src/modules/video_processing/main/source/content_analysis.cc - vendor/opensource/webrtc - Git at Google

 /*
  *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 #include "content_analysis.h"
 #include "tick_util.h"
 #include "system_wrappers/interface/cpu_features_wrapper.h"

 #include <math.h>
 #include <stdlib.h>

 namespace webrtc {

 VPMContentAnalysis::VPMContentAnalysis(bool runtime_cpu_detection):
 _origFrame(NULL),
 _prevFrame(NULL),
 _width(0),
 _height(0),
 _skipNum(1),
 _border(8),
 _motionMagnitudeNZ(0.0f),
 _spatialPredErr(0.0f),
 _spatialPredErrH(0.0f),
 _spatialPredErrV(0.0f),
 _sizeZeroMotion(0.0f),
 _motionPredErr(0.0f),
 _motionHorizontalness(0.0f),
 _motionClusterDistortion(0.0f),
 _firstFrame(true),
 _CAInit(false),
 _cMetrics(NULL)
 {
     ComputeSpatialMetrics = &VPMContentAnalysis::ComputeSpatialMetrics_C;
     TemporalDiffMetric = &VPMContentAnalysis::TemporalDiffMetric_C;

     if (runtime_cpu_detection)
     {
 #if defined(WEBRTC_ARCH_X86_FAMILY)
         if (WebRtc_GetCPUInfo(kSSE2))
         {
             ComputeSpatialMetrics =
                           &VPMContentAnalysis::ComputeSpatialMetrics_SSE2;
             TemporalDiffMetric = &VPMContentAnalysis::TemporalDiffMetric_SSE2;
         }
 #endif
     }

     Release();
 }

 VPMContentAnalysis::~VPMContentAnalysis()
 {
     Release();
 }


 VideoContentMetrics*
 VPMContentAnalysis::ComputeContentMetrics(const VideoFrame* inputFrame)
 {
     if (inputFrame == NULL)
     {
         return NULL;
     }

     // Init if needed (native dimension change)
     if (_width != inputFrame->Width() || _height != inputFrame->Height())
     {
         if (VPM_OK != Initialize((WebRtc_UWord16)inputFrame->Width(),
                                  (WebRtc_UWord16)inputFrame->Height()))
         {
             return NULL;
         }
     }

     _origFrame = inputFrame->Buffer();

     // compute spatial metrics: 3 spatial prediction errors
     (this->*ComputeSpatialMetrics)();

     // compute motion metrics
     if (_firstFrame == false)
         ComputeMotionMetrics();

     // saving current frame as previous one: Y only
     memcpy(_prevFrame, _origFrame, _width * _height);

     _firstFrame =  false;
     _CAInit = true;

     return ContentMetrics();
 }

 WebRtc_Word32
 VPMContentAnalysis::Release()
 {
     if (_cMetrics != NULL)
     {
         delete _cMetrics;
        _cMetrics = NULL;
     }

     if (_prevFrame != NULL)
     {
         delete [] _prevFrame;
         _prevFrame = NULL;
     }

     _width = 0;
     _height = 0;
     _firstFrame = true;

     return VPM_OK;
 }

 WebRtc_Word32
 VPMContentAnalysis::Initialize(WebRtc_UWord16 width, WebRtc_UWord16 height)
 {
    _width = width;
    _height = height;
    _firstFrame = true;

     // skip parameter: # of skipped rows: for complexity reduction
     //  temporal also currently uses it for column reduction.
     _skipNum = 1;

     // use skipNum = 2 for 4CIF, WHD
     if ( (_height >=  576) && (_width >= 704) )
     {
         _skipNum = 2;
     }
     // use skipNum = 4 for FULLL_HD images
     if ( (_height >=  1080) && (_width >= 1920) )
     {
         _skipNum = 4;
     }

     if (_cMetrics != NULL)
     {
         delete _cMetrics;
     }

     if (_prevFrame != NULL)
     {
         delete [] _prevFrame;
     }

     // Spatial Metrics don't work on a border of 8.  Minimum processing
     // block size is 16 pixels.  So make sure the width and height support this.
     if (_width <= 32 || _height <= 32)
     {
         _CAInit = false;
         return VPM_PARAMETER_ERROR;
     }

     _cMetrics = new VideoContentMetrics();
     if (_cMetrics == NULL)
     {
         return VPM_MEMORY;
     }

