[vlc-devel] [PATCH v3 2/6] clock: add vlc_clock_main_SetInputDrift

[Thomas Guillem]

---
 src/clock/clock.c | 15 +++++++++++++--
 src/clock/clock.h |  8 ++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/src/clock/clock.c b/src/clock/clock.c
index cfbb5eb6f6d..0bb2a9fe375 100644
--- a/src/clock/clock.c
+++ b/src/clock/clock.c
@@ -45,6 +45,7 @@ struct vlc_clock_main_t
     average_t coeff_avg; /* Moving average to smooth out the instant coeff */
     double rate;
     double coeff;
+    vlc_tick_t input_drift;
     vlc_tick_t offset;
     vlc_tick_t delay;
 
@@ -88,6 +89,7 @@ static vlc_tick_t main_stream_to_system(vlc_clock_main_t *main_clock,
 static void vlc_clock_main_reset(vlc_clock_main_t *main_clock)
 {
     AvgReset(&main_clock->coeff_avg);
+    main_clock->input_drift = 0;
     main_clock->coeff = 1.0f;
     main_clock->rate = 1.0f;
     main_clock->offset = VLC_TICK_INVALID;
@@ -266,7 +268,8 @@ static vlc_tick_t vlc_clock_slave_to_system_locked(vlc_clock_t *clock,
         system = vlc_clock_monotonic_to_system_locked(clock, now, ts, rate);
     }
 
-    return system + (clock->delay - main_clock->delay) * rate;
+    return system + main_clock->input_drift +
+        (clock->delay - main_clock->delay) * rate;
 }
 
 static vlc_tick_t vlc_clock_master_to_system_locked(vlc_clock_t *clock,
@@ -282,7 +285,7 @@ static vlc_tick_t vlc_clock_master_to_system_locked(vlc_clock_t *clock,
         system = vlc_clock_monotonic_to_system_locked(clock, now, ts, rate);
     }
 
-    return system + clock->delay * rate;
+    return system + main_clock->input_drift + clock->delay * rate;
 }
 
 static vlc_tick_t vlc_clock_slave_update(vlc_clock_t *clock,
@@ -370,6 +373,7 @@ vlc_clock_main_t *vlc_clock_main_New(void)
     main_clock->master = NULL;
     main_clock->rc = 1;
 
+    main_clock->input_drift = 0;
     main_clock->coeff = 1.0f;
     main_clock->rate = 1.0f;
     main_clock->offset = VLC_TICK_INVALID;
@@ -439,6 +443,13 @@ void vlc_clock_main_SetDejitter(vlc_clock_main_t *main_clock,
     vlc_mutex_unlock(&main_clock->lock);
 }
 
+void vlc_clock_main_SetInputDrift(vlc_clock_main_t *main_clock, double drift)
+{
+    vlc_mutex_lock(&main_clock->lock);
+    main_clock->input_drift = drift;
+    vlc_mutex_unlock(&main_clock->lock);
+}
+
 void vlc_clock_main_ChangePause(vlc_clock_main_t *main_clock, vlc_tick_t now,
                                 bool paused)
 {
diff --git a/src/clock/clock.h b/src/clock/clock.h
index f780d448bcc..f628024e057 100644
--- a/src/clock/clock.h
+++ b/src/clock/clock.h
@@ -90,6 +90,14 @@ void vlc_clock_main_SetFirstPcr(vlc_clock_main_t *main_clock,
 void vlc_clock_main_SetInputDejitter(vlc_clock_main_t *main_clock,
                                      vlc_tick_t delay);
 
+/**
+ * Set the input drift
+ *
+ * Set the average drift calculted by the input_clock, it is used to delay all
+ * output clocks according to this drift.
+ **/
+void vlc_clock_main_SetInputDrift(vlc_clock_main_t *main_clock, double drift);
+
 /**
  * This function sets the dejitter delay to absorb the clock jitter
  *
-- 
2.30.0