janus-pp-rec: improve DTX detection (#3488)

meetecho · Jan 17, 2025 · 3cdd6ff · 3cdd6ff
1 parent bbe648d
commit 3cdd6ff
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Showing 3 changed files with 40 additions and 21 deletions.
diff --git a/src/postprocessing/janus-pp-rec.c b/src/postprocessing/janus-pp-rec.c
@@ -1310,6 +1310,7 @@ int main(int argc, char *argv[]) {
 
 					/* Update current packet ts with new ts */
 					tmp->ts = new_ts;
+					tmp->restamped = 1;
 
 					JANUS_LOG(LOG_WARN, "Timestamp gap detected. Restamping packets from here. Seq: %d\n", tmp->seq);
 					JANUS_LOG(LOG_INFO, "latency=%.2f mavg=%.2f original_ts=%.ld new_ts=%.ld offset=%.ld\n", current_latency, moving_avg_latency, original_ts, tmp->ts, restamping_offset);

diff --git a/src/postprocessing/pp-opus.c b/src/postprocessing/pp-opus.c
@@ -107,7 +107,7 @@ int janus_pp_opus_process(FILE *file, janus_pp_frame_packet *list, gboolean rest
 	janus_pp_frame_packet *tmp = list;
 	long int offset = 0;
 	int bytes = 0, len = 0, last_seq = 0;
-	uint64_t pos = 0, nextPos = 0;
+	uint64_t pos = 0;
 	double ts = 0.0;
 	uint8_t *buffer = g_malloc0(1500);
 
@@ -251,21 +251,37 @@ int janus_pp_opus_process(FILE *file, janus_pp_frame_packet *list, gboolean rest
 	AVRational timebase = {1, 48000};
 
 	while(*working && tmp != NULL) {
-		/* if restamping is being used, do not evaluate the sequence number jump */
-		if(tmp->prev != NULL && ((tmp->ts - tmp->prev->ts)/48/20 > 1) && (restamping || (tmp->seq != tmp->prev->seq+1))) {
-			JANUS_LOG(LOG_WARN, "Lost a packet here? (got seq %"SCNu16" after %"SCNu16", time ~%"SCNu64"s)\n",
-				tmp->seq, tmp->prev->seq, (tmp->ts-list->ts)/48000);
+		if(tmp->prev != NULL && ((tmp->ts - tmp->prev->ts)/48 > 20)) {
+			int silence_count = 0;
+			if(tmp->seq != tmp->prev->seq+1) {
+				/* Packet Lost */
+				JANUS_LOG(LOG_WARN, "Lost a packet here? (got seq %"SCNu16" after %"SCNu16", time ~%"SCNu64"s)\n",
+					tmp->seq, tmp->prev->seq, (tmp->ts-list->ts)/48000);
+				/* insert 20ms silence packets before the current packet */
+				silence_count = (tmp->ts - tmp->prev->ts)/48/20 - 1;
+			} else if(restamping && tmp->restamped == 1) {
+				/* Packet restamped due to RTP clock issues */
+				JANUS_LOG(LOG_WARN, "Restamped packet detected (got seq %"SCNu16" after %"SCNu16", time ~%"SCNu64"s)\n",
+					tmp->seq, tmp->prev->seq, (tmp->ts-list->ts)/48000);
+				/* insert 20ms silence packets before the current packet */
+				silence_count = (tmp->ts - tmp->prev->ts)/48/20 - 1;
+			} else {
+				/* plen > 20 ms, DTX ?*/
+				JANUS_LOG(LOG_WARN, "DTX packet detected (got seq %"SCNu16" after %"SCNu16", time ~%"SCNu64"s)\n",
+					tmp->seq, tmp->prev->seq, (tmp->ts-list->ts)/48000);
+				/* insert 20ms silence packets for the whole DTX duration */
+				silence_count = (tmp->ts - tmp->prev->ts)/48/20;
+				/* drop this packet since it's DTX silence */
+				tmp->drop = 1;
+			}
 			/* use ts differ to insert silence packet */
-			int silence_count = (tmp->ts - tmp->prev->ts)/48/20 - 1;
 			pos = (tmp->prev->ts - list->ts) / 48 / 20 + 1;
 			JANUS_LOG(LOG_WARN, "[FILL] pos: %06"SCNu64", writing silences (count=%d)\n", pos, silence_count);
 			int i=0;
 			pos = tmp->prev->ts - list->ts;
 			for(i=0; i<silence_count; i++) {
 				pos += OPUS_PACKET_DURATION;
-				if(tmp->next != NULL)
-					nextPos = tmp->next->ts - list->ts;
-				if(pos >= nextPos) {
+				if(tmp->next != NULL && pos >= (tmp->next->ts - list->ts)) {
 					JANUS_LOG(LOG_WARN, "[SKIP] pos: %06" SCNu64 ", skipping remaining silence\n", pos / 48 / 20 + 1);
 					break;
 				}
@@ -280,7 +296,7 @@ int janus_pp_opus_process(FILE *file, janus_pp_frame_packet *list, gboolean rest
 
