Cleanup the VideoAdapter

webrtc/media/base/videoadapter.h

 /*
  *  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 WEBRTC_MEDIA_BASE_VIDEOADAPTER_H_  // NOLINT
+#ifndef WEBRTC_MEDIA_BASE_VIDEOADAPTER_H_
 #define WEBRTC_MEDIA_BASE_VIDEOADAPTER_H_
 
-#include "webrtc/base/common.h"  // For ASSERT
+#include <limits.h>  // For INT_MAX
+
 #include "webrtc/base/criticalsection.h"
 #include "webrtc/base/optional.h"
-#include "webrtc/base/sigslot.h"
 #include "webrtc/media/base/videocommon.h"
 
 namespace cricket {
 
-class VideoFrame;
-
 // 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.
+// to reduce frame rate and scaling frames.
+// VideoAdapter is thread safe.
 class VideoAdapter {
  public:
   VideoAdapter();
   virtual ~VideoAdapter();
 
-  virtual void SetInputFormat(const VideoFormat& format);
-  void SetOutputFormat(const VideoFormat& format);
-  // Constrain output resolution to this many pixels overall
-  void SetOutputNumPixels(int num_pixels);
-  int GetOutputNumPixels() const;
-
-  const VideoFormat& input_format();
-  // Returns true if the adapter will always return zero size from
-  // AdaptFrameResolution.
-  bool drops_all_frames() const;
-  const VideoFormat& output_format();
+  // Sets the expected frame interval. This controls how often frames should
+  // be dropped if |OnOutputFormatRequest| is called with a lower frame
+  // interval.
+  void SetExpectedInputFrameInterval(int64_t interval);
 
   // Return the adapted resolution given the input resolution. The returned
   // resolution will be 0x0 if the frame should be dropped.
   VideoFormat AdaptFrameResolution(int in_width, int in_height);
 
-  void set_scale_third(bool enable);
-  bool scale_third() const { return scale_third_; }
+  // Requests the output frame size and frame interval from
+  // |AdaptFrameResolution| to not be larger than |format|.
+  void OnOutputFormatRequest(const VideoFormat& format);
 
-  int adaptation_changes() const { return adaption_changes_; }
+  // Requests the output frame size from |AdaptFrameResolution| to not have
+  // more than |max_pixel_count| pixels and have "one step" up more pixels than
+  // max_pixel_count_step_up.
+  void OnResolutionRequest(rtc::Optional<int> max_pixel_count,
+                           rtc::Optional<int> max_pixel_count_step_up);
 
- protected:
-  float FindClosestScale(int width, int height, int target_num_pixels);
-  float FindClosestViewScale(int width, int height, int target_num_pixels);
-  float FindLowerScale(int width, int height, int target_num_pixels);
+  const VideoFormat& input_format() const;
 
  private:
-  const float* GetViewScaleFactors() const;
-  float FindScale(const float* scale_factors,
-                  const float upbias, int width, int height,
-                  int target_num_pixels);
+  void SetInputFormat(const VideoFormat& format);
+  bool Adapt(int max_num_pixels, int max_pixel_count_step_up);
 
   VideoFormat input_format_;
   VideoFormat output_format_;
-  int output_num_pixels_;
-  bool scale_third_;  // True if adapter allows scaling to 1/3 and 2/3.
-  int frames_in_;  // Number of input frames.
-  int frames_out_;  // Number of output frames.
-  int frames_scaled_;  // Number of frames scaled.
-  int adaption_changes_;  // Number of changes in scale factor.
-  size_t previous_width_;  // Previous adapter output width.
-  size_t previous_height_;  // Previous adapter output height.
-  int64_t interval_next_frame_;
+  int output_num_pixels_ = INT_MAX;
+  int frames_in_ = 0;           // Number of input frames.
+  int frames_out_ = 0;          // Number of output frames.
+  int frames_scaled_ = 0;       // Number of frames scaled.
+  int adaption_changes_ = 0;    // Number of changes in scale factor.
+  int previous_width_ = 0;      // Previous adapter output width.
+  int previous_height_ = 0;     // Previous adapter output height.
+  int64_t interval_next_frame_ = 0;
+
+  // Max number of pixels requested via calls to OnOutputFormatRequest,
+  // OnResolutionRequest respectively.
+  // The adapted output format is the minimum of these.
+  int format_request_max_pixel_count_ = INT_MAX;
+  int resolution_request_max_pixel_count_ = INT_MAX;
+
   // The critical section to protect the above variables.
   rtc::CriticalSection critical_section_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(VideoAdapter);
 };
 
