media/cast/sender/video_sender.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef MEDIA_CAST_SENDER_VIDEO_SENDER_H_
   6 #define MEDIA_CAST_SENDER_VIDEO_SENDER_H_
   7
   8 #include "base/callback.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/memory/weak_ptr.h"
  12 #include "base/threading/non_thread_safe.h"
  13 #include "base/time/tick_clock.h"
  14 #include "base/time/time.h"
  15 #include "media/cast/cast_config.h"
  16 #include "media/cast/sender/congestion_control.h"
  17 #include "media/cast/sender/frame_sender.h"
  18
  19 namespace media {
  20
  21 class VideoFrame;
  22
  23 namespace cast {
  24
  25 class CastTransportSender;
  26 class VideoEncoder;
  27 class VideoFrameFactory;
  28
  29 typedef base::Callback<void(base::TimeDelta)> PlayoutDelayChangeCB;
  30
  31 // Not thread safe. Only called from the main cast thread.
  32 // This class owns all objects related to sending video, objects that create RTP
  33 // packets, congestion control, video encoder, parsing and sending of
  34 // RTCP packets.
  35 // Additionally it posts a bunch of delayed tasks to the main thread for various
  36 // timeouts.
  37 class VideoSender : public FrameSender,
  38                     public base::NonThreadSafe,
  39                     public base::SupportsWeakPtr<VideoSender> {
  40  public:
  41   VideoSender(scoped_refptr<CastEnvironment> cast_environment,
  42               const VideoSenderConfig& video_config,
  43               const StatusChangeCallback& status_change_cb,
  44               const CreateVideoEncodeAcceleratorCallback& create_vea_cb,
  45               const CreateVideoEncodeMemoryCallback& create_video_encode_mem_cb,
  46               CastTransportSender* const transport_sender,
  47               const PlayoutDelayChangeCB& playout_delay_change_cb);
  48
  49   ~VideoSender() override;
  50
  51   // Note: It is not guaranteed that |video_frame| will actually be encoded and
  52   // sent, if VideoSender detects too many frames in flight.  Therefore, clients
  53   // should be careful about the rate at which this method is called.
  54   void InsertRawVideoFrame(const scoped_refptr<media::VideoFrame>& video_frame,
  55                            const base::TimeTicks& reference_time);
  56
  57   // Creates a |VideoFrameFactory| object to vend |VideoFrame| object with
  58   // encoder affinity (defined as offering some sort of performance benefit). If
  59   // the encoder does not have any such capability, returns null.
  60   scoped_ptr<VideoFrameFactory> CreateVideoFrameFactory();
  61
  62  protected:
  63   int GetNumberOfFramesInEncoder() const final;
  64   base::TimeDelta GetInFlightMediaDuration() const final;
  65   void OnAck(uint32 frame_id) final;
  66
  67   // Return the maximum target bitrate that should be used for the given video
  68   // |frame|.  This will be provided to CongestionControl as a soft maximum
  69   // limit, and should be interpreted as "the point above which the extra
  70   // encoder CPU time + network bandwidth usage isn't warranted for the amount
  71   // of further quality improvement to be gained."
  72   static int GetMaximumTargetBitrateForFrame(const media::VideoFrame& frame);
  73
  74  private:
  75   // Called by the |video_encoder_| with the next EncodedFrame to send.
  76   void OnEncodedVideoFrame(const scoped_refptr<media::VideoFrame>& video_frame,
  77                            int encoder_bitrate,
  78                            scoped_ptr<SenderEncodedFrame> encoded_frame);
  79
  80   // Encodes media::VideoFrame images into EncodedFrames.  Per configuration,
  81   // this will point to either the internal software-based encoder or a proxy to
  82   // a hardware-based encoder.
  83   scoped_ptr<VideoEncoder> video_encoder_;
  84
  85   // The number of frames queued for encoding, but not yet sent.
  86   int frames_in_encoder_;
  87
  88   // The duration of video queued for encoding, but not yet sent.
  89   base::TimeDelta duration_in_encoder_;
  90
  91   // The timestamp of the frame that was last enqueued in |video_encoder_|.
  92   RtpTimestamp last_enqueued_frame_rtp_timestamp_;
  93   base::TimeTicks last_enqueued_frame_reference_time_;
  94
  95   // Remember what we set the bitrate to before, no need to set it again if
  96   // we get the same value.
  97   int last_bitrate_;
  98
  99   PlayoutDelayChangeCB playout_delay_change_cb_;
 100
 101   // The video encoder's performance metrics as of the last call to
 102   // OnEncodedVideoFrame().  See header file comments for SenderEncodedFrame for
 103   // an explanation of these values.
 104   double last_reported_deadline_utilization_;
 105   double last_reported_lossy_utilization_;
 106
 107   // NOTE: Weak pointers must be invalidated before all other member variables.
 108   base::WeakPtrFactory<VideoSender> weak_factory_;
 109
 110   DISALLOW_COPY_AND_ASSIGN(VideoSender);
 111 };
 112
 113 }  // namespace cast
 114 }  // namespace media
 115
 116 #endif  // MEDIA_CAST_SENDER_VIDEO_SENDER_H_