content/renderer/media/webrtc/webrtc_video_track_source.h

// Copyright 2018 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 CONTENT_RENDERER_MEDIA_WEBRTC_WEBRTC_VIDEO_TRACK_SOURCE_H_
#define CONTENT_RENDERER_MEDIA_WEBRTC_WEBRTC_VIDEO_TRACK_SOURCE_H_

#include "base/memory/scoped_refptr.h"
#include "base/threading/thread_checker.h"
#include "content/common/content_export.h"
#include "media/base/video_frame_pool.h"
#include "third_party/webrtc/media/base/adapted_video_track_source.h"
#include "third_party/webrtc/rtc_base/timestamp_aligner.h"

namespace content {

// This class implements webrtc's VideoTrackSourceInterface. To pass frames down
// the webrtc video pipeline, each received a media::VideoFrame is converted to
// a webrtc::VideoFrame, taking any adaptation requested by downstream classes
// into account.
class CONTENT_EXPORT WebRtcVideoTrackSource
    : public rtc::AdaptedVideoTrackSource {
 public:
  struct FrameAdaptationParams {
    bool should_drop_frame;
    int crop_x;
    int crop_y;
    int crop_width;
    int crop_height;
    int scale_to_width;
    int scale_to_height;
  };

  WebRtcVideoTrackSource(bool is_screencast,
                         absl::optional<bool> needs_denoising);
  ~WebRtcVideoTrackSource() override;

  void SetCustomFrameAdaptationParamsForTesting(
      const FrameAdaptationParams& params);

  SourceState state() const override;

  bool remote() const override;
  bool is_screencast() const override;
  absl::optional<bool> needs_denoising() const override;
  void OnFrameCaptured(const scoped_refptr<media::VideoFrame>& frame);

  using webrtc::VideoTrackSourceInterface::AddOrUpdateSink;
  using webrtc::VideoTrackSourceInterface::RemoveSink;

 private:
  FrameAdaptationParams ComputeAdaptationParams(int width,
                                                int height,
                                                int64_t time_us);

  // Delivers |frame| to base class method
  // rtc::AdaptedVideoTrackSource::OnFrame(). If the cropping (given via
  // |frame->visible_rect()|) has changed since the last delivered frame, the
  // whole frame is marked as updated.
  void DeliverFrame(scoped_refptr<media::VideoFrame> frame,
                    gfx::Rect update_rect,
                    int64_t timestamp_us);

  // |thread_checker_| is bound to the libjingle worker thread.
  THREAD_CHECKER(thread_checker_);
  media::VideoFramePool scaled_frame_pool_;
  // State for the timestamp translation.
  rtc::TimestampAligner timestamp_aligner_;

  const bool is_screencast_;
  const absl::optional<bool> needs_denoising_;

  // Stores the accumulated value of CAPTURE_UPDATE_RECT in case that frames
  // are dropped.
  gfx::Rect accumulated_update_rect_;
  base::Optional<int> previous_capture_counter_;
  gfx::Rect cropping_rect_of_previous_delivered_frame_;

  absl::optional<FrameAdaptationParams>
      custom_frame_adaptation_params_for_testing_;

  DISALLOW_COPY_AND_ASSIGN(WebRtcVideoTrackSource);
};

}  // namespace content

#endif  // CONTENT_RENDERER_MEDIA_WEBRTC_WEBRTC_VIDEO_TRACK_SOURCE_H_