_phase_detection(s, NULL, 0);
}
av_frame_free(&s->out);
}

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