From: Mike Brady <mikebrady@eircom.net>
Date: Sat, 10 Feb 2018 17:43:47 +0000 (+0000)
Subject: Only request a resend one time, after about a second. Stop making resend requests... 
X-Git-Tag: 3.2d29~72
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f94d6a5d163ebf53fcdb3ca9339a7326c1288bbb;p=thirdparty%2Fshairport-sync.git

Only request a resend one time, after about a second. Stop making resend requests if there is a send-to error for 10 seconds.
---

diff --git a/player.c b/player.c
index fb617770..1c746210 100644
--- a/player.c
+++ b/player.c
@@ -142,7 +142,6 @@ int64_t monotonic_timestamp(uint32_t timestamp, rtsp_conn_info *conn) {
         conn->timestamp_epoch--;
     }
   }
-  conn->last_timestamp = timestamp;
   return_value = conn->timestamp_epoch;
   return_value <<= 32;
   return_value += timestamp;
@@ -155,6 +154,7 @@ int64_t monotonic_timestamp(uint32_t timestamp, rtsp_conn_info *conn) {
   }
   if (return_value < 0)
     debug(1, "monotonic rtptime is negative!");
+  conn->last_timestamp = timestamp;
   return return_value;
 }
 
@@ -870,8 +870,8 @@ static abuf_t *buffer_get_frame(rtsp_conn_info *conn) {
               if (local_time_now >= conn->first_packet_time_to_play) {
                 debug(
                     1,
-                    "First packet is late! It should have played before now. Flushing 0.1 seconds");
-                player_flush(conn->first_packet_timestamp + 4410 * conn->output_sample_ratio, conn);
+                    "First packet is late! It should have played before now. Flushing 0.5 seconds");
+                player_flush(conn->first_packet_timestamp + 5 * 4410 * conn->output_sample_ratio, conn);
               }
             }
           }
@@ -1155,7 +1155,11 @@ static abuf_t *buffer_get_frame(rtsp_conn_info *conn) {
   // packets have arrived... last-chance resend
 
   if (!conn->ab_buffering) {
-    for (i = 64; i < (seq_diff(conn->ab_read, conn->ab_write, conn->ab_read) / 2); i = (i * 2)) {
+    // check at half second intervals
+ //   for (i = 500000/7982 ; i < (seq_diff(conn->ab_read, conn->ab_write, conn->ab_read)); i += 500000/7982) {
+    // check once, after a second has elapsed, assuming 352 frames per packet
+      i = 44100/352;
+      if (i<seq_diff(conn->ab_read, conn->ab_write, conn->ab_read)) {
       seq_t next = seq_sum(conn->ab_read, i);
       abuf = conn->audio_buffer + BUFIDX(next);
       if (!abuf->ready) {
@@ -1420,7 +1424,7 @@ static void *player_thread_func(void *arg) {
 
   conn->timestamp_epoch = 0; // indicate that the next timestamp will be the first one.
   conn->maximum_timestamp_interval =
-      conn->input_rate * 60; // actually there shouldn't be more than about 13v
+      conn->input_rate * 60; // actually there shouldn't be more than about 13 
                              // seconds of a gap between successive rtptimes, at
                              // worst
 
@@ -1429,7 +1433,7 @@ static void *player_thread_func(void *arg) {
   //  debug(1, "Output sample ratio is %d.", conn->output_sample_ratio);
 
   conn->max_frame_size_change =
-      500 * conn->output_sample_ratio; // we add or subtract one frame at the nominal
+      1 * conn->output_sample_ratio; // we add or subtract one frame at the nominal
                                        // rate, multiply it by the frame ratio.
                                        // but, on some occasions, more than one frame could be added
 
diff --git a/player.h b/player.h
index dad0ed18..fc3dfd8e 100644
--- a/player.h
+++ b/player.h
@@ -129,6 +129,8 @@ typedef struct {
   // RTP stuff
   // only one RTP session can be active at a time.
   int rtp_running;
+  uint64_t rtp_time_of_last_resend_request_error_fp;
+
 
   char client_ip_string[INET6_ADDRSTRLEN]; // the ip string pointing to the client
   char self_ip_string[INET6_ADDRSTRLEN];   // the ip string being used by this program -- it
diff --git a/rtp.c b/rtp.c
index 43a6d3b0..2cc8f111 100644
--- a/rtp.c
+++ b/rtp.c
@@ -46,7 +46,7 @@
 void memory_barrier();
 
 void rtp_initialise(rtsp_conn_info *conn) {
-
+  conn->rtp_time_of_last_resend_request_error_fp = 0;
   conn->rtp_running = 0;
   // initialise the timer mutex
   int rc = pthread_mutex_init(&conn->reference_time_mutex, NULL);
@@ -131,7 +131,7 @@ void *rtp_audio_receiver(void *arg) {
         pktp += 4;
         plen -= 4;
       }
-      seq_t seqno = ntohs(*(unsigned short *)(pktp + 2));
+      seq_t seqno = ntohs(*(uint16_t *)(pktp + 2));
       // increment last_seqno and see if it's the same as the incoming seqno
 
