vpm: removing unnecessary memcpy

TEST=trybots

BUG=1128

Review URL: https://webrtc-codereview.appspot.com/966038

git-svn-id: http://webrtc.googlecode.com/svn/trunk/webrtc@3284 4adac7df-926f-26a2-2b94-8c16560cd09d

4 files changed, 31 insertions, 19 deletions

diff --git a/modules/video_processing/main/interface/video_processing.h b/modules/video_processing/main/interface/video_processing.h
index fbee00d9..1aaade3c 100644
--- a/modules/video_processing/main/interface/video_processing.h
+++ b/modules/video_processing/main/interface/video_processing.h
@@ -266,7 +266,8 @@ public:
     virtual WebRtc_UWord32 DecimatedHeight() const = 0 ;
 
     /**
-    Set the spatial resampling settings of the VPM: The resampler may either be disabled or one of the following:
+    Set the spatial resampling settings of the VPM: The resampler may either be
+    disabled or one of the following:
     scaling to a close to target dimension followed by crop/pad
 
     \param[in] resamplingMode
@@ -279,8 +280,8 @@ public:
     Get Processed (decimated) frame
 	  
     \param[in] frame pointer to the video frame.
-	  
-	  \param[in] processedFrame pointer (double) to the processed frame
+    \param[in] processedFrame pointer (double) to the processed frame. If no
+               processing is required, processedFrame will be NULL.
     
     \return VPM_OK on success, a negative value on error (see error codes)
     */
diff --git a/modules/video_processing/main/source/frame_preprocessor.cc b/modules/video_processing/main/source/frame_preprocessor.cc
index 58805416..4b342cef 100644
--- a/modules/video_processing/main/source/frame_preprocessor.cc
+++ b/modules/video_processing/main/source/frame_preprocessor.cc
@@ -152,9 +152,8 @@ VPMFramePreprocessor::PreprocessFrame(const I420VideoFrame& frame,
         return 1;  // drop 1 frame
     }
 
-    // Resizing incoming frame if needed.
-    // Note that we must make a copy of it.
-    // We are not allowed to resample the input frame.
+    // Resizing incoming frame if needed. Otherwise, remains NULL.
+    // We are not allowed to resample the input frame (must make a copy of it).
     *processedFrame = NULL;
     if (_spatialResampler->ApplyResample(frame.width(), frame.height()))  {
       WebRtc_Word32 ret = _spatialResampler->ResampleFrame(frame,
diff --git a/modules/video_processing/main/source/spatial_resampler.cc b/modules/video_processing/main/source/spatial_resampler.cc
index 5f1359fa..207260e4 100644
--- a/modules/video_processing/main/source/spatial_resampler.cc
+++ b/modules/video_processing/main/source/spatial_resampler.cc
@@ -65,12 +65,13 @@ WebRtc_Word32
 VPMSimpleSpatialResampler::ResampleFrame(const I420VideoFrame& inFrame,
                                          I420VideoFrame* outFrame)
 {
+  // Don't copy if frame remains as is.
   if (_resamplingMode == kNoRescaling)
-     return outFrame->CopyFrame(inFrame);
+     return VPM_OK;
   // Check if re-sampling is needed
-  if ((inFrame.width() == _targetWidth) &&
+  else if ((inFrame.width() == _targetWidth) &&
     (inFrame.height() == _targetHeight))  {
-    return outFrame->CopyFrame(inFrame);
+    return VPM_OK;
   }
 
   // Setting scaler
diff --git a/modules/video_processing/main/test/unit_test/unit_test.cc b/modules/video_processing/main/test/unit_test/unit_test.cc
index c29808a7..e4775fc0 100644
--- a/modules/video_processing/main/test/unit_test/unit_test.cc
+++ b/modules/video_processing/main/test/unit_test/unit_test.cc
@@ -213,20 +213,31 @@ TEST_F(VideoProcessingModuleTest, FrameStats)
 
 TEST_F(VideoProcessingModuleTest, PreprocessorLogic)
 {
-  // Disable temporal sampling
+  // Disable temporal sampling.
+  int resolution = 100;
   _vpm->EnableTemporalDecimation(false);
-  ASSERT_EQ(VPM_OK, _vpm->SetMaxFrameRate(30));
-  ASSERT_EQ(VPM_OK, _vpm->SetTargetResolution(100, 100, 15));
+  EXPECT_EQ(VPM_OK, _vpm->SetMaxFrameRate(30));
+  EXPECT_EQ(VPM_OK, _vpm->SetTargetResolution(resolution, resolution, 15));
   // Revert
   _vpm->EnableTemporalDecimation(true);
-  ASSERT_EQ(VPM_OK, _vpm->SetTargetResolution(100, 100, 30));
-  // Disable spatial sampling
+  EXPECT_EQ(VPM_OK, _vpm->SetTargetResolution(resolution, resolution, 30));
+  // Disable spatial sampling.
   _vpm->SetInputFrameResampleMode(kNoRescaling);
-  ASSERT_EQ(VPM_OK, _vpm->SetTargetResolution(100, 100, 30));
-  I420VideoFrame *outFrame = NULL;
-  ASSERT_EQ(VPM_OK, _vpm->PreprocessFrame(_videoFrame, &outFrame));
-  // No rescaling=> output frame = NULL
-  ASSERT_TRUE(outFrame == NULL);
+  EXPECT_EQ(VPM_OK, _vpm->SetTargetResolution(resolution, resolution, 30));
+  I420VideoFrame* outFrame = NULL;
+  // Set rescaling => output frame != NULL.
+  _vpm->SetInputFrameResampleMode(kFastRescaling);
+  EXPECT_EQ(VPM_OK, _vpm->SetTargetResolution(resolution, resolution, 30));
+  EXPECT_EQ(VPM_OK, _vpm->PreprocessFrame(_videoFrame, &outFrame));
+  EXPECT_FALSE(outFrame == NULL);
+  if (outFrame) {
+    EXPECT_EQ(resolution, outFrame->width());
+    EXPECT_EQ(resolution, outFrame->height());
+  }
+  // No rescaling=> output frame = NULL.
+  _vpm->SetInputFrameResampleMode(kNoRescaling);
+  EXPECT_EQ(VPM_OK, _vpm->PreprocessFrame(_videoFrame, &outFrame));
+  EXPECT_TRUE(outFrame == NULL);
 }
 
 TEST_F(VideoProcessingModuleTest, Resampler)