New method CreateScaledFrame in the VideoFrameFactory interface.

webrtc/media/engine/webrtcvideoframefactory.cc

Index: webrtc/media/engine/webrtcvideoframefactory.cc
diff --git a/webrtc/media/engine/webrtcvideoframefactory.cc b/webrtc/media/engine/webrtcvideoframefactory.cc
index 2c08c63129c6c28303a743d5122bf69d6e0f57d3..e2a0c04f4ba11640d725bd7d2c6ec346f56805e6 100644
--- a/webrtc/media/engine/webrtcvideoframefactory.cc
+++ b/webrtc/media/engine/webrtcvideoframefactory.cc
@@ -10,12 +10,89 @@
 
 #include <memory>
 
+#include "libyuv/convert.h"
+#include "libyuv/scale.h"
+
 #include "webrtc/base/logging.h"
+// #include "webrtc/common_video/include/video_frame_buffer.h"

[magjed_webrtc, 2016/05/09 10:58:08]

remove if not used

[nisse-webrtc, 2016/05/09 11:06:01]

Done.

 #include "webrtc/media/engine/webrtcvideoframe.h"
 #include "webrtc/media/engine/webrtcvideoframefactory.h"
 
+// TODO(nisse): Needed for the struct CapturedFrame. Move declaration
+// to videoframefactory.h instead?
+#include "webrtc/media/base/videocapturer.h"
+
 namespace cricket {
 
+std::unique_ptr<VideoFrame> WebRtcVideoFrameFactory::CreateScaledFrame(
+    const CapturedFrame* input_frame,
+    int width,
+    int height) const {
+  webrtc::VideoRotation rotation = input_frame->rotation;
+  int rotated_width;
+  int rotated_height;
+  if (apply_rotation_ && (rotation == webrtc::kVideoRotation_90 ||
+                          rotation == webrtc::kVideoRotation_270)) {
+    rotated_width = input_frame->height;
+    rotated_height = input_frame->width;
+  } else {
+    rotated_width = input_frame->width;
+    rotated_height = input_frame->height;
+  }
+  uint32_t format = CanonicalFourCC(input_frame->fourcc);

[magjed_webrtc, 2016/05/09 10:58:08]

Move this to the line above libyuv::ConvertToI420.

[nisse-webrtc, 2016/05/09 11:06:01]

Done.

+  rtc::scoped_refptr<webrtc::I420Buffer> buffer(
+      new rtc::RefCountedObject<webrtc::I420Buffer>(rotated_width,
+                                                    rotated_height));
+
+  // TODO(nisse): Do center crop if needed to preserve aspect ratio.

[magjed_webrtc, 2016/05/09 10:58:08]

I would like if you implemented this immediately. Maybe the name should be
changed as well? Also, if we want all implementations to center crop to preserve
aspect ratio, we should document it in the interface.

[nisse-webrtc, 2016/05/09 11:06:01]

Ok, I'll give it a try.

+  // Old code carried a comment saying that MJPG can only be cropped
+  // vertically, and disabled cropping in this case.
+
+  // Color space conversion, and rotation.
+  int r = libyuv::ConvertToI420(
+      static_cast<const uint8_t*>(input_frame->data), input_frame->data_size,
+      buffer->MutableDataY(), buffer->StrideY(),
+      buffer->MutableDataU(), buffer->StrideU(),
+      buffer->MutableDataV(), buffer->StrideV(),
+      0, 0, /* No cropping. */
+      buffer->width(), buffer->height(),
+      rotated_width, rotated_height,
+      static_cast<libyuv::RotationMode>(
+          apply_rotation_ ? rotation : webrtc::kVideoRotation_0),
+      format);
+  if (r) {
+    LOG(LS_ERROR) << "Error parsing format: " << GetFourccName(format)
+                  << " return code : " << r;
+    return nullptr;
+  }
+
+  // Scaling, if needed. Currently doesn't respect aspect ratio.
+  if (rotated_width != width || rotated_height != height) {
+    rtc::scoped_refptr<webrtc::I420Buffer> scaled(
+        new rtc::RefCountedObject<webrtc::I420Buffer>(width, height));
+
+    if (libyuv::I420Scale(buffer->DataY(), buffer->StrideY(),
+                          buffer->DataU(), buffer->StrideU(),
+                          buffer->DataV(), buffer->StrideV(),
+                          buffer->width(), buffer->height(),
+                          scaled->MutableDataY(), scaled->StrideY(),
+                          scaled->MutableDataU(), scaled->StrideU(),
+                          scaled->MutableDataV(), scaled->StrideV(),
+                          scaled->width(), scaled->height(),
+                          libyuv::kFilterBox) < 0) {
+      LOG(LS_ERROR) << "I420Scale failed: src size "
+                    << buffer->width() << " x " << buffer->height()
+                    << ", dst size: "
+                    << scaled->width() << " x " << scaled->height();
+      return nullptr;
+    }
+    buffer = scaled;
+  }
+  return std::unique_ptr<VideoFrame>(new WebRtcVideoFrame(
+      buffer, apply_rotation_ ? webrtc::kVideoRotation_0 : rotation,
+      input_frame->time_stamp / rtc::kNumNanosecsPerMicrosec));
+}
+
 VideoFrame* WebRtcVideoFrameFactory::CreateAliasedFrame(
     const CapturedFrame* aliased_frame, int width, int height) const {
   std::unique_ptr<WebRtcVideoFrame> frame(new WebRtcVideoFrame());