-// CoordinatedVideoAdapter adapts the video input to the encoder by coordinating
-// the format request from the server, the resolution request from the encoder,
-// and the CPU load.
-class CoordinatedVideoAdapter
-    : public VideoAdapter, public sigslot::has_slots<>  {
- public:
-  enum AdaptRequest { UPGRADE, KEEP, DOWNGRADE };
-  enum AdaptReasonEnum {
-    ADAPTREASON_NONE = 0,
-    ADAPTREASON_CPU = 1,
-    ADAPTREASON_BANDWIDTH = 2,
-    ADAPTREASON_VIEW = 4
-  };
-  typedef int AdaptReason;
-
-  CoordinatedVideoAdapter();
-  virtual ~CoordinatedVideoAdapter() {}
-
-  virtual void SetInputFormat(const VideoFormat& format);
-
-  // Enable or disable video adaptation due to the change of the CPU load.
-  void set_cpu_adaptation(bool enable) { cpu_adaptation_ = enable; }
-  bool cpu_adaptation() const { return cpu_adaptation_; }
-  // Enable or disable smoothing when doing CPU adaptation. When smoothing is
-  // enabled, system CPU load is tracked using an exponential weighted
-  // average.
-  void set_cpu_smoothing(bool enable);
-  bool cpu_smoothing() const { return cpu_smoothing_; }
-  // Enable or disable video adaptation due to the change of the GD
-  void set_gd_adaptation(bool enable) { gd_adaptation_ = enable; }
-  bool gd_adaptation() const { return gd_adaptation_; }
-  // Enable or disable video adaptation due to the change of the View
-  void set_view_adaptation(bool enable) { view_adaptation_ = enable; }
-  bool view_adaptation() const { return view_adaptation_; }
-  // Enable or disable video adaptation to fast switch View
-  void set_view_switch(bool enable) { view_switch_ = enable; }
-  bool view_switch() const { return view_switch_; }
-
-  CoordinatedVideoAdapter::AdaptReason adapt_reason() const {
-    return adapt_reason_;
-  }
-
-  // When the video is decreased, set the waiting time for CPU adaptation to
-  // decrease video again.
-  void set_cpu_load_min_samples(int cpu_load_min_samples);
-  int cpu_load_min_samples() const { return cpu_load_min_samples_; }
-  // CPU system load high threshold for reducing resolution.  e.g. 0.85f
-  void set_high_system_threshold(float high_system_threshold);
-  float high_system_threshold() const { return high_system_threshold_; }
-  // CPU system load low threshold for increasing resolution.  e.g. 0.70f
-  void set_low_system_threshold(float low_system_threshold);
-  float low_system_threshold() const { return low_system_threshold_; }
-  // CPU process load threshold for reducing resolution.  e.g. 0.10f
-  void set_process_threshold(float process_threshold);
-  float process_threshold() const { return process_threshold_; }
-
-  // Handle the format request from the server via Jingle update message.
-  void OnOutputFormatRequest(const VideoFormat& format);
-  // Handle the resolution request from the encoder due to bandwidth changes.
-  void OnEncoderResolutionRequest(int width, int height, AdaptRequest request);
-  // Handle the resolution request for CPU overuse.
-  void OnCpuResolutionRequest(AdaptRequest request);
-  void OnCpuResolutionRequest(rtc::Optional<int> max_pixel_count,
-                              rtc::Optional<int> max_pixel_count_step_up);
-
-  // Handle the CPU load provided by a CPU monitor.
-  void OnCpuLoadUpdated(int current_cpus, int max_cpus,
-                        float process_load, float system_load);
-
-  sigslot::signal0<> SignalCpuAdaptationUnable;
-
- private:
-  // Adapt to the minimum of the formats the server requests, the CPU wants, and
-  // the encoder wants. Returns true if resolution changed.
-  bool AdaptToMinimumFormat(int* new_width, int* new_height);
-  bool IsMinimumFormat(int pixels);
-  void StepPixelCount(CoordinatedVideoAdapter::AdaptRequest request,
-                      int* num_pixels);
-  CoordinatedVideoAdapter::AdaptRequest FindCpuRequest(
-    int current_cpus, int max_cpus,
-    float process_load, float system_load);
-
-  bool cpu_adaptation_;  // True if cpu adaptation is enabled.
-  bool cpu_smoothing_;  // True if cpu smoothing is enabled (with adaptation).
-  bool gd_adaptation_;  // True if gd adaptation is enabled.
-  bool view_adaptation_;  // True if view adaptation is enabled.
-  bool view_switch_;  // True if view switch is enabled.
-  int cpu_downgrade_count_;
-  int cpu_load_min_samples_;
-  int cpu_load_num_samples_;
-  // cpu system load thresholds relative to max cpus.
-  float high_system_threshold_;
-  float low_system_threshold_;
-  // cpu process load thresholds relative to current cpus.
-  float process_threshold_;
-  // Video formats that the server view requests, the CPU wants, and the encoder
-  // wants respectively. The adapted output format is the minimum of these.
-  int view_desired_num_pixels_;
-  int64_t view_desired_interval_;
-  int encoder_desired_num_pixels_;
-  int cpu_desired_num_pixels_;
-  CoordinatedVideoAdapter::AdaptReason adapt_reason_;
-  // The critical section to protect handling requests.
-  rtc::CriticalSection request_critical_section_;
-
-  // The weighted average of cpu load over time. It's always updated (if cpu
-  // adaptation is on), but only used if cpu_smoothing_ is set.
-  float system_load_average_;
-
-  RTC_DISALLOW_COPY_AND_ASSIGN(CoordinatedVideoAdapter);
-};
-
 }  // namespace cricket
 
-#endif  // WEBRTC_MEDIA_BASE_VIDEOADAPTER_H_  // NOLINT
+#endif  // WEBRTC_MEDIA_BASE_VIDEOADAPTER_H_