tests: silence a few type related warnings Change-Id: If908328c1dbbb5bd84c57e30fab1cda1804933e4

diff --git a/test/ivf_video_source.h b/test/ivf_video_source.h
index 88bc597..926f801 100644
--- a/test/ivf_video_source.h
+++ b/test/ivf_video_source.h

@@ -47,7 +47,8 @@
   virtual void Init() {
     // Allocate a buffer for read in the compressed video frame.
     compressed_frame_buf_ = new uint8_t[libvpx_test::kCodeBufferSize];
-    ASSERT_TRUE(compressed_frame_buf_) << "Allocate frame buffer failed";
+    ASSERT_TRUE(compressed_frame_buf_ != NULL)
+        << "Allocate frame buffer failed";
   }
 
   virtual void Begin() {

diff --git a/test/subtract_test.cc b/test/subtract_test.cc
index 81bfb66..574bfbf 100644
--- a/test/subtract_test.cc
+++ b/test/subtract_test.cc

@@ -61,7 +61,7 @@
     int16_t *src_diff = be.src_diff;
     for (int r = 0; r < kBlockHeight; ++r) {
       for (int c = 0; c < kBlockWidth; ++c) {
-        src_diff[c] = 0xa5a5;
+        src_diff[c] = static_cast<int16_t>(0xa5a5);
       }
       src_diff += kDiffPredStride;
     }

diff --git a/test/util.h b/test/util.h
index 533a1db..4d7f3d4 100644
--- a/test/util.h
+++ b/test/util.h

@@ -37,7 +37,7 @@
                   img2->planes[VPX_PLANE_Y][i * img2->stride[VPX_PLANE_Y] + j];
       sqrerr += d * d;
     }
-  double mse = sqrerr / (width_y * height_y);
+  double mse = static_cast<double>(sqrerr) / (width_y * height_y);
   double psnr = 100.0;
   if (mse > 0.0) {
     psnr = 10 * log10(255.0 * 255.0 / mse);