New method CreateScaledFrame in the VideoFrameFactory interface.

webrtc/api/androidvideocapturer.cc

Index: webrtc/api/androidvideocapturer.cc
diff --git a/webrtc/api/androidvideocapturer.cc b/webrtc/api/androidvideocapturer.cc
index ee5ef665d97c37247929f170def89192679220d7..70a0a960ca82665d60a1735ff208d6e53b6bdeb1 100644
--- a/webrtc/api/androidvideocapturer.cc
+++ b/webrtc/api/androidvideocapturer.cc
@@ -64,6 +64,42 @@ class AndroidVideoCapturer::FrameFactory : public cricket::VideoFrameFactory {
     return &captured_frame_;
   }
 
+  std::unique_ptr<cricket::VideoFrame> CreateCroppedAndScaledFrame(
+      const cricket::CapturedFrame* input_frame,
+      int crop_x,
+      int crop_y,
+      int crop_width,
+      int crop_height,
+      int dst_width,
+      int dst_height) const override {
+    // Check that input_frame is actually our frame.
+    RTC_CHECK(input_frame == &captured_frame_);
+    // TODO(nisse): Must handle texture frames too.

[perkj_webrtc, 2016/05/16 06:48:46]

I think you have to do this now. CreateAliasedFrame handles textures but since
you override CreateCroppedAndScaledFrame it will not be called?

+    RTC_CHECK(buffer_->native_handle() == nullptr);
+
+    rtc::scoped_refptr<VideoFrameBuffer> scaled_buffer;
+    if (dst_width == crop_width && dst_height == crop_height) {
+      if (dst_width == buffer_->width() && dst_height == buffer_->height()) {
+        scaled_buffer = buffer_;
+      } else {
+        scaled_buffer = WrappedI420Buffer::ShallowCrop(
+            buffer_, crop_x, crop_y, dst_width, dst_height);
+      }
+    }
+    else {
+      scaled_buffer = I420Buffer::CropAndScale(
+          buffer_, crop_x, crop_y, crop_width, crop_height,
+          dst_width, dst_height);
+    }
+    std::unique_ptr<cricket::VideoFrame> frame(
+        new cricket::WebRtcVideoFrame(scaled_buffer,
+                                      input_frame->time_stamp,
+                                      input_frame->rotation));
+    return apply_rotation_ ? std::unique_ptr<cricket::VideoFrame>(
+        frame->GetCopyWithRotationApplied()->Copy())

[perkj_webrtc, 2016/05/16 06:48:46]

nit: Should there be a TODO here to fix GetCopyWithRotationApplied()->Copy()) ?
ie- should GetCopyWithRotationApplied() return a new I420Buffer  so you don't
need to call Copy? The capturer  could potentially cash the rotated buffer if it
has multiple sinks. 

(or we we just pretend that we have not seen this funny thing at the
moment.....)  

+        : std::move(frame);
+  }
+
   cricket::VideoFrame* CreateAliasedFrame(
       const cricket::CapturedFrame* captured_frame,
       int dst_width,