Repo created

TMessagesProj/jni/voip/webrtc/media/base/video_adapter.h

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+/*
+ *  Copyright (c) 2010 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 MEDIA_BASE_VIDEO_ADAPTER_H_
+#define MEDIA_BASE_VIDEO_ADAPTER_H_
+
+#include <stdint.h>
+
+#include <string>
+#include <utility>
+
+#include "absl/types/optional.h"
+#include "api/video/video_source_interface.h"
+#include "common_video/framerate_controller.h"
+#include "media/base/video_common.h"
+#include "rtc_base/synchronization/mutex.h"
+#include "rtc_base/system/rtc_export.h"
+#include "rtc_base/thread_annotations.h"
+
+namespace cricket {
+
+// VideoAdapter adapts an input video frame to an output frame based on the
+// specified input and output formats. The adaptation includes dropping frames
+// to reduce frame rate and scaling frames.
+// VideoAdapter is thread safe.
+class RTC_EXPORT VideoAdapter {
+ public:
+  VideoAdapter();
+  // The source requests output frames whose width and height are divisible
+  // by `source_resolution_alignment`.
+  explicit VideoAdapter(int source_resolution_alignment);
+  virtual ~VideoAdapter();
+
+  VideoAdapter(const VideoAdapter&) = delete;
+  VideoAdapter& operator=(const VideoAdapter&) = delete;
+
+  // Return the adapted resolution and cropping parameters given the
+  // input resolution. The input frame should first be cropped, then
+  // scaled to the final output resolution. Returns true if the frame
+  // should be adapted, and false if it should be dropped.
+  bool AdaptFrameResolution(int in_width,
+                            int in_height,
+                            int64_t in_timestamp_ns,
+                            int* cropped_width,
+                            int* cropped_height,
+                            int* out_width,
+                            int* out_height) RTC_LOCKS_EXCLUDED(mutex_);
+
+  // DEPRECATED. Please use OnOutputFormatRequest below.
+  // TODO(asapersson): Remove this once it is no longer used.
+  // Requests the output frame size and frame interval from
+  // `AdaptFrameResolution` to not be larger than `format`. Also, the input
+  // frame size will be cropped to match the requested aspect ratio. The
+  // requested aspect ratio is orientation agnostic and will be adjusted to
+  // maintain the input orientation, so it doesn't matter if e.g. 1280x720 or
+  // 720x1280 is requested.
+  // Note: Should be called from the source only.
+  void OnOutputFormatRequest(const absl::optional<VideoFormat>& format)
+      RTC_LOCKS_EXCLUDED(mutex_);
+
+  // Requests output frame size and frame interval from `AdaptFrameResolution`.
+  // `target_aspect_ratio`: The input frame size will be cropped to match the
+  // requested aspect ratio. The aspect ratio is orientation agnostic and will
+  // be adjusted to maintain the input orientation (i.e. it doesn't matter if
+  // e.g. <1280,720> or <720,1280> is requested).
+  // `max_pixel_count`: The maximum output frame size.
+  // `max_fps`: The maximum output framerate.
+  // Note: Should be called from the source only.
+  void OnOutputFormatRequest(
+      const absl::optional<std::pair<int, int>>& target_aspect_ratio,
+      const absl::optional<int>& max_pixel_count,
+      const absl::optional<int>& max_fps) RTC_LOCKS_EXCLUDED(mutex_);
+
+  // Same as above, but allows setting two different target aspect ratios
+  // depending on incoming frame orientation. This gives more fine-grained
+  // control and can e.g. be used to force landscape video to be cropped to
+  // portrait video.
+  void OnOutputFormatRequest(
+      const absl::optional<std::pair<int, int>>& target_landscape_aspect_ratio,
+      const absl::optional<int>& max_landscape_pixel_count,
+      const absl::optional<std::pair<int, int>>& target_portrait_aspect_ratio,
+      const absl::optional<int>& max_portrait_pixel_count,
+      const absl::optional<int>& max_fps) RTC_LOCKS_EXCLUDED(mutex_);
+
+  // Requests the output frame size from `AdaptFrameResolution` to have as close
+  // as possible to `sink_wants.target_pixel_count` pixels (if set)
+  // but no more than `sink_wants.max_pixel_count`.
