lavfi/silencedetect: export silence info to metadata.

libavfilter/af_silencedetect.c

@@ -78,6 +78,12 @@ static av_cold int init(AVFilterContext *ctx, const char *args)
     return 0;
 }
 
+static char *get_metadata_val(AVFilterBufferRef *insamples, const char *key)
+{
+    AVDictionaryEntry *e = av_dict_get(insamples->metadata, key, NULL, 0);
+    return e && e->value ? e->value : NULL;
+}
+
 static int filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamples)
 {
     int i;
@@ -94,6 +100,7 @@ static int filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamples)
     silence->last_sample_rate = srate;
 
     // TODO: support more sample formats
+    // TODO: document metadata
     if (insamples->format == AV_SAMPLE_FMT_DBL) {
         double *p = (double *)insamples->data[0];
 
@@ -103,16 +110,23 @@ static int filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamples)
                     silence->nb_null_samples++;
                     if (silence->nb_null_samples >= nb_samples_notify) {
                         silence->start = insamples->pts - (int64_t)(silence->duration / av_q2d(inlink->time_base) + .5);
-                        av_log(silence, AV_LOG_INFO,
-                               "silence_start: %s\n", av_ts2timestr(silence->start, &inlink->time_base));
+                        av_dict_set(&insamples->metadata, "lavfi.silence_start",
+                                    av_ts2timestr(silence->start, &inlink->time_base), 0);
+                        av_log(silence, AV_LOG_INFO, "silence_start: %s\n",
+                               get_metadata_val(insamples, "lavfi.silence_start"));
                     }
                 }
             } else {
-                if (silence->start)
+                if (silence->start) {
+                    av_dict_set(&insamples->metadata, "lavfi.silence_end",
+                                av_ts2timestr(insamples->pts, &inlink->time_base), 0);
+                    av_dict_set(&insamples->metadata, "lavfi.silence_duration",
+                                av_ts2timestr(insamples->pts - silence->start, &inlink->time_base), 0);
                     av_log(silence, AV_LOG_INFO,
                            "silence_end: %s | silence_duration: %s\n",
-                           av_ts2timestr(insamples->pts,                  &inlink->time_base),
-                           av_ts2timestr(insamples->pts - silence->start, &inlink->time_base));
+                           get_metadata_val(insamples, "lavfi.silence_end"),
+                           get_metadata_val(insamples, "lavfi.silence_duration"));
+                }
                 silence->nb_null_samples = silence->start = 0;
             }
         }

libavfilter/version.h

@@ -30,7 +30,7 @@
 
 #define LIBAVFILTER_VERSION_MAJOR  3
 #define LIBAVFILTER_VERSION_MINOR  20
-#define LIBAVFILTER_VERSION_MICRO 101
+#define LIBAVFILTER_VERSION_MICRO 102
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
                                                LIBAVFILTER_VERSION_MINOR, \

tests/fate/filter.mak

@@ -53,6 +53,10 @@ FATE_FILTER-$(call ALLYES, FFPROBE LAVFI_INDEV MOVIE_FILTER SELECT_FILTER AVCODE
 fate-filter-metadata-scenedetect: SRC = $(SAMPLES)/svq3/Vertical400kbit.sorenson3.mov
 fate-filter-metadata-scenedetect: CMD = run $(FILTER_METADATA_COMMAND) "movie=$(SRC),select=gt(scene\,.4)"
 
+FATE_FILTER-$(call ALLYES, FFPROBE LAVFI_INDEV AMOVIE_FILTER AMR_DEMUXER AMRWB_DECODER) += fate-filter-metadata-silencedetect
+fate-filter-metadata-silencedetect: SRC = $(SAMPLES)/amrwb/seed-12k65.awb
+fate-filter-metadata-silencedetect: CMD = run $(FILTER_METADATA_COMMAND) "amovie=$(SRC),silencedetect=d=.1"
+
 
 FATE_SAMPLES_AVCONV += $(FATE_FILTER-yes)
 fate-filter: $(FATE_FILTER-yes)