#include <vpVideoWriter.h>

Public Member Functions
	vpVideoWriter ()

	~vpVideoWriter ()

void	close ()

unsigned int	getCurrentFrameIndex () const

void	open (vpImage< vpRGBa > &I)

void	open (vpImage< unsigned char > &I)

void	resetFrameCounter ()

void	saveFrame (vpImage< vpRGBa > &I)

void	saveFrame (vpImage< unsigned char > &I)

void	setBitRate (const unsigned int bitrate)

void	setCodec (const AVCodecID codec_id)

void	setFileName (const char *filename)

void	setFileName (const std::string &filename)

void	setFirstFrameIndex (const unsigned int first_frame)

void	setFramerate (const int frame_rate)

Detailed Description

Class that enables to write easily a video file or a sequence of images.

The following example shows how this class is really easy to use. It enable to write an image sequence. The images are stored in the folder "./image" and are named "image0000.jpeg", "image0001.jpeg", "image0002.jpeg", ...

#include <visp/vpConfig.h>
#include <visp/vpVideoWriter.h>
int main()
{
vpImage<vpRGBa> I;
vpVideoWriter writer;
//Initialize the writer.
writer.setFileName("./image/image%04d.jpeg");
writer.open(I);
for ( ; ; )
{
  //Here the code to capture or create an image and stores it in I.
  //Save the image
  writer.saveFrame(I);
}
writer.close();
return 0;
}

The other following example explains how to use the class to write directly an mpeg file.

#include <visp/vpVideoWriter.h>
int main()
{
#ifdef VISP_HAVE_FFMPEG
  vpImage<vpRGBa> I;
  vpVideoWriter writer;
  // Set up the framerate to 30Hz. Default is 25Hz.
  writer.setFramerate(30);
  // Set up the bit rate
  writer.setBitRate(1000000);
  // Set up the codec to use
#if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(54,51,110) // libavcodec 54.51.100
  writer.setCodec(CODEC_ID_MPEG2VIDEO);
#else
  writer.setCodec(AV_CODEC_ID_MPEG2VIDEO);
#endif
  writer.setFileName("./test.mpeg");
  writer.open(I);
  for ( ; ; )
  {
    // Here the code to capture or create an image and store it in I.
    // Save the image
    writer.saveFrame(I);
  }
  writer.close();
  return 0;
#endif
}

Examples:: tutorial-grabber-1394-writer.cpp.

Definition at line 135 of file vpVideoWriter.h.

Constructor & Destructor Documentation

vpVideoWriter::vpVideoWriter ( )

Basic constructor.

Definition at line 54 of file vpVideoWriter.cpp.

vpVideoWriter::~vpVideoWriter ( )

Basic destructor.

Definition at line 90 of file vpVideoWriter.cpp.

Member Function Documentation

void vpVideoWriter::close ( )

Deallocates parameters use to write the video or the image sequence.

Examples:: tutorial-grabber-1394-writer.cpp.

Definition at line 316 of file vpVideoWriter.cpp.

References vpFFMPEG::endWrite(), vpException::notInitialized, and vpERROR_TRACE.

unsigned int vpVideoWriter::getCurrentFrameIndex ( ) const

inline

Gets the current frame index.

Returns: Returns the current frame index.

Definition at line 197 of file vpVideoWriter.h.

void vpVideoWriter::open ( vpImage< vpRGBa > & I )

Sets all the parameters needed to write the video or the image sequence.

Parameters

I	: One image with the right dimensions.

Examples:: tutorial-grabber-1394-writer.cpp.

Definition at line 143 of file vpVideoWriter.cpp.

References vpException::fatalError, vpImage< Type >::getHeight(), vpImage< Type >::getWidth(), vpException::ioError, vpImageException::noFileNameError, vpFFMPEG::openEncoder(), vpFFMPEG::setBitRate(), vpFFMPEG::setFramerate(), and vpERROR_TRACE.

void vpVideoWriter::open ( vpImage< unsigned char > & I )

Sets all the parameters needed to write the video or the image sequence.

Parameters

I	: One image with the right dimensions.