 				int res = av_write_frame(fctx, pkt);
 				if(res < 0) {
-					JANUS_LOG(LOG_ERR, "Error writing video frame to file... (error %d, %s)\n",
+					JANUS_LOG(LOG_ERR, "Error writing audio frame to file... (error %d, %s)\n",
 						res, av_err2str(res));
 				}
 			}
@@ -321,6 +337,7 @@ int janus_pp_opus_process(FILE *file, janus_pp_frame_packet *list, gboolean rest
 		if(tmp->seq < last_seq) {
 			last_seq = tmp->seq;
 		}
+		pos = tmp->prev != NULL ? ((tmp->prev->ts - list->ts) / 48 / 20 + 1) : 0;
 		JANUS_LOG(LOG_VERB, "pos: %06"SCNu64", writing %d bytes out of %d (seq=%"SCNu16", step=%"SCNu16", ts=%"SCNu64", time=%"SCNu64"s)\n",
 			pos, bytes, tmp->len, tmp->seq, diff, tmp->ts, (tmp->ts-list->ts)/48000);
 #ifdef FF_API_INIT_PACKET

diff --git a/src/postprocessing/pp-rtp.h b/src/postprocessing/pp-rtp.h
@@ -57,17 +57,18 @@ typedef struct janus_pp_rtp_header_extension {
 
 typedef struct janus_pp_frame_packet {
 	janus_pp_rtp_header *header; /* Pointer to RTP header */
-	int version;	/* Version of the .mjr file (2=has timestamps) */
-	uint32_t p_ts;	/* Packet timestamp as saved by Janus (if available) */
-	uint16_t seq;	/* RTP Sequence number */
-	uint64_t ts;	/* RTP Timestamp */
-	uint16_t len;	/* Length of the data */
-	int pt;			/* Payload type of the data */
-	long offset;	/* Offset of the data in the file */
-	int skip;		/* Bytes to skip, besides the RTP header */
-	uint8_t drop;	/* Whether this packet can be dropped (e.g., padding)*/
-	int audiolevel;	/* Value of audio level in RTP extension, if parsed */
-	int rotation;	/* Value of rotation in RTP extension, if parsed */
+	int version;		/* Version of the .mjr file (2=has timestamps) */
+	uint32_t p_ts;		/* Packet timestamp as saved by Janus (if available) */
+	uint16_t seq;		/* RTP Sequence number */
+	uint64_t ts;		/* RTP Timestamp */
+	uint16_t len;		/* Length of the data */
+	int pt;				/* Payload type of the data */
+	long offset;		/* Offset of the data in the file */
+	int skip;			/* Bytes to skip, besides the RTP header */
+	uint8_t drop;	  	/* Whether this packet can be dropped (e.g., padding)*/
+	uint8_t restamped;	/* Whether this packet has been restamped */
+	int audiolevel;		/* Value of audio level in RTP extension, if parsed */
+	int rotation;		/* Value of rotation in RTP extension, if parsed */
 	struct janus_pp_frame_packet *next;
 	struct janus_pp_frame_packet *prev;
 } janus_pp_frame_packet;