Move usage of QualityScaler to ViEEncoder.

webrtc/video_encoder.h

Index: webrtc/video_encoder.h
diff --git a/webrtc/video_encoder.h b/webrtc/video_encoder.h
index f8a04f2e74a9056bf5dbdc4b676e820e83c1ac8a..0a21fa345af6fd86f969d0a646f3d60937f332ec 100644
--- a/webrtc/video_encoder.h
+++ b/webrtc/video_encoder.h
@@ -19,6 +19,7 @@
 #include "webrtc/common_types.h"
 #include "webrtc/typedefs.h"
 #include "webrtc/video_frame.h"
+#include "webrtc/base/optional.h"
 
 namespace webrtc {
 
@@ -59,10 +60,38 @@ class EncodedImageCallback {
       const EncodedImage& encoded_image,
       const CodecSpecificInfo* codec_specific_info,
       const RTPFragmentationHeader* fragmentation) = 0;
+
+  virtual void OnDroppedFrame() {}
 };
 
 class VideoEncoder {
  public:
+  enum EncoderType {
+    kH264,
+    kVp8,
+    kVp9,
+    kUnsupportedCodec,
+  };
+  struct QpThresholds {
+    QpThresholds(int l, int h) : low(l), high(h) {}
+    QpThresholds() : low(-1), high(-1) {}
+    int low;
+    int high;
+  };
+  struct ScalingSettings {
+    ScalingSettings(bool on, int low, int high)
+        : enabled(on),
+          thresholds(rtc::Optional<QpThresholds>(QpThresholds(low, high))) {}
+    explicit ScalingSettings(bool on) : enabled(on) {}
+    const bool enabled;
+    const rtc::Optional<QpThresholds> thresholds;
+  };
+  static VideoEncoder* Create(EncoderType codec_type);
+  // Returns true if this type of encoder can be created using
+  // VideoEncoder::Create.
+  static bool IsSupportedSoftware(EncoderType codec_type);
+  static EncoderType CodecToEncoderType(VideoCodecType codec_type);
+
   static VideoCodecVP8 GetDefaultVp8Settings();
   static VideoCodecVP9 GetDefaultVp9Settings();
   static VideoCodecH264 GetDefaultH264Settings();
@@ -148,8 +177,13 @@ class VideoEncoder {
     return SetRates(allocation.get_sum_kbps(), framerate);
   }
 
+  // Any encoder implementation wishing to use the WebRTC provided
+  // quality scaler must implement this method.
+  virtual ScalingSettings GetScalingSettings() const {
+    return ScalingSettings(false);
+  }
+
   virtual int32_t SetPeriodicKeyFrames(bool enable) { return -1; }
-  virtual void OnDroppedFrame() {}
   virtual bool SupportsNativeHandle() const { return false; }
   virtual const char* ImplementationName() const { return "unknown"; }
 };