FS-4781 --resolve I added some more code to the jb for seq but I still think the timestamp is more reliable than the seq since we can't know if the rtp is passing over a media proxy who may preserve the timestamps but still rewrite the seq, its more likely the ts shows the more accurate order of the rtp stream

libs/stfu/stfu.c

@@ -69,6 +69,7 @@ struct stfu_instance {
 	struct stfu_queue *old_queue;
     struct stfu_frame *last_frame;
 	uint32_t cur_ts;
+	uint16_t cur_seq;
 	uint32_t last_wr_ts;
 	uint32_t last_rd_ts;
 	uint32_t samples_per_packet;
@@ -361,6 +362,7 @@ void stfu_n_reset(stfu_instance_t *i)
     stfu_n_sync(i, 1);
     
     i->cur_ts = 0;
+    i->cur_seq = 0;
 	i->last_wr_ts = 0;
 	i->last_rd_ts = 0;
 	i->miss_count = 0;	
@@ -650,6 +652,7 @@ stfu_frame_t *stfu_n_read_a_frame(stfu_instance_t *i)
         for (x = 0; x < i->out_queue->array_len; x++) {
             if (!i->out_queue->array[x].was_read) {
                 i->cur_ts = i->out_queue->array[x].ts;
+                i->cur_ts = i->out_queue->array[x].seq;
                 break;
             }
             if (i->cur_ts == 0) {
@@ -661,6 +664,7 @@ stfu_frame_t *stfu_n_read_a_frame(stfu_instance_t *i)
         }
     } else {
         i->cur_ts = i->cur_ts + i->samples_per_packet;
+        i->cur_seq++;
     }
     
     found = stfu_n_find_frame(i, i->out_queue, i->last_wr_ts, i->cur_ts, &rframe);
@@ -679,12 +683,14 @@ stfu_frame_t *stfu_n_read_a_frame(stfu_instance_t *i)
 
     if (found) {
         i->cur_ts = rframe->ts;
+        i->cur_seq = rframe->seq;
     }
 
     if (i->sync_out) {
         if (!found) {
             if ((found = stfu_n_find_any_frame(i, i->out_queue, &rframe))) {
                 i->cur_ts = rframe->ts;
+                i->cur_seq = rframe->seq;
             }
             
             if (stfu_log != null_logger && i->debug) {
@@ -783,6 +789,7 @@ stfu_frame_t *stfu_n_read_a_frame(stfu_instance_t *i)
         rframe->dlen = i->plc_len;
         rframe->pt = i->plc_pt;
         rframe->ts = i->cur_ts;
+        rframe->seq = i->cur_seq;
         i->miss_count++;
         
         if (stfu_log != null_logger && i->debug) {
@@ -799,6 +806,38 @@ stfu_frame_t *stfu_n_read_a_frame(stfu_instance_t *i)
     return rframe;
 }
 
+int32_t stfu_n_copy_next_frame(stfu_instance_t *jb, uint32_t timestamp, uint16_t seq, uint16_t distance, stfu_frame_t *next_frame)
+{
+	uint32_t i = 0, j = 0;
+	stfu_queue_t *queues[] = { jb->out_queue, jb->in_queue, jb->old_queue};
+	stfu_queue_t *queue = NULL;
+	stfu_frame_t *frame = NULL;
+
+	uint32_t target_ts = 0;
+
+	if (!next_frame) return 0;
+
+	target_ts = timestamp + (distance - 1) * jb->samples_per_packet;
+
+	for (i = 0; i < sizeof(queues)/sizeof(queues[0]); i++) {
+		queue = queues[i];
+
+		if (!queue) continue;
+
+		for(j = 0; j < queue->array_size; j++) {
+			frame = &queue->array[j];
+			/* FIXME: ts rollover happened? bad luck */
+			if (frame->ts > target_ts) {
+				memcpy(next_frame, frame, sizeof(stfu_frame_t));
+				return 1;
+			}
+		}
+	}
+
+	return 0;
+}
+
+
 #ifdef WIN32
 #ifndef vsnprintf
 #define vsnprintf _vsnprintf
@@ -927,7 +966,6 @@ static void default_logger(const char *file, const char *func, int line, int lev
 