     _prevFrame = new WebRtc_UWord8[_width * _height] ; // Y only
     if (_prevFrame == NULL)
     {
         return VPM_MEMORY;
     }

     return VPM_OK;
 }


 // Compute motion metrics: magnitude over non-zero motion vectors,
 //  and size of zero cluster
 WebRtc_Word32
 VPMContentAnalysis::ComputeMotionMetrics()
 {

     // Motion metrics: only one is derived from normalized
     //  (MAD) temporal difference
     (this->*TemporalDiffMetric)();

     return VPM_OK;
 }

 // Normalized temporal difference (MAD): used as a motion level metric
 // Normalize MAD by spatial contrast: images with more contrast
 //  (pixel variance) likely have larger temporal difference
 // To reduce complexity, we compute the metric for a reduced set of points.
 WebRtc_Word32
 VPMContentAnalysis::TemporalDiffMetric_C()
 {
     // size of original frame
     WebRtc_UWord16 sizei = _height;
     WebRtc_UWord16 sizej = _width;

     WebRtc_UWord32 tempDiffSum = 0;
     WebRtc_UWord32 pixelSum = 0;
     WebRtc_UWord64 pixelSqSum = 0;

     WebRtc_UWord32 numPixels = 0; // counter for # of pixels
     WebRtc_UWord32 ssn;

     const WebRtc_Word32 width_end = ((_width - 2*_border) & -16) + _border;

     for(WebRtc_UWord16 i = _border; i < sizei - _border; i += _skipNum)
     {
         for(WebRtc_UWord16 j = _border; j < width_end; j++)
         {
             numPixels += 1;
             ssn =  i * sizej + j;

             WebRtc_UWord8 currPixel  = _origFrame[ssn];
             WebRtc_UWord8 prevPixel  = _prevFrame[ssn];

             tempDiffSum += (WebRtc_UWord32)
                             abs((WebRtc_Word16)(currPixel - prevPixel));
             pixelSum += (WebRtc_UWord32) currPixel;
             pixelSqSum += (WebRtc_UWord64) (currPixel * currPixel);
         }
     }

     // default
     _motionMagnitudeNZ = 0.0f;

     if (tempDiffSum == 0)
     {
         return VPM_OK;
     }

     // normalize over all pixels
     float const tempDiffAvg = (float)tempDiffSum / (float)(numPixels);
     float const pixelSumAvg = (float)pixelSum / (float)(numPixels);
     float const pixelSqSumAvg = (float)pixelSqSum / (float)(numPixels);
     float contrast = pixelSqSumAvg - (pixelSumAvg * pixelSumAvg);

     if (contrast > 0.0)
     {
         contrast = sqrt(contrast);
        _motionMagnitudeNZ = tempDiffAvg/contrast;
     }

     return VPM_OK;

 }

 // Compute spatial metrics:
 // To reduce complexity, we compute the metric for a reduced set of points.
 // The spatial metrics are rough estimates of the prediction error cost for
 //  each QM spatial mode: 2x2,1x2,2x1
 // The metrics are a simple estimate of the up-sampling prediction error,
 // estimated assuming sub-sampling for decimation (no filtering),
 // and up-sampling back up with simple bilinear interpolation.
 WebRtc_Word32
 VPMContentAnalysis::ComputeSpatialMetrics_C()
 {
     //size of original frame
     const WebRtc_UWord16 sizei = _height;
     const WebRtc_UWord16 sizej = _width;

     // pixel mean square average: used to normalize the spatial metrics
     WebRtc_UWord32 pixelMSA = 0;

     WebRtc_UWord32 spatialErrSum = 0;
     WebRtc_UWord32 spatialErrVSum = 0;
     WebRtc_UWord32 spatialErrHSum = 0;

     // make sure work section is a multiple of 16
     const WebRtc_UWord32 width_end = ((sizej - 2*_border) & -16) + _border;

     for(WebRtc_UWord16 i = _border; i < sizei - _border; i += _skipNum)
     {
         for(WebRtc_UWord16 j = _border; j < width_end; j++)
         {
             WebRtc_UWord32 ssn1,ssn2,ssn3,ssn4,ssn5;

             ssn1=  i * sizej + j;
             ssn2 = (i + 1) * sizej + j; // bottom
             ssn3 = (i - 1) * sizej + j; // top
             ssn4 = i * sizej + j + 1;   // right
             ssn5 = i * sizej + j - 1;   // left

             WebRtc_UWord16 refPixel1  = _origFrame[ssn1] << 1;
             WebRtc_UWord16 refPixel2  = _origFrame[ssn1] << 2;

