Handle scaling frames in RTCVideoEncoder

content/renderer/media/gpu/rtc_video_encoder.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/renderer/media/gpu/rtc_video_encoder.h"
 
 #include <string.h>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ skipping 567 matching lines @@
     frame = media::VideoFrame::WrapExternalSharedMemory(
         media::PIXEL_FORMAT_I420, input_frame_coded_size_,
         gfx::Rect(input_visible_size_), input_visible_size_,
         reinterpret_cast<uint8_t*>(input_buffer->memory()),
         input_buffer->mapped_size(), input_buffer->handle(), 0, timestamp);
     if (!frame.get()) {
       LogAndNotifyError(FROM_HERE, "failed to create frame",
                         media::VideoEncodeAccelerator::kPlatformFailureError);
       return;
     }
-    // Do a strided copy of the input frame to match the input requirements for
-    // the encoder.
-    // TODO(sheu): support zero-copy from WebRTC.  http://crbug.com/269312
-    if (libyuv::I420Copy(next_frame->video_frame_buffer()->DataY(),
-                         next_frame->video_frame_buffer()->StrideY(),
-                         next_frame->video_frame_buffer()->DataU(),
-                         next_frame->video_frame_buffer()->StrideU(),
-                         next_frame->video_frame_buffer()->DataV(),
-                         next_frame->video_frame_buffer()->StrideV(),
-                         frame->data(media::VideoFrame::kYPlane),
-                         frame->stride(media::VideoFrame::kYPlane),
-                         frame->data(media::VideoFrame::kUPlane),
-                         frame->stride(media::VideoFrame::kUPlane),
-                         frame->data(media::VideoFrame::kVPlane),
-                         frame->stride(media::VideoFrame::kVPlane),
-                         next_frame->width(), next_frame->height())) {
+
+    // Do a strided copy and scale (if necessary) the input frame to match
+    // the input requirements for the encoder.
+    // TODO(sheu): Support zero-copy from WebRTC. http://crbug.com/269312
+    // TODO(magjed): Downscale with kFilterBox in an image pyramid instead.
+    if (libyuv::I420Scale(next_frame->video_frame_buffer()->DataY(),
+                          next_frame->video_frame_buffer()->StrideY(),
+                          next_frame->video_frame_buffer()->DataU(),
+                          next_frame->video_frame_buffer()->StrideU(),
+                          next_frame->video_frame_buffer()->DataV(),
+                          next_frame->video_frame_buffer()->StrideV(),
+                          next_frame->width(), next_frame->height(),
+                          frame->visible_data(media::VideoFrame::kYPlane),
+                          frame->stride(media::VideoFrame::kYPlane),
+                          frame->visible_data(media::VideoFrame::kUPlane),
+                          frame->stride(media::VideoFrame::kUPlane),
+                          frame->visible_data(media::VideoFrame::kVPlane),
+                          frame->stride(media::VideoFrame::kVPlane),
+                          frame->visible_rect().width(),
+                          frame->visible_rect().height(),
+                          libyuv::kFilterBox)) {
       LogAndNotifyError(FROM_HERE, "Failed to copy buffer",
                         media::VideoEncodeAccelerator::kPlatformFailureError);
       return;
     }
   }
   frame->AddDestructionObserver(media::BindToCurrentLoop(
       base::Bind(&RTCVideoEncoder::Impl::EncodeFrameFinished, this, index)));
   video_encoder_->Encode(frame, next_frame_keyframe);
   input_buffers_free_.pop_back();
   SignalAsyncWaiter(WEBRTC_VIDEO_CODEC_OK);
@@ skipping 260 matching lines @@
   UMA_HISTOGRAM_BOOLEAN("Media.RTCVideoEncoderInitEncodeSuccess",
                         init_retval == WEBRTC_VIDEO_CODEC_OK);
   if (init_retval == WEBRTC_VIDEO_CODEC_OK) {
     UMA_HISTOGRAM_ENUMERATION("Media.RTCVideoEncoderProfile",
                               profile,
                               media::VIDEO_CODEC_PROFILE_MAX + 1);
   }
 }
 
 }  // namespace content