 }
 
-
 /* For Emacs:
  * Local Variables:
  * mode:c

libs/stfu/stfu.h

@@ -191,6 +191,7 @@ stfu_instance_t *stfu_n_init(uint32_t qlen, uint32_t max_qlen, uint32_t samples_
 stfu_status_t stfu_n_resize(stfu_instance_t *i, uint32_t qlen);
 stfu_status_t stfu_n_add_data(stfu_instance_t *i, uint32_t ts, uint16_t seq, uint32_t pt, void *data, size_t datalen, uint32_t timer_ts, int last);
 stfu_frame_t *stfu_n_read_a_frame(stfu_instance_t *i);
+int32_t stfu_n_copy_next_frame(stfu_instance_t *jb, uint32_t timestamp, uint16_t seq, uint16_t distance, stfu_frame_t *next_frame);
 void stfu_n_reset(stfu_instance_t *i);
 stfu_status_t stfu_n_sync(stfu_instance_t *i, uint32_t packets);
 void stfu_n_call_me(stfu_instance_t *i, stfu_n_call_me_t callback, void *udata);

src/mod/codecs/mod_silk/Makefile

@@ -4,6 +4,7 @@ SILK_BUILDDIR=$(switch_builddir)/libs/silk
 LOCAL_CFLAGS=-I$(SILK_DIR)/src  -I$(SILK_DIR)/interface
 SILK_LA=$(SILK_BUILDDIR)/.libs/libSKP_SILK_SDK.la
 LOCAL_LIBADD=$(SILK_LA)
+LOCAL_OBJS=$(BASE)/libs/stfu/stfu.o
 include $(BASE)/build/modmake.rules
 
 $(SILK_LA): $(SILK_DIR)/.update	

src/mod/codecs/mod_silk/mod_silk.c

@@ -31,6 +31,7 @@
  */
 
 #include "switch.h"
+#include "stfu.h"
 #include "SKP_Silk_SDK_API.h"
 
 SWITCH_MODULE_LOAD_FUNCTION(mod_silk_load);
@@ -321,23 +322,43 @@ static switch_status_t switch_silk_decode(switch_codec_t *codec,
 	SKP_int16 ret, len; 
 	int16_t *target = decoded_data;
 	switch_core_session_t *session = codec->session;
-	stfu_instance_t *jb;
+	stfu_instance_t *jb = NULL;
+
+	SKP_int lost_flag = (*flag & SFF_PLC);
+	stfu_frame_t next_frame;
+
+	SKP_uint8 recbuff[STFU_DATALEN];
+	SKP_int16 reclen;
+	int32_t found_frame;
+	switch_bool_t did_lbrr = SWITCH_FALSE;
 
 	*decoded_data_len = 0;
 
-	if (session) {
+	if (lost_flag) {
-		jb = switch_core_session_get_jb(session, SWITCH_MEDIA_TYPE_AUDIO);
+		if (session) {
-	}
+			jb = switch_core_session_get_jb(session, SWITCH_MEDIA_TYPE_AUDIO);
-
+		}
-	if (jb) {
+		if (jb && codec && codec->cur_frame) {
-		/* to allow compile */
+			for (int i = 1; i <= MAX_LBRR_DELAY; i++) {
-		jb = NULL;
+				found_frame = stfu_n_copy_next_frame(jb, codec->cur_frame->timestamp, codec->cur_frame->seq, i, &next_frame);
+				if (found_frame) {
+					SKP_Silk_SDK_search_for_LBRR(next_frame.data, next_frame.dlen, i, (SKP_uint8*) &recbuff, &reclen);
+					if (reclen) {
+						encoded_data = &recbuff;
+						encoded_data_len = reclen;
+						lost_flag = SKP_FALSE;
+						did_lbrr = SWITCH_TRUE;
+						break;
+					}
+				}
+			}
+		}
 	}
 
 	do {
 		ret = SKP_Silk_SDK_Decode(context->dec_state,
 								  &context->decoder_object,
-								  ((*flag & SFF_PLC)),
+								  lost_flag,
 								  encoded_data,
 								  encoded_data_len,
 								  target,
@@ -345,6 +366,8 @@ static switch_status_t switch_silk_decode(switch_codec_t *codec,
 		if (ret){
 			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "SKP_Silk_Decode returned %d!\n", ret);
 			printSilkError(ret);
+			/* if FEC was activated, we can ignore bit errors*/
+			if (! (ret == SKP_SILK_DEC_PAYLOAD_ERROR && did_lbrr))
 			return SWITCH_STATUS_FALSE;
 		}