On Mon, Oct 12, 2020 at 07:01:17PM +0200, Romane Lafon wrote:
> This patch extends aphasemeter to detect out of phase or mono sequences in
> stereo streams. Same patch as v8, but doc updated with the latest master
> branch.
>
probably fine, gonna apply, if I forgot, ping me.
> Regards,
> Romane
> From 10bcfc2652514e9e212c5a643e83f6614c8017bd Mon Sep 17 00:00:00 2001
> From: Romane Lafon <rom...@nomalab.com>
> Date: Mon, 12 Oct 2020 18:14:55 +0200
> Subject: [PATCH] avfilter/avf_aphasemeter: Add out of phase and mono detection
>
> Signed-off-by: Romane Lafon <rom...@nomalab.com>
> ---
> doc/filters.texi | 33 ++++++++++
> libavfilter/avf_aphasemeter.c | 118 +++++++++++++++++++++++++++++++++-
> 2 files changed, 150 insertions(+), 1 deletion(-)
>
> diff --git a/doc/filters.texi b/doc/filters.texi
> index 8404f4fb9a..27ff814f3e 100644
> --- a/doc/filters.texi
> +++ b/doc/filters.texi
> @@ -23340,6 +23340,39 @@ 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
> diff --git a/libavfilter/avf_aphasemeter.c b/libavfilter/avf_aphasemeter.c
> index 31fc8b1b3f..61da9a90b6 100644
> --- a/libavfilter/avf_aphasemeter.c
> +++ b/libavfilter/avf_aphasemeter.c
> @@ -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);
> }
>
> --
> 2.20.1
>
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