Add sender controlled playout delay limits

webrtc/modules/video_coding/timing.h

 /*
  *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 17 matching lines @@
   // The primary timing component should be passed
   // if this is the dual timing component.
   explicit VCMTiming(Clock* clock, VCMTiming* master_timing = NULL);
   virtual ~VCMTiming();
 
   // Resets the timing to the initial state.
   void Reset();
   void ResetDecodeTime();
 
   // Set the amount of time needed to render an image. Defaults to 10 ms.
-  void set_render_delay(uint32_t render_delay_ms);
+  void set_render_delay(int render_delay_ms);
 
   // Set the minimum time the video must be delayed on the receiver to
   // get the desired jitter buffer level.
-  void SetJitterDelay(uint32_t required_delay_ms);
+  void SetJitterDelay(int 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(int min_playout_delay_ms);
+
+  // Returns the minimum playout delay from capture to render in ms.
+  int min_playout_delay();
+
+  // Set the maximum playout delay from capture to render in ms.
+  void set_max_playout_delay(int max_playout_delay_ms);
+
+  // Returns the maximum playout delay from capture to render in ms.
+  int 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,
   // and increases/decreases the delay in proportion to the time difference.
   void UpdateCurrentDelay(uint32_t frame_timestamp);
 
   // Increases or decreases the current delay to get closer to the target delay.
   // Given the actual decode time in ms and the render time in ms for a frame,
   // this function calculates how late the frame is and increases the delay
   // accordingly.
@@ skipping 14 matching lines @@
   // frame_timestamp should be rendered, assuming that the system time currently
   // is now_ms.
   virtual int64_t RenderTimeMs(uint32_t frame_timestamp, int64_t now_ms) const;
 
   // Returns the maximum time in ms that we can wait for a frame to become
   // complete before we must pass it to the decoder.
   virtual uint32_t MaxWaitingTime(int64_t render_time_ms, int64_t now_ms) const;
 
   // Returns the current target delay which is required delay + decode time +
   // render delay.
-  uint32_t TargetVideoDelay() const;
+  int TargetVideoDelay() const;
 
   // Calculates whether or not there is enough time to decode a frame given a
   // certain amount of processing time.
   bool EnoughTimeToDecode(uint32_t available_processing_time_ms) const;
 
   // Return current timing information.
   void GetTimings(int* decode_ms,
                   int* max_decode_ms,
                   int* current_delay_ms,
                   int* target_delay_ms,
                   int* jitter_buffer_ms,
                   int* min_playout_delay_ms,
                   int* render_delay_ms) const;
 
   enum { kDefaultRenderDelayMs = 10 };
   enum { kDelayMaxChangeMsPerS = 100 };
 
  protected:
-  int64_t RequiredDecodeTimeMs() const
-      EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
+  int RequiredDecodeTimeMs() const EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
   int64_t RenderTimeMsInternal(uint32_t frame_timestamp, int64_t now_ms) const
       EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
-  uint32_t TargetDelayInternal() const EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
+  int TargetDelayInternal() const EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
 
  private:
   void UpdateHistograms() const;
 
   CriticalSectionWrapper* crit_sect_;
   Clock* const clock_;
   bool master_ GUARDED_BY(crit_sect_);
   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_);
-  uint32_t min_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 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.
+  int min_playout_delay_ms_ GUARDED_BY(crit_sect_);
+  int max_playout_delay_ms_ GUARDED_BY(crit_sect_);
+  int jitter_delay_ms_ GUARDED_BY(crit_sect_);
+  int current_delay_ms_ GUARDED_BY(crit_sect_);
   int last_decode_ms_ GUARDED_BY(crit_sect_);
   uint32_t prev_frame_timestamp_ GUARDED_BY(crit_sect_);
 
   // Statistics.
   size_t num_decoded_frames_ GUARDED_BY(crit_sect_);
   size_t num_delayed_decoded_frames_ GUARDED_BY(crit_sect_);
   int64_t first_decoded_frame_ms_ GUARDED_BY(crit_sect_);
   uint64_t sum_missed_render_deadline_ms_ GUARDED_BY(crit_sect_);
 };
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_VIDEO_CODING_TIMING_H_