display the number of samples used to calculcate drift, clean up the settings for...

diff --git a/player.c b/player.c
index 595c1fdabe277fcd255dbb36daf8b3b800cb22e5..f2e1a7fdc1eff2c0bebc2a2ab23142df74c88160 100644 (file)
--- a/player.c
+++ b/player.c
@@ -2416,7 +2416,8 @@ void *player_thread_func(void *arg) {
                          "%*d,"   /* max buffer occupancy */
                          "%*.2f," /* input frame rate */
                          "%*.2f," /* output frame rate */
-                         "%*.2f", /* client clock to local clock drift in ppm */
+                         "%*.2f," /* output frame rate */
+                         "%*d",   /* sample count */
                          10,
                          1000 * moving_average_sync_error / config.output_rate, 10,
                          moving_average_correction * 1000000 / (352 * conn->output_sample_ratio),
@@ -2425,7 +2426,7 @@ void *player_thread_func(void *arg) {
                          12, play_number, 7, conn->missing_packets, 7, conn->late_packets, 7,
                          conn->too_late_packets, 7, conn->resend_requests, 7,
                          minimum_dac_queue_size, 5, minimum_buffer_occupancy, 5,
-                         maximum_buffer_occupancy, 11, conn->input_frame_rate, 11, conn->frame_rate ,  10, (1.0-conn->local_to_remote_time_gradient)*1000000);
+                         maximum_buffer_occupancy, 11, conn->input_frame_rate, 11, conn->frame_rate ,  10, (1.0-conn->local_to_remote_time_gradient)*1000000, 6, conn->local_to_remote_time_gradient_sample_count);
                 } else {
                   inform("%*.2f," /* Sync error in milliseconds */
                          "%*d,"   /* total packets */

diff --git a/player.h b/player.h
index 5402a18f8c67fda977990c290c1985b3fdc41507..a7d961a580cc01ea4000748394928d8ad9ca273d 100644 (file)
--- a/player.h
+++ b/player.h
@@ -24,7 +24,7 @@
 #include "alac.h"
 #include "audio.h"
 
-#define time_ping_history 32
+#define time_ping_history 64  // at 1 per three seconds, approximately three minutes of records
 
 typedef struct time_ping_record {
   uint64_t local_to_remote_difference;
@@ -207,6 +207,7 @@ typedef struct {
   pthread_mutex_t reference_time_mutex;
 
   double local_to_remote_time_gradient; // if no drift, this would be exactly 1.0; likely it's slightly above or  below.
+  int local_to_remote_time_gradient_sample_count; // the number of samples used to calculate the gradient
   uint64_t local_to_remote_time_difference; // used to switch between local and remote clocks
   uint64_t local_to_remote_time_difference_measurement_time; // when the above was calculated
 

diff --git a/rtp.c b/rtp.c
index df71f41313554fb751866e3af2139c8793073f59..96bb0fcf8bd0f0a109a8207ad7dc4eb111460ffd 100644 (file)
--- a/rtp.c
+++ b/rtp.c
@@ -702,9 +702,12 @@ void *rtp_timing_receiver(void *arg) {
             uint64_t x_bar = 0; // local timestamp average
             int sample_count = 0;
           
-            
+            // approximate time in seconds to let the system settle down
+            const int settling_time = 60;
+            // number of points to have for calculating a valid drift
+            const int sample_point_minimum = 8;
             for (cc = 0; cc < conn->time_ping_count; cc++) 
-              if ((conn->time_pings[cc].chosen) && (conn->time_pings[cc].sequence_number>9)) { // wait for a minute or so....
+              if ((conn->time_pings[cc].chosen) && (conn->time_pings[cc].sequence_number>(settling_time/3))) { // wait for a approximate settling time
                 y_bar += (conn->time_pings[cc].remote_time>>12); //precision is down to 1/4th of a microsecond
                 x_bar += (conn->time_pings[cc].local_time>>12);
                 sample_count++;
@@ -717,7 +720,7 @@ void *rtp_timing_receiver(void *arg) {
             int64_t mtl, mbl;
             mtl=0;mbl=0;
             for (cc = 0; cc < conn->time_ping_count; cc++)
-              if ((conn->time_pings[cc].chosen) && (conn->time_pings[cc].sequence_number>9)) {
+              if ((conn->time_pings[cc].chosen) && (conn->time_pings[cc].sequence_number>(settling_time/3))) {
             
                 uint64_t slt = conn->time_pings[cc].local_time>>12;
                 if (slt > x_bar)
@@ -734,8 +737,9 @@ void *rtp_timing_receiver(void *arg) {
                 mtl = mtl + xid*yid;
                 mbl = mbl + xid*xid;              
               } 
-            if (sample_count > 2) { 
-              conn->local_to_remote_time_gradient = (1.0*mtl)/mbl;  
+            conn->local_to_remote_time_gradient_sample_count = sample_count; 
+            if (sample_count > sample_point_minimum) { 
+              conn->local_to_remote_time_gradient = (1.0*mtl)/mbl;
               // debug(1,"Drift is %12.2f ppm, based on %d samples.",(1.0-conn->local_to_remote_time_gradient)*1000000,sample_count);
             } else {
               conn->local_to_remote_time_gradient = 1.0;  
@@ -971,13 +975,16 @@ int have_timestamp_timing_information(rtsp_conn_info *conn) {
     return 1;
 }
 
+// set this to zero to use the rates supplied by the sources, which might not always be completely right...
+const int use_nominal_rate = 1; // specify whether to use the nominal input rate, usually 44100 fps 
+
 int sanitised_source_rate_information(int64_t *frames, uint64_t *time, rtsp_conn_info *conn) {
   int result = 0;
-  *frames = conn->input_rate;
+  *frames = conn->input_rate; 
   *time = (uint64_t)(0x100000000); // one second in fp form
   int64_t local_frames = conn->reference_to_previous_frame_difference;
   uint64_t local_time = conn->reference_to_previous_time_difference;
-  if ((local_frames == 0) || (local_time == 0)) {
+  if ((local_frames == 0) || (local_time == 0) || (use_nominal_rate)) {
     result = 1;
   } else {
     double calculated_frame_rate = ((1.0*local_frames)/local_time)*(uint64_t)0x100000000;