             WebRtc_UWord8 bottPixel = _origFrame[ssn2];
             WebRtc_UWord8 topPixel = _origFrame[ssn3];
             WebRtc_UWord8 rightPixel = _origFrame[ssn4];
             WebRtc_UWord8 leftPixel = _origFrame[ssn5];

             spatialErrSum  += (WebRtc_UWord32) abs((WebRtc_Word16)(refPixel2
                             - (WebRtc_UWord16)(bottPixel + topPixel
                                              + leftPixel + rightPixel)));
             spatialErrVSum += (WebRtc_UWord32) abs((WebRtc_Word16)(refPixel1
                             - (WebRtc_UWord16)(bottPixel + topPixel)));
             spatialErrHSum += (WebRtc_UWord32) abs((WebRtc_Word16)(refPixel1
                             - (WebRtc_UWord16)(leftPixel + rightPixel)));

             pixelMSA += _origFrame[ssn1];
         }
     }

     // normalize over all pixels
     const float spatialErr  = (float)(spatialErrSum >> 2);
     const float spatialErrH = (float)(spatialErrHSum >> 1);
     const float spatialErrV = (float)(spatialErrVSum >> 1);
     const float norm = (float)pixelMSA;

     // 2X2:
     _spatialPredErr = spatialErr / norm;

     // 1X2:
     _spatialPredErrH = spatialErrH / norm;

     // 2X1:
     _spatialPredErrV = spatialErrV / norm;

     return VPM_OK;
 }

 VideoContentMetrics*
 VPMContentAnalysis::ContentMetrics()
 {
     if (_CAInit == false)
     {
         return NULL;
     }


     _cMetrics->spatialPredErr = _spatialPredErr;
     _cMetrics->spatialPredErrH = _spatialPredErrH;
     _cMetrics->spatialPredErrV = _spatialPredErrV;
     // normalized temporal difference (MAD)
     _cMetrics->motionMagnitudeNZ = _motionMagnitudeNZ;

     // Set to zero: not computed
     _cMetrics->motionPredErr = _motionPredErr;
     _cMetrics->sizeZeroMotion = _sizeZeroMotion;
     _cMetrics->motionHorizontalness = _motionHorizontalness;
     _cMetrics->motionClusterDistortion = _motionClusterDistortion;

     return _cMetrics;

 }

 } // namespace
	/*
	* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
	*
	* Use of this source code is governed by a BSD-style license
	* that can be found in the LICENSE file in the root of the source
	* tree. An additional intellectual property rights grant can be found
	* in the file PATENTS. All contributing project authors may
	* be found in the AUTHORS file in the root of the source tree.
	*/
	#include "content_analysis.h"
	#include "tick_util.h"
	#include "system_wrappers/interface/cpu_features_wrapper.h"

	#include <math.h>
	#include <stdlib.h>

	namespace webrtc {

	VPMContentAnalysis::VPMContentAnalysis(bool runtime_cpu_detection):
	_origFrame(NULL),
	_prevFrame(NULL),
	_width(0),
	_height(0),
	_skipNum(1),
	_border(8),
	_motionMagnitudeNZ(0.0f),
	_spatialPredErr(0.0f),
	_spatialPredErrH(0.0f),
	_spatialPredErrV(0.0f),
	_sizeZeroMotion(0.0f),
	_motionPredErr(0.0f),
	_motionHorizontalness(0.0f),
	_motionClusterDistortion(0.0f),
	_firstFrame(true),
	_CAInit(false),
	_cMetrics(NULL)
	{
	ComputeSpatialMetrics = &VPMContentAnalysis::ComputeSpatialMetrics_C;
	TemporalDiffMetric = &VPMContentAnalysis::TemporalDiffMetric_C;

	if (runtime_cpu_detection)
	{
	#if defined(WEBRTC_ARCH_X86_FAMILY)
	if (WebRtc_GetCPUInfo(kSSE2))
	{
	ComputeSpatialMetrics =
	&VPMContentAnalysis::ComputeSpatialMetrics_SSE2;
	TemporalDiffMetric = &VPMContentAnalysis::TemporalDiffMetric_SSE2;
	}
	#endif
	}

	Release();
	}

	VPMContentAnalysis::~VPMContentAnalysis()
	{
	Release();
	}


	VideoContentMetrics*
	VPMContentAnalysis::ComputeContentMetrics(const VideoFrame* inputFrame)
	{
	if (inputFrame == NULL)
	{
	return NULL;
	}

	// Init if needed (native dimension change)
	if (_width != inputFrame->Width() \|\| _height != inputFrame->Height())
	{
	if (VPM_OK != Initialize((WebRtc_UWord16)inputFrame->Width(),
	(WebRtc_UWord16)inputFrame->Height()))
	{
	return NULL;
	}
	}