+  // `sink_wants.max_framerate_fps` is essentially analogous to
+  // `sink_wants.max_pixel_count`, but for framerate rather than resolution.
+  // Set `sink_wants.max_pixel_count` and/or `sink_wants.max_framerate_fps` to
+  // std::numeric_limit<int>::max() if no upper limit is desired.
+  // The sink resolution alignment requirement is given by
+  // `sink_wants.resolution_alignment`.
+  // Note: Should be called from the sink only.
+  void OnSinkWants(const rtc::VideoSinkWants& sink_wants)
+      RTC_LOCKS_EXCLUDED(mutex_);
+
+  // Returns maximum image area, which shouldn't impose any adaptations.
+  // Can return `numeric_limits<int>::max()` if no limit is set.
+  int GetTargetPixels() const;
+
+  // Returns current frame-rate limit.
+  // Can return `numeric_limits<float>::infinity()` if no limit is set.
+  float GetMaxFramerate() const;
+
+ private:
+  // Determine if frame should be dropped based on input fps and requested fps.
+  bool DropFrame(int64_t in_timestamp_ns) RTC_EXCLUSIVE_LOCKS_REQUIRED(mutex_);
+
+  int frames_in_ RTC_GUARDED_BY(mutex_);      // Number of input frames.
+  int frames_out_ RTC_GUARDED_BY(mutex_);     // Number of output frames.
+  int frames_scaled_ RTC_GUARDED_BY(mutex_);  // Number of frames scaled.
+  int adaption_changes_
+      RTC_GUARDED_BY(mutex_);  // Number of changes in scale factor.
+  int previous_width_ RTC_GUARDED_BY(mutex_);  // Previous adapter output width.
+  int previous_height_
+      RTC_GUARDED_BY(mutex_);  // Previous adapter output height.
+  const bool variable_start_scale_factor_;
+
+  // The fixed source resolution alignment requirement.
+  const int source_resolution_alignment_;
+  // The currently applied resolution alignment, as given by the requirements:
+  //  - the fixed `source_resolution_alignment_`; and
+  //  - the latest `sink_wants.resolution_alignment`.
+  int resolution_alignment_ RTC_GUARDED_BY(mutex_);
+
+  // Max number of pixels/fps requested via calls to OnOutputFormatRequest,
+  // OnResolutionFramerateRequest respectively.
+  // The adapted output format is the minimum of these.
+  struct OutputFormatRequest {
+    absl::optional<std::pair<int, int>> target_landscape_aspect_ratio;
+    absl::optional<int> max_landscape_pixel_count;
+    absl::optional<std::pair<int, int>> target_portrait_aspect_ratio;
+    absl::optional<int> max_portrait_pixel_count;
+    absl::optional<int> max_fps;
+
+    // For logging.
+    std::string ToString() const;
+  };
+
+  OutputFormatRequest output_format_request_ RTC_GUARDED_BY(mutex_);
+  int resolution_request_target_pixel_count_ RTC_GUARDED_BY(mutex_);
+  int resolution_request_max_pixel_count_ RTC_GUARDED_BY(mutex_);
+  int max_framerate_request_ RTC_GUARDED_BY(mutex_);
+
+  // Stashed OutputFormatRequest that is used to save value of
+  // OnOutputFormatRequest in case all active encoders are using
+  // requested_resolution. I.e when all active encoders are using
+  // requested_resolution, the call to OnOutputFormatRequest is ignored
+  // and the value from requested_resolution is used instead (to scale/crop
+  // frame). This allows for an application to only use
+  // RtpEncodingParameters::request_resolution and get the same behavior as if
+  // it had used VideoAdapter::OnOutputFormatRequest.
+  absl::optional<OutputFormatRequest> stashed_output_format_request_
+      RTC_GUARDED_BY(mutex_);
+
+  webrtc::FramerateController framerate_controller_ RTC_GUARDED_BY(mutex_);
+
+  // The critical section to protect the above variables.
+  mutable webrtc::Mutex mutex_;
+};
+
+}  // namespace cricket
+
+#endif  // MEDIA_BASE_VIDEO_ADAPTER_H_