Added Vp9 simulcast tests.

webrtc/common_video/libyuv/webrtc_libyuv.cc

Index: webrtc/common_video/libyuv/webrtc_libyuv.cc
diff --git a/webrtc/common_video/libyuv/webrtc_libyuv.cc b/webrtc/common_video/libyuv/webrtc_libyuv.cc
index ae8d6b1ef58ddb6cf8d4ceeab07fd1696462566d..5fb9900656784dfe7cdf9df6a3a5094fa8ecfeb6 100644
--- a/webrtc/common_video/libyuv/webrtc_libyuv.cc
+++ b/webrtc/common_video/libyuv/webrtc_libyuv.cc
@@ -288,22 +288,37 @@ int ConvertFromI420(const VideoFrame& src_frame,
       ConvertVideoType(dst_video_type));
 }
 
-// Compute PSNR for an I420 frame (all planes)
+// Compute PSNR for an I420 frame (all planes). Can upscale test frame.
 double I420PSNR(const VideoFrameBuffer& ref_buffer,
                 const VideoFrameBuffer& test_buffer) {
-  if ((ref_buffer.width() != test_buffer.width()) ||
-      (ref_buffer.height() != test_buffer.height()))
+  rtc::scoped_refptr<const VideoFrameBuffer> temp_buffer(&test_buffer);
+  if ((ref_buffer.width() < test_buffer.width()) ||

[magjed_webrtc, 2017/02/13 15:35:11]

I don't think we need these checks. Can we simply do:
if (ref_buffer.width() != test_buffer.width() || 
    ref_buffer.height() != test_buffer.height()) {
  ...scale...
}
instead?

[ilnik, 2017/02/13 16:54:25]

Scaling down is not an intended behavior here, so I guess we should not do it
like you suggest. Or we can do it like you ask, but include RTC_CHECKs. What do
you think?

[magjed_webrtc, 2017/02/14 12:47:49]

I don't see the problem of making the code more general if it works and
simplifies the code, but sure, keep the RTC_DCHECKS if you want to catch these
cases.

+      (ref_buffer.height() < test_buffer.height())) {
     return -1;
-  else if (ref_buffer.width() < 0 || ref_buffer.height() < 0)
+  } else if (ref_buffer.width() < 0 || ref_buffer.height() < 0) {
     return -1;
-
-  double psnr = libyuv::I420Psnr(ref_buffer.DataY(), ref_buffer.StrideY(),
-                                 ref_buffer.DataU(), ref_buffer.StrideU(),
-                                 ref_buffer.DataV(), ref_buffer.StrideV(),
-                                 test_buffer.DataY(), test_buffer.StrideY(),
-                                 test_buffer.DataU(), test_buffer.StrideU(),
-                                 test_buffer.DataV(), test_buffer.StrideV(),
-                                 test_buffer.width(), test_buffer.height());
+  } else if ((ref_buffer.width() > test_buffer.width()) ||
+             (ref_buffer.height() > test_buffer.height())) {
+    rtc::scoped_refptr<I420Buffer> scaled_buffer =
+        I420Buffer::Create(ref_buffer.width(), ref_buffer.height());
+    if (libyuv::I420Scale(

[magjed_webrtc, 2017/02/13 15:35:11]

Can you use 'scaled_buffer.ScaleFrom(test_buffer)' instead?

[ilnik, 2017/02/13 16:54:25]

Yes, it turns out, it will be equivalent. Will change to that.