Definition at line 192 of file vpVideoWriter.cpp.

References vpException::fatalError, vpImage< Type >::getHeight(), vpImage< Type >::getWidth(), vpException::ioError, vpImageException::noFileNameError, vpFFMPEG::openEncoder(), vpFFMPEG::setBitRate(), vpFFMPEG::setFramerate(), and vpERROR_TRACE.

void vpVideoWriter::resetFrameCounter ( )

inline

Reset the frame counter and sets it to the first image index.

By default the first frame index is set to 0.

Definition at line 206 of file vpVideoWriter.h.

void vpVideoWriter::saveFrame ( vpImage< vpRGBa > & I )

Saves the image as a frame of the video or as an image belonging to the image sequence.

Each time this method is used, the frame counter is incremented and thus the file name change for the case of an image sequence.

Parameters

I	: The image which has to be saved

Examples:: tutorial-grabber-1394-writer.cpp.

Definition at line 243 of file vpVideoWriter.cpp.

References vpException::notInitialized, vpFFMPEG::saveFrame(), vpERROR_TRACE, and vpImageIo::write().

void vpVideoWriter::saveFrame ( vpImage< unsigned char > & I )

Saves the image as a frame of the video or as an image belonging to the image sequence.

Each time this method is used, the frame counter is incremented and thus the file name change for the case of an image sequence.

Parameters

I	: The image which has to be saved

Definition at line 282 of file vpVideoWriter.cpp.

References vpException::notInitialized, vpFFMPEG::saveFrame(), vpERROR_TRACE, and vpImageIo::write().

void vpVideoWriter::setBitRate ( const unsigned int bitrate )

inline

Sets the bit rate of the video when encoding.

Parameters

bitrate : the expected bit rate.

By default the bit rate is set to 500 000.

Definition at line 219 of file vpVideoWriter.h.

void vpVideoWriter::setCodec ( const AVCodecID codec_id )

inline

Sets the codec used to encode the video.

Parameters

codec_id : the expected codec.

By default codec is set to AV_CODEC_ID_MPEG1VIDEO. But if installed, you can use one of the AVCodecID proposed by ffmpeg such as : AV_CODEC_ID_MPEG2VIDEO, AV_CODEC_ID_MPEG2VIDEO_XVMC, AV_CODEC_ID_MPEG4, AV_CODEC_ID_H264, ... (More AVCodecID can be found in the ffmpeg documentation).

Of course to use the codec it must be installed on your computer.

Definition at line 235 of file vpVideoWriter.h.

void vpVideoWriter::setFileName ( const char * filename )

It enables to set the path and the name of the files which will be saved.

If you want to write a sequence of images, $ filename $ corresponds to the path followed by the image name template. For exemple, if you want to write different images named image0001.jpeg, image0002.jpg, ... and located in the folder /local/image, will be "/local/image/image%04d.jpg".

Parameters

filename : filename template of an image sequence.

Examples:: tutorial-grabber-1394-writer.cpp.

Definition at line 106 of file vpVideoWriter.cpp.

References vpException::memoryAllocationError, vpImageException::noFileNameError, and vpERROR_TRACE.

Referenced by setFileName().

void vpVideoWriter::setFileName ( const std::string & filename )

It enables to set the path and the name of the files which will be saved.

If you want to write a sequence of images, $ filename $ corresponds to the path followed by the image name template. For exemple, if you want to write different images named image0001.jpeg, image0002.jpg, ... and located in the folder /local/image, will be "/local/image/image%04d.jpg".

Parameters

filename : filename template of an image sequence.

Definition at line 133 of file vpVideoWriter.cpp.

References setFileName().

void vpVideoWriter::setFirstFrameIndex ( const unsigned int first_frame )

inline

Enables to set the first frame index.

Parameters

first_frame : The first frame index.

Definition at line 246 of file vpVideoWriter.h.

void vpVideoWriter::setFramerate ( const int frame_rate )

inline

Sets the framerate in Hz of the video when encoding.

Parameters

frame_rate : the expected framerate.

By default the framerate is set to 25Hz.

Definition at line 255 of file vpVideoWriter.h.

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation