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// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef MEDIA_CAST_SENDER_VIDEO_SENDER_H_
#define MEDIA_CAST_SENDER_VIDEO_SENDER_H_
#include <memory>
#include "base/callback.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/memory/weak_ptr.h"
#include "base/time/tick_clock.h"
#include "base/time/time.h"
#include "media/capture/video/video_capture_feedback.h"
#include "media/cast/cast_config.h"
#include "media/cast/cast_sender.h"
#include "media/cast/common/rtp_time.h"
#include "media/cast/sender/congestion_control.h"
#include "media/cast/sender/frame_sender.h"
namespace media {
class VideoFrame;
namespace cast {
class CastTransport;
class VideoEncoder;
class VideoFrameFactory;
using PlayoutDelayChangeCB = base::RepeatingCallback<void(base::TimeDelta)>;
// Not thread safe. Only called from the main cast thread.
// This class owns all objects related to sending video, objects that create RTP
// packets, congestion control, video encoder, parsing and sending of
// RTCP packets.
// Additionally it posts a bunch of delayed tasks to the main thread for various
// timeouts.
class VideoSender : public FrameSender {
public:
VideoSender(scoped_refptr<CastEnvironment> cast_environment,
const FrameSenderConfig& video_config,
StatusChangeCallback status_change_cb,
const CreateVideoEncodeAcceleratorCallback& create_vea_cb,
CastTransport* const transport_sender,
PlayoutDelayChangeCB playout_delay_change_cb,
media::VideoCaptureFeedbackCB feedback_callback);
VideoSender(const VideoSender&) = delete;
VideoSender& operator=(const VideoSender&) = delete;
~VideoSender() override;
// Note: It is not guaranteed that |video_frame| will actually be encoded and
// sent, if VideoSender detects too many frames in flight. Therefore, clients
// should be careful about the rate at which this method is called.
void InsertRawVideoFrame(scoped_refptr<media::VideoFrame> video_frame,
const base::TimeTicks& reference_time);
// Creates a |VideoFrameFactory| object to vend |VideoFrame| object with
// encoder affinity (defined as offering some sort of performance benefit). If
// the encoder does not have any such capability, returns null.
std::unique_ptr<VideoFrameFactory> CreateVideoFrameFactory();
base::WeakPtr<VideoSender> AsWeakPtr();
protected:
int GetNumberOfFramesInEncoder() const final;
base::TimeDelta GetInFlightMediaDuration() const final;
private:
// Called by the |video_encoder_| with the next EncodedFrame to send.
void OnEncodedVideoFrame(scoped_refptr<media::VideoFrame> video_frame,
int encoder_bitrate,
std::unique_ptr<SenderEncodedFrame> encoded_frame);
// Encodes media::VideoFrame images into EncodedFrames. Per configuration,
// this will point to either the internal software-based encoder or a proxy to
// a hardware-based encoder.
std::unique_ptr<VideoEncoder> video_encoder_;
// The number of frames queued for encoding, but not yet sent.
int frames_in_encoder_;
// The duration of video queued for encoding, but not yet sent.
base::TimeDelta duration_in_encoder_;
// The timestamp of the frame that was last enqueued in |video_encoder_|.
RtpTimeTicks last_enqueued_frame_rtp_timestamp_;
base::TimeTicks last_enqueued_frame_reference_time_;
// Remember what we set the bitrate to before, no need to set it again if
// we get the same value.
int last_bitrate_;
PlayoutDelayChangeCB playout_delay_change_cb_;
media::VideoCaptureFeedbackCB feedback_cb_;
// Indicates we are operating in a mode where the target playout latency is
// low for best user experience. When operating in low latency mode, we
// prefer dropping frames over increasing target playout time.
bool low_latency_mode_;
// The video encoder's performance metrics as of the last call to
// OnEncodedVideoFrame(). See header file comments for SenderEncodedFrame for
// an explanation of these values.
double last_reported_encoder_utilization_;
double last_reported_lossy_utilization_;
// This tracks the time when the request was sent to encoder to encode a key
// frame on receiving a Pli message. It is used to limit the sender not
// to duplicately respond to multiple Pli messages in a short period.
base::TimeTicks last_time_attempted_to_resolve_pli_;
// NOTE: Weak pointers must be invalidated before all other member variables.
base::WeakPtrFactory<VideoSender> weak_factory_{this};
};
} // namespace cast
} // namespace media
#endif // MEDIA_CAST_SENDER_VIDEO_SENDER_H_
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