       if (last_seqno == -1)
@@ -142,7 +142,7 @@ void *rtp_audio_receiver(void *arg) {
         //  debug(3, "RTP: Packets out of sequence: expected: %d, got %d.", last_seqno, seqno);
         last_seqno = seqno; // reset warning...
       }
-      int64_t timestamp = monotonic_timestamp(ntohl(*(unsigned long *)(pktp + 4)), conn);
+      int64_t timestamp = monotonic_timestamp(ntohl(*(uint32_t*)(pktp + 4)), conn);
 
       // if (packet[1]&0x10)
       //	debug(1,"Audio packet Extension bit set.");
@@ -224,6 +224,8 @@ void *rtp_control_receiver(void *arg) {
         // debug(1,"Remote Sync Time: %0llx.",remote_time_of_sync);
 
         sync_rtp_timestamp = monotonic_timestamp(ntohl(*((uint32_t *)&packet[16])), conn);
+        
+        debug(1,"Sync timestamp is %u.",ntohl(*((uint32_t *)&packet[16])));
 
         if (config.userSuppliedLatency) {
           if (config.userSuppliedLatency != conn->latency) {
@@ -232,6 +234,7 @@ void *rtp_control_receiver(void *arg) {
           conn->latency = config.userSuppliedLatency;
         } else if (packet[0] &
                    0x10) { // only set latency if it's a packet just after a flush or resume
+          debug(1,"Set latency");
           int64_t rtp_timestamp_less_latency =
               monotonic_timestamp(ntohl(*((uint32_t *)&packet[4])), conn);
           int64_t la = sync_rtp_timestamp - rtp_timestamp_less_latency + config.fixedLatencyOffset;
@@ -277,12 +280,12 @@ void *rtp_control_receiver(void *arg) {
         debug(1, "Sync packet received before we got a timing packet back.");
       }
     } else if (packet[1] == 0xd6) { // resent audio data in the control path -- whaale only?
-      // debug(1, "Control Port -- Retransmitted Audio Data Packet received.");
+      debug(1, "Control Port -- Retransmitted Audio Data Packet received.");
       pktp = packet + 4;
       plen -= 4;
-      seq_t seqno = ntohs(*(unsigned short *)(pktp + 2));
+      seq_t seqno = ntohs(*(uint16_t*)(pktp + 2));
 
-      int64_t timestamp = monotonic_timestamp(ntohl(*(unsigned long *)(pktp + 4)), conn);
+      int64_t timestamp = monotonic_timestamp(ntohl(*(uint32_t*)(pktp + 4)), conn);
 
       pktp += 12;
       plen -= 12;
@@ -446,9 +449,12 @@ void *rtp_timing_receiver(void *arg) {
       return_time = arrival_time - conn->departure_time;
 
       uint64_t rtus = (return_time * 1000000) >> 32;
+      
 
       if (rtus < 300000) {
 
+        // debug(2,"Synchronisation ping return time is %f milliseconds.",(rtus*1.0)/1000);
+
         // distant_receive_time =
         // ((uint64_t)ntohl(*((uint32_t*)&packet[16])))<<32+ntohl(*((uint32_t*)&packet[20]));
 
@@ -829,11 +835,18 @@ void rtp_request_resend(seq_t first, uint32_t count, rtsp_conn_info *conn) {
       msgsize = sizeof(struct sockaddr_in6);
     }
 #endif
-    if (sendto(conn->audio_socket, req, sizeof(req), 0,
-               (struct sockaddr *)&conn->rtp_client_control_socket, msgsize) == -1) {
-      char em[1024];
-      strerror_r(errno, em, sizeof(em));
-      debug(1, "Error %d using send-to to an audio socket: \"%s\".", errno, em);
+    uint64_t time_of_sending_fp = get_absolute_time_in_fp();
+    uint64_t resend_error_backoff_time = (uint64_t)10<<32; // ten seconds
+    if ((conn->rtp_time_of_last_resend_request_error_fp) || ((time_of_sending_fp-conn->rtp_time_of_last_resend_request_error_fp)>resend_error_backoff_time)) {
+      if (sendto(conn->audio_socket, req, sizeof(req), 0,
+                 (struct sockaddr *)&conn->rtp_client_control_socket, msgsize) == -1) {
+        char em[1024];
+        strerror_r(errno, em, sizeof(em));
+        debug(1, "Error %d using send-to to an audio socket: \"%s\". ", errno, em);
+        conn->rtp_time_of_last_resend_request_error_fp = time_of_sending_fp;
+      } else {
+        conn->rtp_time_of_last_resend_request_error_fp=0;
+      }
     }
   } else {
     // if (!request_sent) {