+            test_buffer.DataY(), test_buffer.StrideY(), test_buffer.DataU(),
+            test_buffer.StrideU(), test_buffer.DataV(), test_buffer.StrideV(),
+            test_buffer.width(), test_buffer.height(),
+            scaled_buffer->MutableDataY(), scaled_buffer->StrideY(),
+            scaled_buffer->MutableDataU(), scaled_buffer->StrideU(),
+            scaled_buffer->MutableDataV(), scaled_buffer->StrideV(),
+            scaled_buffer->width(), scaled_buffer->height(),
+            libyuv::kFilterBilinear) != 0)
+      return -1;
+    temp_buffer = static_cast<VideoFrameBuffer*>(scaled_buffer.release());
+  }
+  double psnr = libyuv::I420Psnr(
+      ref_buffer.DataY(), ref_buffer.StrideY(), ref_buffer.DataU(),
+      ref_buffer.StrideU(), ref_buffer.DataV(), ref_buffer.StrideV(),
+      temp_buffer->DataY(), temp_buffer->StrideY(), temp_buffer->DataU(),
+      temp_buffer->StrideU(), temp_buffer->DataV(), temp_buffer->StrideV(),
+      temp_buffer->width(), temp_buffer->height());
   // LibYuv sets the max psnr value to 128, we restrict it here.
   // In case of 0 mse in one frame, 128 can skew the results significantly.
   return (psnr > kPerfectPSNR) ? kPerfectPSNR : psnr;
@@ -317,22 +332,37 @@ double I420PSNR(const VideoFrame* ref_frame, const VideoFrame* test_frame) {
                   *test_frame->video_frame_buffer());
 }
 
-// Compute SSIM for an I420 frame (all planes)
+// Compute SSIM for an I420 frame (all planes). Can upscale test_buffer.
 double I420SSIM(const VideoFrameBuffer& ref_buffer,
                 const VideoFrameBuffer& test_buffer) {
-  if ((ref_buffer.width() != test_buffer.width()) ||
-      (ref_buffer.height() != test_buffer.height()))
+  rtc::scoped_refptr<const VideoFrameBuffer> temp_buffer(&test_buffer);
+  if ((ref_buffer.width() < test_buffer.width()) ||
+      (ref_buffer.height() < test_buffer.height())) {
     return -1;
-  else if (ref_buffer.width() < 0 || ref_buffer.height() < 0)
+  } else if (ref_buffer.width() < 0 || ref_buffer.height() < 0) {
     return -1;
-
-  return libyuv::I420Ssim(ref_buffer.DataY(), ref_buffer.StrideY(),
-                          ref_buffer.DataU(), ref_buffer.StrideU(),
-                          ref_buffer.DataV(), ref_buffer.StrideV(),
-                          test_buffer.DataY(), test_buffer.StrideY(),
-                          test_buffer.DataU(), test_buffer.StrideU(),
-                          test_buffer.DataV(), test_buffer.StrideV(),
-                          test_buffer.width(), test_buffer.height());
+  } else if ((ref_buffer.width() > test_buffer.width()) ||
+             (ref_buffer.height() > test_buffer.height())) {
+    rtc::scoped_refptr<I420Buffer> scaled_buffer =
+        I420Buffer::Create(ref_buffer.width(), ref_buffer.height());
+    if (libyuv::I420Scale(
+            test_buffer.DataY(), test_buffer.StrideY(), test_buffer.DataU(),
+            test_buffer.StrideU(), test_buffer.DataV(), test_buffer.StrideV(),
+            test_buffer.width(), test_buffer.height(),
+            scaled_buffer->MutableDataY(), scaled_buffer->StrideY(),
+            scaled_buffer->MutableDataU(), scaled_buffer->StrideU(),
+            scaled_buffer->MutableDataV(), scaled_buffer->StrideV(),
+            scaled_buffer->width(), scaled_buffer->height(),
+            libyuv::kFilterBilinear) != 0)
+      return -1;
+    temp_buffer = static_cast<VideoFrameBuffer*>(scaled_buffer.release());

[ilnik, 2017/02/13 16:54:25]

Fixed potential memory corruption. If no scaling were done temp_buffer acquired
responsibility for test_buffer and deleted it at the end of function.

+  }
+  return libyuv::I420Ssim(
+      ref_buffer.DataY(), ref_buffer.StrideY(), ref_buffer.DataU(),
+      ref_buffer.StrideU(), ref_buffer.DataV(), ref_buffer.StrideV(),
+      temp_buffer->DataY(), temp_buffer->StrideY(), temp_buffer->DataU(),
+      temp_buffer->StrideU(), temp_buffer->DataV(), temp_buffer->StrideV(),
+      temp_buffer->width(), temp_buffer->height());
 }
 double I420SSIM(const VideoFrame* ref_frame, const VideoFrame* test_frame) {
   if (!ref_frame || !test_frame)