	_origFrame = inputFrame->Buffer();

	// compute spatial metrics: 3 spatial prediction errors
	(this->*ComputeSpatialMetrics)();

	// compute motion metrics
	if (_firstFrame == false)
	ComputeMotionMetrics();

	// saving current frame as previous one: Y only
	memcpy(_prevFrame, _origFrame, _width * _height);

	_firstFrame = false;
	_CAInit = true;

	return ContentMetrics();
	}

	WebRtc_Word32
	VPMContentAnalysis::Release()
	{
	if (_cMetrics != NULL)
	{
	delete _cMetrics;
	_cMetrics = NULL;
	}

	if (_prevFrame != NULL)
	{
	delete [] _prevFrame;
	_prevFrame = NULL;
	}

	_width = 0;
	_height = 0;
	_firstFrame = true;

	return VPM_OK;
	}

	WebRtc_Word32
	VPMContentAnalysis::Initialize(WebRtc_UWord16 width, WebRtc_UWord16 height)
	{
	_width = width;
	_height = height;
	_firstFrame = true;

	// skip parameter: # of skipped rows: for complexity reduction
	// temporal also currently uses it for column reduction.
	_skipNum = 1;

	// use skipNum = 2 for 4CIF, WHD
	if ( (_height >= 576) && (_width >= 704) )
	{
	_skipNum = 2;
	}
	// use skipNum = 4 for FULLL_HD images
	if ( (_height >= 1080) && (_width >= 1920) )
	{
	_skipNum = 4;
	}

	if (_cMetrics != NULL)
	{
	delete _cMetrics;
	}

	if (_prevFrame != NULL)
	{
	delete [] _prevFrame;
	}

	// Spatial Metrics don't work on a border of 8. Minimum processing
	// block size is 16 pixels. So make sure the width and height support this.
	if (_width <= 32 \|\| _height <= 32)
	{
	_CAInit = false;
	return VPM_PARAMETER_ERROR;
	}

	_cMetrics = new VideoContentMetrics();
	if (_cMetrics == NULL)
	{
	return VPM_MEMORY;
	}

	_prevFrame = new WebRtc_UWord8[_width * _height] ; // Y only
	if (_prevFrame == NULL)
	{
	return VPM_MEMORY;
	}

	return VPM_OK;
	}


	// Compute motion metrics: magnitude over non-zero motion vectors,
	// and size of zero cluster
	WebRtc_Word32
	VPMContentAnalysis::ComputeMotionMetrics()
	{

	// Motion metrics: only one is derived from normalized
	// (MAD) temporal difference
	(this->*TemporalDiffMetric)();

	return VPM_OK;
	}

	// Normalized temporal difference (MAD): used as a motion level metric
	// Normalize MAD by spatial contrast: images with more contrast
	// (pixel variance) likely have larger temporal difference
	// To reduce complexity, we compute the metric for a reduced set of points.
	WebRtc_Word32
	VPMContentAnalysis::TemporalDiffMetric_C()
	{
	// size of original frame
	WebRtc_UWord16 sizei = _height;
	WebRtc_UWord16 sizej = _width;

	WebRtc_UWord32 tempDiffSum = 0;
	WebRtc_UWord32 pixelSum = 0;
	WebRtc_UWord64 pixelSqSum = 0;

	WebRtc_UWord32 numPixels = 0; // counter for # of pixels
	WebRtc_UWord32 ssn;

	const WebRtc_Word32 width_end = ((_width - 2*_border) & -16) + _border;

	for(WebRtc_UWord16 i = _border; i < sizei - _border; i += _skipNum)
	{
	for(WebRtc_UWord16 j = _border; j < width_end; j++)
	{
	numPixels += 1;
	ssn = i * sizej + j;

	WebRtc_UWord8 currPixel = _origFrame[ssn];
	WebRtc_UWord8 prevPixel = _prevFrame[ssn];

	tempDiffSum += (WebRtc_UWord32)
	abs((WebRtc_Word16)(currPixel - prevPixel));
	pixelSum += (WebRtc_UWord32) currPixel;
	pixelSqSum += (WebRtc_UWord64) (currPixel * currPixel);
	}
	}

