Refactor VideoDenoiser to use a buffer pool, replacing explicit double buffering.

webrtc/modules/video_processing/video_denoiser.h

Index: webrtc/modules/video_processing/video_denoiser.h
diff --git a/webrtc/modules/video_processing/video_denoiser.h b/webrtc/modules/video_processing/video_denoiser.h
index 5293a9902b11169e11dc0fbe925de21c2552df3a..e67bd59e68f424558f5cfeae0f4ff5f4c6fbf7dd 100644
--- a/webrtc/modules/video_processing/video_denoiser.h
+++ b/webrtc/modules/video_processing/video_denoiser.h
@@ -13,6 +13,7 @@
 
 #include <memory>
 
+#include "webrtc/common_video/include/i420_buffer_pool.h"
 #include "webrtc/modules/video_processing/util/denoiser_filter.h"
 #include "webrtc/modules/video_processing/util/noise_estimation.h"
 #include "webrtc/modules/video_processing/util/skin_detection.h"
@@ -23,21 +24,12 @@ class VideoDenoiser {
  public:
   explicit VideoDenoiser(bool runtime_cpu_detection);
 
-  // TODO(nisse): Let the denoised_frame and denoised_frame_prev be
-  // member variables referencing two I420Buffer, and return a refptr
-  // to the current one. When we also move the double-buffering logic
-  // from the caller.
-  void DenoiseFrame(const rtc::scoped_refptr<VideoFrameBuffer>& frame,
-                    // Buffers are allocated/replaced when dimensions
-                    // change.
-                    rtc::scoped_refptr<I420Buffer>* denoised_frame,
-                    rtc::scoped_refptr<I420Buffer>* denoised_frame_prev,
-                    bool noise_estimation_enabled);
+  rtc::scoped_refptr<VideoFrameBuffer> DenoiseFrame(
+      rtc::scoped_refptr<VideoFrameBuffer> frame,
+      bool noise_estimation_enabled);
 
  private:
-  void DenoiserReset(const rtc::scoped_refptr<VideoFrameBuffer>& frame,
-                     rtc::scoped_refptr<I420Buffer>* denoised_frame,
-                     rtc::scoped_refptr<I420Buffer>* denoised_frame_prev);
+  void DenoiserReset(rtc::scoped_refptr<VideoFrameBuffer> frame);
 
   // Check the mb position, return 1: close to the frame center (between 1/8
   // and 7/8 of width/height), 3: close to the border (out of 1/16 and 15/16
@@ -56,18 +48,21 @@ class VideoDenoiser {
                        int mb_col);
 
   // Copy input blocks to dst buffer on moving object blocks (MOB).
-  void CopySrcOnMOB(const uint8_t* y_src, uint8_t* y_dst);
+  void CopySrcOnMOB(const uint8_t* y_src,
+                    int stride_src,
+                    uint8_t* y_dst,
+                    int stride_dst);
 
   // Copy luma margin blocks when frame width/height not divisible by 16.
-  void CopyLumaOnMargin(const uint8_t* y_src, uint8_t* y_dst);
+  void CopyLumaOnMargin(const uint8_t* y_src,
+                        int stride_src,
+                        uint8_t* y_dst,
+                        int stride_dst);
 
   int width_;
   int height_;
   int mb_rows_;
   int mb_cols_;
-  int stride_y_;
-  int stride_u_;
-  int stride_v_;
   CpuType cpu_type_;
   std::unique_ptr<DenoiserFilter> filter_;
   std::unique_ptr<NoiseEstimation> ne_;
@@ -80,6 +75,8 @@ class VideoDenoiser {
   std::unique_ptr<uint8_t[]> y_density_;
   // Save the return values by MbDenoise for each block.
   std::unique_ptr<DenoiserDecision[]> mb_filter_decision_;
+  I420BufferPool buffer_pool_;
+  rtc::scoped_refptr<VideoFrameBuffer> prev_buffer_;
 };
 
 }  // namespace webrtc