Move usage of QualityScaler to ViEEncoder.

webrtc/video_encoder.h

 /*
  *  Copyright (c) 2014 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_VIDEO_ENCODER_H_
 #define WEBRTC_VIDEO_ENCODER_H_
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "webrtc/common_types.h"
 #include "webrtc/typedefs.h"
 #include "webrtc/video_frame.h"
+#include "webrtc/base/optional.h"
 
 namespace webrtc {
 
 class RTPFragmentationHeader;
 // TODO(pbos): Expose these through a public (root) header or change these APIs.
 struct CodecSpecificInfo;
 struct VideoCodec;
 
 class EncodedImageCallback {
  public:
@@ skipping 43 matching lines @@
 };
 
 class VideoEncoder {
  public:
   enum EncoderType {
     kH264,
     kVp8,
     kVp9,
     kUnsupportedCodec,
   };
+  typedef std::pair<int, int> QPThresholds;

[magjed_webrtc, 2016/10/07 12:02:54]

I think it would be better to make this a real class instead and add a static
factory function for the default values. The default values can then be moved
from the quality scaler to that function. Something like:
class QPThresholds {
 public:
  static rtc::Optional<QPThresholds> Default(EncoderType encoderType);
  
  QPThresholds(int lower_bound, int upper_bound);

  int GetLowerBound();
  int GetUpperBound(); 

 private:
  const int lower_bound_;
  const int upper_bound_;
};

 
   static VideoEncoder* Create(EncoderType codec_type);
 
   static VideoCodecVP8 GetDefaultVp8Settings();
   static VideoCodecVP9 GetDefaultVp9Settings();
   static VideoCodecH264 GetDefaultH264Settings();
 
   virtual ~VideoEncoder() {}
 
   // Initialize the encoder with the information from the codecSettings
@@ skipping 58 matching lines @@
 
   // Inform the encoder about the new target bit rate.
   //
   // Input:
   //          - bitrate         : New target bit rate
   //          - framerate       : The target frame rate
   //
   // Return value                : WEBRTC_VIDEO_CODEC_OK if OK, < 0 otherwise.
   virtual int32_t SetRates(uint32_t bitrate, uint32_t framerate) = 0;
 
+  // If a specific set of thresholds are desired for quality scaling
+  // an encoder implementation can override this method.
+  virtual rtc::Optional<QPThresholds> GetQPThresholds() {
+    return rtc::Optional<QPThresholds>();
+  }
+
   virtual int32_t SetPeriodicKeyFrames(bool enable) { return -1; }
   virtual void OnDroppedFrame() {}
   virtual bool SupportsNativeHandle() const { return false; }
   virtual const char* ImplementationName() const { return "unknown"; }
 };
 
 // Class used to wrap external VideoEncoders to provide a fallback option on
 // software encoding when a hardware encoder fails to encode a stream due to
 // hardware restrictions, such as max resolution.
 class VideoEncoderSoftwareFallbackWrapper : public VideoEncoder {
@@ skipping 39 matching lines @@
 
   const EncoderType encoder_type_;
   webrtc::VideoEncoder* const encoder_;
 
   std::unique_ptr<webrtc::VideoEncoder> fallback_encoder_;
   std::string fallback_implementation_name_;
   EncodedImageCallback* callback_;
 };
 }  // namespace webrtc
 #endif  // WEBRTC_VIDEO_ENCODER_H_