	// default
	_motionMagnitudeNZ = 0.0f;

	if (tempDiffSum == 0)
	{
	return VPM_OK;
	}

	// normalize over all pixels
	float const tempDiffAvg = (float)tempDiffSum / (float)(numPixels);
	float const pixelSumAvg = (float)pixelSum / (float)(numPixels);
	float const pixelSqSumAvg = (float)pixelSqSum / (float)(numPixels);
	float contrast = pixelSqSumAvg - (pixelSumAvg * pixelSumAvg);

	if (contrast > 0.0)
	{
	contrast = sqrt(contrast);
	_motionMagnitudeNZ = tempDiffAvg/contrast;
	}

	return VPM_OK;

	}

	// Compute spatial metrics:
	// To reduce complexity, we compute the metric for a reduced set of points.
	// The spatial metrics are rough estimates of the prediction error cost for
	// each QM spatial mode: 2x2,1x2,2x1
	// The metrics are a simple estimate of the up-sampling prediction error,
	// estimated assuming sub-sampling for decimation (no filtering),
	// and up-sampling back up with simple bilinear interpolation.
	WebRtc_Word32
	VPMContentAnalysis::ComputeSpatialMetrics_C()
	{
	//size of original frame
	const WebRtc_UWord16 sizei = _height;
	const WebRtc_UWord16 sizej = _width;

	// pixel mean square average: used to normalize the spatial metrics
	WebRtc_UWord32 pixelMSA = 0;

	WebRtc_UWord32 spatialErrSum = 0;
	WebRtc_UWord32 spatialErrVSum = 0;
	WebRtc_UWord32 spatialErrHSum = 0;

	// make sure work section is a multiple of 16
	const WebRtc_UWord32 width_end = ((sizej - 2*_border) & -16) + _border;

	for(WebRtc_UWord16 i = _border; i < sizei - _border; i += _skipNum)
	{
	for(WebRtc_UWord16 j = _border; j < width_end; j++)
	{
	WebRtc_UWord32 ssn1,ssn2,ssn3,ssn4,ssn5;

	ssn1= i * sizej + j;
	ssn2 = (i + 1) * sizej + j; // bottom
	ssn3 = (i - 1) * sizej + j; // top
	ssn4 = i * sizej + j + 1; // right
	ssn5 = i * sizej + j - 1; // left

	WebRtc_UWord16 refPixel1 = _origFrame[ssn1] << 1;
	WebRtc_UWord16 refPixel2 = _origFrame[ssn1] << 2;

	WebRtc_UWord8 bottPixel = _origFrame[ssn2];
	WebRtc_UWord8 topPixel = _origFrame[ssn3];
	WebRtc_UWord8 rightPixel = _origFrame[ssn4];
	WebRtc_UWord8 leftPixel = _origFrame[ssn5];

	spatialErrSum += (WebRtc_UWord32) abs((WebRtc_Word16)(refPixel2
	- (WebRtc_UWord16)(bottPixel + topPixel
	+ leftPixel + rightPixel)));
	spatialErrVSum += (WebRtc_UWord32) abs((WebRtc_Word16)(refPixel1
	- (WebRtc_UWord16)(bottPixel + topPixel)));
	spatialErrHSum += (WebRtc_UWord32) abs((WebRtc_Word16)(refPixel1
	- (WebRtc_UWord16)(leftPixel + rightPixel)));

	pixelMSA += _origFrame[ssn1];
	}
	}

	// normalize over all pixels
	const float spatialErr = (float)(spatialErrSum >> 2);
	const float spatialErrH = (float)(spatialErrHSum >> 1);
	const float spatialErrV = (float)(spatialErrVSum >> 1);
	const float norm = (float)pixelMSA;

	// 2X2:
	_spatialPredErr = spatialErr / norm;

	// 1X2:
	_spatialPredErrH = spatialErrH / norm;

	// 2X1:
	_spatialPredErrV = spatialErrV / norm;

	return VPM_OK;
	}

	VideoContentMetrics*
	VPMContentAnalysis::ContentMetrics()
	{
	if (_CAInit == false)
	{
	return NULL;
	}


	_cMetrics->spatialPredErr = _spatialPredErr;
	_cMetrics->spatialPredErrH = _spatialPredErrH;
	_cMetrics->spatialPredErrV = _spatialPredErrV;
	// normalized temporal difference (MAD)
	_cMetrics->motionMagnitudeNZ = _motionMagnitudeNZ;

	// Set to zero: not computed
	_cMetrics->motionPredErr = _motionPredErr;
	_cMetrics->sizeZeroMotion = _sizeZeroMotion;
	_cMetrics->motionHorizontalness = _motionHorizontalness;
	_cMetrics->motionClusterDistortion = _motionClusterDistortion;

	return _cMetrics;

	}

	} // namespace