video_processing: Adding logic to avoid a memcpy when not required

Review URL: http://webrtc-codereview.appspot.com/255002

git-svn-id: http://webrtc.googlecode.com/svn/trunk@858 4adac7df-926f-26a2-2b94-8c16560cd09d

src/modules/video_processing/main/source/frame_preprocessor.cc

@@ -139,14 +139,11 @@ VPMFramePreprocessor::DecimatedHeight() const
 WebRtc_Word32
 VPMFramePreprocessor::PreprocessFrame(const VideoFrame* frame, VideoFrame** processedFrame)
 {
-    if (frame == NULL)
+    if (frame == NULL || frame->Height() == 0 || frame->Width() == 0)
-    {
-        return VPM_PARAMETER_ERROR;
-    }
-    else if (frame->Height() == 0 || frame->Width() == 0)
     {
         return VPM_PARAMETER_ERROR;
     }
+
     _vd->UpdateIncomingFrameRate();
 
     if (_vd->DropFrame())
@@ -155,25 +152,30 @@ VPMFramePreprocessor::PreprocessFrame(const VideoFrame* frame, VideoFrame** proc
         return 1;  // drop 1 frame
     }
 
-    //Resizing incoming frame.
+    // Resizing incoming frame if needed.
-    // Note that we must make a copy of it. We are not allowed to resample the input frame.
+    // Note that we must make a copy of it.
+    // We are not allowed to resample the input frame.
+    *processedFrame = NULL;
+    if (_spatialResampler->ApplyResample(frame->Width(), frame->Height()))  {
       WebRtc_Word32 ret = _spatialResampler->ResampleFrame(*frame, _resampledFrame);
       if (ret != VPM_OK)
-    {
         return ret;
+      *processedFrame = &_resampledFrame;
     }
 
-    *processedFrame = &_resampledFrame;
+    // Perform content analysis on the frame to be encoded
-
-    // Perform content analysis on the resampled frame
     if (_enableCA)
     {
+        if (*processedFrame == NULL)  {
+          _contentMetrics = _ca->ComputeContentMetrics(frame);
+        } else {
           _contentMetrics = _ca->ComputeContentMetrics(&_resampledFrame);
+        }
         // Update native values:
         _contentMetrics->nativeHeight = frame->Height();
         _contentMetrics->nativeWidth = frame->Width();
-
+        // Max value as set by user
-        _contentMetrics->nativeFrameRate = _maxFrameRate; // max value as set by user 
+        _contentMetrics->nativeFrameRate = _maxFrameRate;
     }
     return VPM_OK;
 }

src/modules/video_processing/main/source/spatial_resampler.cc

@@ -371,5 +371,16 @@ VPMSimpleSpatialResampler::TargetWidth()
     return _targetWidth;
 }
 
+bool
+VPMSimpleSpatialResampler::ApplyResample(WebRtc_UWord32 width,
+                                         WebRtc_UWord32 height)
+{
+    if ((width == _targetWidth && height == _targetHeight) ||
+        _resamplingMode == kNoRescaling)
+      return false;
+    else
+      return true;
+}
+
 
 } //namespace

src/modules/video_processing/main/source/spatial_resampler.h

@@ -39,6 +39,7 @@ public:
     virtual WebRtc_UWord32 TargetWidth() = 0;
     virtual WebRtc_UWord32 TargetHeight() = 0;
     virtual WebRtc_Word32 Release() = 0;
+    virtual bool ApplyResample(WebRtc_UWord32 width, WebRtc_UWord32 height) = 0;
 };
 
 class VPMSimpleSpatialResampler : public VPMSpatialResampler
@@ -55,6 +56,7 @@ public:
     virtual WebRtc_UWord32 TargetWidth();
     virtual WebRtc_UWord32 TargetHeight();
     virtual WebRtc_Word32 Release();
+    virtual bool ApplyResample(WebRtc_UWord32 width, WebRtc_UWord32 height);
 
 private:
     WebRtc_Word32 UpsampleFrame(const VideoFrame& inFrame, VideoFrame& outFrame);

src/modules/video_processing/main/source/video_processing_impl.h

@@ -11,6 +11,7 @@
 /*
  * video_processing_impl.h
  */
+
 #ifndef WEBRTC_MODULE_VIDEO_PROCESSING_IMPL_H
 #define WEBRTC_MODULE_VIDEO_PROCESSING_IMPL_H
 
@@ -80,15 +81,21 @@ public:
     virtual WebRtc_Word32 SetMaxFrameRate(WebRtc_UWord32 maxFrameRate);
 	
     // Set Target Resolution: frame rate and dimension
-    virtual WebRtc_Word32 SetTargetResolution(WebRtc_UWord32 width, WebRtc_UWord32 height, WebRtc_UWord32 frameRate);
+    virtual WebRtc_Word32 SetTargetResolution(WebRtc_UWord32 width,
+                                              WebRtc_UWord32 height,
+                                              WebRtc_UWord32 frameRate);
 
     // Get decimated values: frame rate/dimension
     virtual WebRtc_UWord32 DecimatedFrameRate();
     virtual WebRtc_UWord32 DecimatedWidth() const;
     virtual WebRtc_UWord32 DecimatedHeight() const;
 
-    // Preprocess:
+    // Pre-process:
-    virtual WebRtc_Word32 PreprocessFrame(const VideoFrame* frame, VideoFrame** processedFrame);
+    // Pre-process incoming frame: Sample when needed and compute content metrics
+    // when enable.
+    // If no resampling takes place - processedFrame is set to NULL.
+    virtual WebRtc_Word32 PreprocessFrame(const VideoFrame* frame,
+                                          VideoFrame** processedFrame);
     virtual VideoContentMetrics* ContentMetrics() const;
 
 private:

src/video_engine/main/source/vie_encoder.cc

@@ -585,6 +585,11 @@ void ViEEncoder::DeliverFrame(int id, webrtc::VideoFrame& videoFrame,
         VideoContentMetrics* contentMetrics = NULL;
         contentMetrics = _vpm.ContentMetrics();
 
+        // frame was not sampled => use original
+        if (decimatedFrame == NULL)  {
+          decimatedFrame = &videoFrame;
+        }
+
         if (_vcm.AddVideoFrame
             (*decimatedFrame, contentMetrics, &codecSpecificInfo) != VCM_OK)
         {
@@ -609,6 +614,10 @@ void ViEEncoder::DeliverFrame(int id, webrtc::VideoFrame& videoFrame,
                   "%s: Error preprocessing frame %u", __FUNCTION__, videoFrame.TimeStamp());
         return;
     }
+    // frame was not sampled => use original
+    if (decimatedFrame == NULL)  {
+      decimatedFrame = &videoFrame;
+    }
     if (_vcm.AddVideoFrame(*decimatedFrame) != VCM_OK)
     {
         WEBRTC_TRACE(webrtc::kTraceError, webrtc::kTraceVideo,