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      1 /*
      2  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
      3  *
      4  *  Use of this source code is governed by a BSD-style license
      5  *  that can be found in the LICENSE file in the root of the source
      6  *  tree. An additional intellectual property rights grant can be found
      7  *  in the file PATENTS.  All contributing project authors may
      8  *  be found in the AUTHORS file in the root of the source tree.
      9  */
     10 
     11 #ifndef WEBRTC_MODULES_VIDEO_CODING_MAIN_SOURCE_MEDIA_OPTIMIZATION_H_
     12 #define WEBRTC_MODULES_VIDEO_CODING_MAIN_SOURCE_MEDIA_OPTIMIZATION_H_
     13 
     14 #include <list>
     15 
     16 #include "webrtc/modules/interface/module_common_types.h"
     17 #include "webrtc/modules/video_coding/main/interface/video_coding.h"
     18 #include "webrtc/modules/video_coding/main/source/media_opt_util.h"
     19 #include "webrtc/modules/video_coding/main/source/qm_select.h"
     20 #include "webrtc/system_wrappers/interface/scoped_ptr.h"
     21 
     22 namespace webrtc {
     23 
     24 // Forward declarations.
     25 class Clock;
     26 class FrameDropper;
     27 class VCMContentMetricsProcessing;
     28 
     29 namespace media_optimization {
     30 
     31 // TODO(andresp): Make thread safe.
     32 class MediaOptimization {
     33  public:
     34   explicit MediaOptimization(Clock* clock);
     35   ~MediaOptimization();
     36 
     37   // TODO(andresp): Can Reset and SetEncodingData be done at construction time
     38   // only?
     39   void Reset();
     40 
     41   // Informs media optimization of initial encoding state.
     42   void SetEncodingData(VideoCodecType send_codec_type,
     43                        int32_t max_bit_rate,
     44                        uint32_t frame_rate,
     45                        uint32_t bit_rate,
     46                        uint16_t width,
     47                        uint16_t height,
     48                        int num_temporal_layers,
     49                        int32_t mtu);
     50 
     51   // Sets target rates for the encoder given the channel parameters.
     52   // Inputs:  target bitrate - the encoder target bitrate in bits/s.
     53   //          fraction_lost - packet loss rate in % in the network.
     54   //          round_trip_time_ms - round trip time in milliseconds.
     55   //          min_bit_rate - the bit rate of the end-point with lowest rate.
     56   //          max_bit_rate - the bit rate of the end-point with highest rate.
     57   // TODO(andresp): Find if the callbacks can be triggered only after releasing
     58   // an internal critical section.
     59   uint32_t SetTargetRates(uint32_t target_bitrate,
     60                           uint8_t fraction_lost,
     61                           uint32_t round_trip_time_ms,
     62                           VCMProtectionCallback* protection_callback,
     63                           VCMQMSettingsCallback* qmsettings_callback);
     64 
     65   void EnableProtectionMethod(bool enable, VCMProtectionMethodEnum method);
     66   void EnableQM(bool enable);
     67   void EnableFrameDropper(bool enable);
     68 
     69   // Lets the sender suspend video when the rate drops below
     70   // |threshold_bps|, and turns back on when the rate goes back up above
     71   // |threshold_bps| + |window_bps|.
     72   void SuspendBelowMinBitrate(int threshold_bps, int window_bps);
     73   bool IsVideoSuspended() const;
     74 
     75   bool DropFrame();
     76 
     77   void UpdateContentData(const VideoContentMetrics* content_metrics);
     78 
     79   // Informs Media Optimization of encoding output: Length and frame type.
     80   int32_t UpdateWithEncodedData(int encoded_length,
     81                                 uint32_t timestamp,
     82                                 FrameType encoded_frame_type);
     83 
     84   uint32_t InputFrameRate();
     85   uint32_t SentFrameRate();
     86   uint32_t SentBitRate();
     87   VCMFrameCount SentFrameCount();
     88 
     89  private:
     90   enum {
     91     kFrameCountHistorySize = 90
     92   };
     93   enum {
     94     kFrameHistoryWinMs = 2000
     95   };
     96   enum {
     97     kBitrateAverageWinMs = 1000
     98   };
     99 
    100   struct EncodedFrameSample;
    101   typedef std::list<EncodedFrameSample> FrameSampleList;
    102 
    103   void UpdateIncomingFrameRate();
    104   void PurgeOldFrameSamples(int64_t now_ms);
    105   void UpdateSentBitrate(int64_t now_ms);
    106   void UpdateSentFramerate();
    107 
    108   // Computes new Quality Mode.
    109   int32_t SelectQuality(VCMQMSettingsCallback* qmsettings_callback);
    110 
    111   // Verifies if QM settings differ from default, i.e. if an update is required.
    112   // Computes actual values, as will be sent to the encoder.
    113   bool QMUpdate(VCMResolutionScale* qm,
    114                 VCMQMSettingsCallback* qmsettings_callback);
    115 
    116   // Checks if we should make a QM change. Return true if yes, false otherwise.
    117   bool CheckStatusForQMchange();
    118 
    119   void ProcessIncomingFrameRate(int64_t now);
    120 
    121   // Checks conditions for suspending the video. The method compares
    122   // |target_bit_rate_| with the threshold values for suspension, and changes
    123   // the state of |video_suspended_| accordingly.
    124   void CheckSuspendConditions();
    125 
    126   Clock* clock_;
    127   int32_t max_bit_rate_;
    128   VideoCodecType send_codec_type_;
    129   uint16_t codec_width_;
    130   uint16_t codec_height_;
    131   float user_frame_rate_;
    132   scoped_ptr<FrameDropper> frame_dropper_;
    133   scoped_ptr<VCMLossProtectionLogic> loss_prot_logic_;
    134   uint8_t fraction_lost_;
    135   uint32_t send_statistics_[4];
    136   uint32_t send_statistics_zero_encode_;
    137   int32_t max_payload_size_;
    138   int target_bit_rate_;
    139   float incoming_frame_rate_;
    140   int64_t incoming_frame_times_[kFrameCountHistorySize];
    141   bool enable_qm_;
    142   std::list<EncodedFrameSample> encoded_frame_samples_;
    143   uint32_t avg_sent_bit_rate_bps_;
    144   uint32_t avg_sent_framerate_;
    145   uint32_t key_frame_cnt_;
    146   uint32_t delta_frame_cnt_;
    147   scoped_ptr<VCMContentMetricsProcessing> content_;
    148   scoped_ptr<VCMQmResolution> qm_resolution_;
    149   int64_t last_qm_update_time_;
    150   int64_t last_change_time_;  // Content/user triggered.
    151   int num_layers_;
    152   bool suspension_enabled_;
    153   bool video_suspended_;
    154   int suspension_threshold_bps_;
    155   int suspension_window_bps_;
    156 };
    157 }  // namespace media_optimization
    158 }  // namespace webrtc
    159 
    160 #endif  // WEBRTC_MODULES_VIDEO_CODING_MAIN_SOURCE_MEDIA_OPTIMIZATION_H_
    161