Add sender controlled playout delay limits

webrtc/modules/video_coding/timing.h

Index: webrtc/modules/video_coding/timing.h
diff --git a/webrtc/modules/video_coding/timing.h b/webrtc/modules/video_coding/timing.h
index e593c9acbc35a7a1c3973d36a0274c161e880a84..409e0d817c62d63640e5a736f42e68f66f21abb6 100644
--- a/webrtc/modules/video_coding/timing.h
+++ b/webrtc/modules/video_coding/timing.h
@@ -41,8 +41,17 @@ class VCMTiming {
   // get the desired jitter buffer level.
   void SetJitterDelay(uint32_t required_delay_ms);
 
-  // Set the minimum playout delay required to sync video with audio.
-  void set_min_playout_delay(uint32_t min_playout_delay);
+  // Set the minimum playout delay from capture to render in ms.
+  void set_min_playout_delay(uint32_t min_playout_delay_ms);
+
+  // Returns the minimum playout delay from capture to render in ms.
+  uint32_t min_playout_delay();
+
+  // Set the maximum playout delay from capture to render in ms.
+  void set_max_playout_delay(uint32_t max_playout_delay_ms);
+
+  // Returns the maximum playout delay from capture to render in ms.
+  uint32_t max_playout_delay();
 
   // Increases or decreases the current delay to get closer to the target delay.
   // Calculates how long it has been since the previous call to this function,
@@ -111,7 +120,13 @@ class VCMTiming {
   TimestampExtrapolator* ts_extrapolator_ GUARDED_BY(crit_sect_);
   std::unique_ptr<VCMCodecTimer> codec_timer_ GUARDED_BY(crit_sect_);
   uint32_t render_delay_ms_ GUARDED_BY(crit_sect_);
+  // Best-effort playout delay range for frames from capture to render.
+  // The receiver tries to keep the delay between |min_playout_delay_ms_|
+  // and |max_playout_delay_ms_| taking the network jitter into account.
+  // A special case is where min_playout_delay_ms_ = max_playout_delay_ms_ = 0,
+  // in which case the receiver tries to play the frames as they arrive.
   uint32_t min_playout_delay_ms_ GUARDED_BY(crit_sect_);
+  uint32_t max_playout_delay_ms_ GUARDED_BY(crit_sect_);
   uint32_t jitter_delay_ms_ GUARDED_BY(crit_sect_);
   uint32_t current_delay_ms_ GUARDED_BY(crit_sect_);
   int last_decode_ms_ GUARDED_BY(crit_sect_);