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TMessagesProj/jni/voip/webrtc/api/video/video_source_interface.h

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+/*
+ *  Copyright (c) 2016 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.
+ */
+
+#ifndef API_VIDEO_VIDEO_SOURCE_INTERFACE_H_
+#define API_VIDEO_VIDEO_SOURCE_INTERFACE_H_
+
+#include <limits>
+#include <vector>
+
+#include "absl/types/optional.h"
+#include "api/video/video_sink_interface.h"
+#include "rtc_base/system/rtc_export.h"
+
+namespace rtc {
+
+// VideoSinkWants is used for notifying the source of properties a video frame
+// should have when it is delivered to a certain sink.
+struct RTC_EXPORT VideoSinkWants {
+  struct FrameSize {
+    FrameSize(int width, int height) : width(width), height(height) {}
+    FrameSize(const FrameSize&) = default;
+    ~FrameSize() = default;
+
+    int width;
+    int height;
+  };
+
+  VideoSinkWants();
+  VideoSinkWants(const VideoSinkWants&);
+  ~VideoSinkWants();
+
+  // Tells the source whether the sink wants frames with rotation applied.
+  // By default, any rotation must be applied by the sink.
+  bool rotation_applied = false;
+
+  // Tells the source that the sink only wants black frames.
+  bool black_frames = false;
+
+  // Tells the source the maximum number of pixels the sink wants.
+  int max_pixel_count = std::numeric_limits<int>::max();
+  // Tells the source the desired number of pixels the sinks wants. This will
+  // typically be used when stepping the resolution up again when conditions
+  // have improved after an earlier downgrade. The source should select the
+  // closest resolution to this pixel count, but if max_pixel_count is set, it
+  // still sets the absolute upper bound.
+  absl::optional<int> target_pixel_count;
+  // Tells the source the maximum framerate the sink wants.
+  int max_framerate_fps = std::numeric_limits<int>::max();
+
+  // Tells the source that the sink wants width and height of the video frames
+  // to be divisible by `resolution_alignment`.
+  // For example: With I420, this value would be a multiple of 2.
+  // Note that this field is unrelated to any horizontal or vertical stride
+  // requirements the encoder has on the incoming video frame buffers.
+  int resolution_alignment = 1;
+
+  // The resolutions that sink is configured to consume. If the sink is an
+  // encoder this is what the encoder is configured to encode. In singlecast we
+  // only encode one resolution, but in simulcast and SVC this can mean multiple
+  // resolutions per frame.
+  //
+  // The sink is always configured to consume a subset of the
+  // webrtc::VideoFrame's resolution. In the case of encoding, we usually encode
+  // at webrtc::VideoFrame's resolution but this may not always be the case due
+  // to scaleResolutionDownBy or turning off simulcast or SVC layers.
+  //
+  // For example, we may capture at 720p and due to adaptation (e.g. applying
+  // `max_pixel_count` constraints) create webrtc::VideoFrames of size 480p, but
+  // if we do scaleResolutionDownBy:2 then the only resolution we end up
+  // encoding is 240p. In this case we still need to provide webrtc::VideoFrames
+  // of size 480p but we can optimize internal buffers for 240p, avoiding
+  // downsampling to 480p if possible.
+  //
+  // Note that the `resolutions` can change while frames are in flight and
+  // should only be used as a hint when constructing the webrtc::VideoFrame.
+  std::vector<FrameSize> resolutions;
+
+  // This is the resolution requested by the user using RtpEncodingParameters.
+  absl::optional<FrameSize> requested_resolution;
+
+  // `is_active` : Is this VideoSinkWants from an encoder that is encoding any
+  // layer. IF YES, it will affect how the VideoAdapter will choose to
+  // prioritize the OnOutputFormatRequest vs. requested_resolution. IF NO,
+  // VideoAdapter consider this VideoSinkWants as a passive listener (e.g a
+  // VideoRenderer or a VideoEncoder that is not currently actively encoding).
+  bool is_active = false;
+
+  // This sub-struct contains information computed by VideoBroadcaster
+  // that aggregates several VideoSinkWants (and sends them to
+  // AdaptedVideoTrackSource).
+  struct Aggregates {
+    // `active_without_requested_resolution` is set by VideoBroadcaster
+    // when aggregating sink wants if there exists any sink (encoder) that is
+    // active but has not set the `requested_resolution`, i.e is relying on
+    // OnOutputFormatRequest to handle encode resolution.
+    bool any_active_without_requested_resolution = false;
+  };
+  absl::optional<Aggregates> aggregates;
+};
+
+inline bool operator==(const VideoSinkWants::FrameSize& a,
+                       const VideoSinkWants::FrameSize& b) {
+  return a.width == b.width && a.height == b.height;
+}
+
+inline bool operator!=(const VideoSinkWants::FrameSize& a,
+                       const VideoSinkWants::FrameSize& b) {
+  return !(a == b);
+}
+
+template <typename VideoFrameT>
+class VideoSourceInterface {
+ public:
+  virtual ~VideoSourceInterface() = default;
+
+  virtual void AddOrUpdateSink(VideoSinkInterface<VideoFrameT>* sink,
+                               const VideoSinkWants& wants) = 0;
+  // RemoveSink must guarantee that at the time the method returns,
+  // there is no current and no future calls to VideoSinkInterface::OnFrame.
+  virtual void RemoveSink(VideoSinkInterface<VideoFrameT>* sink) = 0;
+
+  // Request underlying source to capture a new frame.
+  // TODO(crbug/1255737): make pure virtual once downstream projects adapt.
+  virtual void RequestRefreshFrame() {}
+};
+
+}  // namespace rtc
+#endif  // API_VIDEO_VIDEO_SOURCE_INTERFACE_H_