SENSVideoStream Class Reference

#include <SENSVideoStream.h>

Public Member Functions
	SENSVideoStream (const std::string &videoFileName, bool videoLoops, bool mirrorH, bool mirrorV, float targetFps=0)
SENSFramePtr	grabNextFrame ()
SENSFramePtr	grabNextResampledFrame ()
SENSFramePtr	grabPreviousResampledFrame ()
SENSFramePtr	grabPreviousFrame ()
cv::Size	getFrameSize () const
const std::string &	videoFilename () const
int	nextFrameIndex () const
int	frameCount () const
float	fps () const
bool	isOpened () const
const SENSCalibration *const	calibration () const
void	setCalibration (SENSCalibration calibration, bool buildUndistortionMaps)
void	guessAndSetCalibration (float fovGuess)

Private Member Functions
void	moveCapturePosition (int n)

Private Attributes
cv::VideoCapture	_cap
cv::Size2i	_videoFrameSize
int	_frameCount = 0
std::string	_videoFileName
bool	_videoLoops = false
float	_fps = 0.f
float	_targetFps
bool	_mirrorH = false
bool	_mirrorV = false
std::unique_ptr< SENSCalibration >	_calibration

Detailed Description

Definition at line 8 of file SENSVideoStream.h.

Constructor & Destructor Documentation

SENSVideoStream()

SENSVideoStream::SENSVideoStream	(	const std::string &	videoFileName,
		bool	videoLoops,
		bool	mirrorH,
		bool	mirrorV,
		float	targetFps = 0
	)

Definition at line 8 of file SENSVideoStream.cpp.

  : _videoLoops(videoLoops),
    _mirrorH(mirrorH),
    _mirrorV(mirrorV)
{
    if (!Utils::fileExists(videoFileName))
    {
        throw SENSException(SENSType::VIDEO, "Video file does not exist: " + videoFileName, __LINE__, __FILE__);
    }
 
    _cap.open(videoFileName);
    if (!_cap.isOpened())
        throw SENSException(SENSType::VIDEO, "Could not open video file stream: " + videoFileName, __LINE__, __FILE__);
 
    _videoFrameSize = {(int)_cap.get(cv::CAP_PROP_FRAME_WIDTH), (int)_cap.get(cv::CAP_PROP_FRAME_HEIGHT)};
    _frameCount     = (int)_cap.get(cv::CAP_PROP_FRAME_COUNT);
    _fps            = (float)_cap.get(cv::CAP_PROP_FPS);
 
    if (targetFps == 0)
        _targetFps = _fps;
    else
        _targetFps = targetFps;
 
    _videoFileName = videoFileName;
}

Member Function Documentation

calibration()

const SENSCalibration* const SENSVideoStream::calibration ( ) const

inline

Definition at line 26 of file SENSVideoStream.h.

    {
        return _calibration.get();
    }

fps()

float SENSVideoStream::fps ( ) const

inline

Definition at line 22 of file SENSVideoStream.h.

{ return _fps; }

frameCount()

int SENSVideoStream::frameCount ( ) const

inline

Definition at line 21 of file SENSVideoStream.h.

{ return _frameCount; }

getFrameSize()

cv::Size SENSVideoStream::getFrameSize ( ) const

inline

Definition at line 17 of file SENSVideoStream.h.

{ return _videoFrameSize; }

grabNextFrame()

SENSFramePtr SENSVideoStream::grabNextFrame

(

)

Definition at line 38 of file SENSVideoStream.cpp.

{
    if (!_cap.isOpened())
        throw SENSException(SENSType::VIDEO, "Video file stream is not open!", __LINE__, __FILE__);
 
    if (_videoLoops)
    {
        if (_cap.get(cv::CAP_PROP_POS_FRAMES) == _frameCount)
            _cap.set(cv::CAP_PROP_POS_FRAMES, 0);
    }
 
    SENSFramePtr sensFrame;
    cv::Mat      bgrImg;
    cv::Mat      grayImg;
 
    if (_cap.read(bgrImg))
    {
        SENS::mirrorImage(bgrImg, _mirrorH, _mirrorV);
        cv::cvtColor(bgrImg, grayImg, cv::COLOR_BGR2GRAY);
 
        sensFrame = std::make_unique<SENSFrame>(
          SENSClock::now(),
          bgrImg,
          grayImg,
          _mirrorH,
          _mirrorV,
          1.0f,
          cv::Mat(),
          bgrImg.cols,
          bgrImg.rows);
    }
 
    return sensFrame;
}

grabNextResampledFrame()

SENSFramePtr SENSVideoStream::grabNextResampledFrame

(

)

Definition at line 73 of file SENSVideoStream.cpp.

{
    if (!_cap.isOpened())
        throw SENSException(SENSType::VIDEO, "Video file stream is not open!", __LINE__, __FILE__);
 
    if (_videoLoops)
    {
        if (_cap.get(cv::CAP_PROP_POS_FRAMES) == _frameCount)
            _cap.set(cv::CAP_PROP_POS_FRAMES, 0);
    }
 
