Reland of Optimize Android NV12 capture

webrtc/api/androidvideotracksource.cc

Index: webrtc/api/androidvideotracksource.cc
diff --git a/webrtc/api/androidvideotracksource.cc b/webrtc/api/androidvideotracksource.cc
index 7fd033efec55ba63c1b592d7aa17b60167c7c36c..f0bd26a510e647d0156193f8e59e91ccbdf44f78 100644
--- a/webrtc/api/androidvideotracksource.cc
+++ b/webrtc/api/androidvideotracksource.cc
@@ -12,6 +12,8 @@
 
 #include <utility>
 
+#include "third_party/libyuv/include/libyuv/rotate.h"
+
 namespace webrtc {
 
 AndroidVideoTrackSource::AndroidVideoTrackSource(rtc::Thread* signaling_thread,
@@ -106,42 +108,51 @@ void AndroidVideoTrackSource::OnByteBufferFrameCaptured(const void* frame_data,
     return;
   }
 
-  int rotated_width = crop_width;
-  int rotated_height = crop_height;
-
-  rtc::CritScope lock(&apply_rotation_crit_);
-  if (apply_rotation_ && (rotation == 90 || rotation == 270)) {
-    std::swap(adapted_width, adapted_height);
-    std::swap(rotated_width, rotated_height);
-  }
-
-  rtc::scoped_refptr<webrtc::I420Buffer> buffer =
-      pre_scale_pool_.CreateBuffer(rotated_width, rotated_height);
-
   const uint8_t* y_plane = static_cast<const uint8_t*>(frame_data);
   const uint8_t* uv_plane = y_plane + width * height;
-  int uv_width = (width + 1) / 2;
+  const int uv_width = (width + 1) / 2;
 
   RTC_CHECK_GE(length, width * height + 2 * uv_width * ((height + 1) / 2));
 
   // Can only crop at even pixels.
   crop_x &= ~1;
   crop_y &= ~1;
+  // Crop just by modifying pointers.
+  y_plane += width * crop_y + crop_x;
+  uv_plane += uv_width * crop_y + crop_x;
+
+  rtc::scoped_refptr<webrtc::I420Buffer> buffer =
+      buffer_pool_.CreateBuffer(adapted_width, adapted_height);
 
-  libyuv::NV12ToI420Rotate(
-      y_plane + width * crop_y + crop_x, width,
-      uv_plane + uv_width * crop_y + crop_x, width, buffer->MutableDataY(),
-      buffer->StrideY(),
+  nv12toi420_scaler_.NV12ToI420Scale(
+      y_plane, width,
+      uv_plane, uv_width * 2,
+      crop_width, crop_height,
+      buffer->MutableDataY(), buffer->StrideY(),
       // Swap U and V, since we have NV21, not NV12.
-      buffer->MutableDataV(), buffer->StrideV(), buffer->MutableDataU(),
-      buffer->StrideU(), crop_width, crop_height,
-      static_cast<libyuv::RotationMode>(apply_rotation_ ? rotation : 0));
-
-  if (adapted_width != buffer->width() || adapted_height != buffer->height()) {
-    rtc::scoped_refptr<webrtc::I420Buffer> scaled_buffer(
-        post_scale_pool_.CreateBuffer(adapted_width, adapted_height));
-    scaled_buffer->ScaleFrom(buffer);
-    buffer = scaled_buffer;
+      buffer->MutableDataV(), buffer->StrideV(),
+      buffer->MutableDataU(), buffer->StrideU(),
+      buffer->width(), buffer->height());
+
+  // Applying rotation is only supported for legacy reasons, and the performance
+  // for this path is not critical.
+  rtc::CritScope lock(&apply_rotation_crit_);
+  if (apply_rotation_ && rotation != 0) {
+    rtc::scoped_refptr<I420Buffer> rotated_buffer =
+        rotation == 180 ? I420Buffer::Create(buffer->width(), buffer->height())
+                        : I420Buffer::Create(buffer->height(), buffer->width());
+
+    libyuv::I420Rotate(
+        buffer->DataY(), buffer->StrideY(),
+        buffer->DataU(), buffer->StrideU(),
+        buffer->DataV(), buffer->StrideV(),
+        rotated_buffer->MutableDataY(), rotated_buffer->StrideY(),
+        rotated_buffer->MutableDataU(), rotated_buffer->StrideU(),
+        rotated_buffer->MutableDataV(), rotated_buffer->StrideV(),
+        buffer->width(), buffer->height(),
+        static_cast<libyuv::RotationMode>(rotation));
+
+    buffer = rotated_buffer;
   }
 
   OnFrame(cricket::WebRtcVideoFrame(