    SENSFramePtr sensFrame;
    cv::Mat      bgrImg;
    cv::Mat      grayImg;
 
    float frameDuration = 1.0f / _targetFps;
    int   frameIndex    = (int)_cap.get(cv::CAP_PROP_POS_FRAMES);
    int   skippedFrame  = 0;
    float frameTime;
    float lastFrameTime = frameIndex / _fps;
    do
    {
        skippedFrame++;
        frameTime = (float)(frameIndex + skippedFrame) / _fps;
    } while ((frameTime - lastFrameTime) < frameDuration);
 
    float frameError = (frameTime - lastFrameTime - frameDuration); //Compute overflow
    int   nbFrame    = (int)(frameIndex * _targetFps / _fps);       //Expected number of frames
    float totalError = (nbFrame * frameError);                      //Total cumulated error
    if ((fmod(totalError, frameDuration) + frameError) > frameDuration && skippedFrame > 1)
    {
        skippedFrame--;
    }
 
    moveCapturePosition(skippedFrame);
 
    if (_cap.read(bgrImg))
    {
        SENS::mirrorImage(bgrImg, _mirrorH, _mirrorV);
        cv::cvtColor(bgrImg, grayImg, cv::COLOR_BGR2GRAY);
 
        sensFrame = std::make_unique<SENSFrame>(
          SENSClock::now(),
          bgrImg,
          grayImg,
          _mirrorH,
          _mirrorV,
          1.0,
          cv::Mat(),
          bgrImg.cols,
          bgrImg.rows);
    }
 
    return sensFrame;
}

grabPreviousFrame()

SENSFramePtr SENSVideoStream::grabPreviousFrame

(

)

Definition at line 146 of file SENSVideoStream.cpp.

{
    moveCapturePosition(-2);
    return grabNextFrame();
}

grabPreviousResampledFrame()

SENSFramePtr SENSVideoStream::grabPreviousResampledFrame

(

)

Definition at line 129 of file SENSVideoStream.cpp.

{
    int   frameIndex   = (int)_cap.get(cv::CAP_PROP_POS_FRAMES);
    int   skippedFrame = 0;
    float frameTime;
    float currentFrameTime = frameIndex / _fps;
 
    do
    {
        frameTime = frameIndex - skippedFrame / _fps;
        skippedFrame++;
    } while ((currentFrameTime - frameTime) > 1.0 / _targetFps);
 
    moveCapturePosition(-skippedFrame + 1);
    return grabNextFrame();
}

guessAndSetCalibration()

void SENSVideoStream::guessAndSetCalibration

(

float

fovGuess

)

Definition at line 176 of file SENSVideoStream.cpp.

{
    _calibration = std::make_unique<SENSCalibration>(_videoFrameSize,
                                                     fovGuess,
                                                     false,
                                                     false,
                                                     SENSCameraType::VIDEOFILE,
                                                     Utils::ComputerInfos().get());
}

isOpened()

bool SENSVideoStream::isOpened ( ) const

inline

Definition at line 24 of file SENSVideoStream.h.

{ return _cap.isOpened(); }

moveCapturePosition()

void SENSVideoStream::moveCapturePosition ( int  n )

private

Definition at line 152 of file SENSVideoStream.cpp.

{
    int frameIndex = (int)_cap.get(cv::CAP_PROP_POS_FRAMES);
    frameIndex += n;
 
    if (frameIndex < 0)
        frameIndex = 0;
    else if (frameIndex > _frameCount)
        frameIndex = _frameCount;
 
    _cap.set(cv::CAP_PROP_POS_FRAMES, frameIndex);
}

nextFrameIndex()

int SENSVideoStream::nextFrameIndex ( ) const

inline

Definition at line 20 of file SENSVideoStream.h.

{ return (int)_cap.get(cv::CAP_PROP_POS_FRAMES); }

setCalibration()

void SENSVideoStream::setCalibration	(	SENSCalibration	calibration,
		bool	buildUndistortionMaps
	)

Definition at line 165 of file SENSVideoStream.cpp.

{
    if (!_cap.isOpened())
        throw SENSException(SENSType::CAM, "setCalibration not possible if video stream is not started!", __LINE__, __FILE__);
 
    _calibration = std::make_unique<SENSCalibration>(calibration);
    //now we adapt the calibration to the target size
    if (_videoFrameSize.width != calibration.imageSize().width || _videoFrameSize.height != calibration.imageSize().height)
        _calibration->adaptForNewResolution({_videoFrameSize.width, _videoFrameSize.height}, buildUndistortionMaps);
}

videoFilename()

const std::string& SENSVideoStream::videoFilename ( ) const

inline

Definition at line 19 of file SENSVideoStream.h.

{ return _videoFileName; }

Member Data Documentation

_calibration

std::unique_ptr<SENSCalibration> SENSVideoStream::_calibration

private

Definition at line 49 of file SENSVideoStream.h.

_cap

cv::VideoCapture SENSVideoStream::_cap

private

Definition at line 37 of file SENSVideoStream.h.

_fps

float SENSVideoStream::_fps = 0.f

private

Definition at line 43 of file SENSVideoStream.h.

_frameCount

int SENSVideoStream::_frameCount = 0

private

Definition at line 39 of file SENSVideoStream.h.

_mirrorH

bool SENSVideoStream::_mirrorH = false

private

Definition at line 46 of file SENSVideoStream.h.

_mirrorV

bool SENSVideoStream::_mirrorV = false

private

Definition at line 47 of file SENSVideoStream.h.

_targetFps

float SENSVideoStream::_targetFps

private

Definition at line 44 of file SENSVideoStream.h.

_videoFileName

std::string SENSVideoStream::_videoFileName

private

Definition at line 40 of file SENSVideoStream.h.

_videoFrameSize

cv::Size2i SENSVideoStream::_videoFrameSize

private

Definition at line 38 of file SENSVideoStream.h.

_videoLoops

bool SENSVideoStream::_videoLoops = false

private

Definition at line 42 of file SENSVideoStream.h.

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The documentation for this class was generated from the following files:

• SENSVideoStream.h
• SENSVideoStream.cpp