CFFMPEG_InputStream.h

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/* +---------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)               |
   |                          http://www.mrpt.org/                             |
   |                                                                           |
   | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file        |
   | See: http://www.mrpt.org/Authors - All rights reserved.                   |
   | Released under BSD License. See details in http://www.mrpt.org/License    |
   +---------------------------------------------------------------------------+ */

#ifndef  CFFMPEG_InputStream_H
#define  CFFMPEG_InputStream_H

#include <mrpt/utils/utils_defs.h>
#include <mrpt/utils/CImage.h>
#include <mrpt/utils/safe_pointers.h>

#include <mrpt/hwdrivers/link_pragmas.h>


/*---------------------------------------------------------------
        Class
  ---------------------------------------------------------------*/
namespace mrpt
{
        namespace hwdrivers
        {
                /** A generic class which process a video file or other kind of input stream (http, rtsp) and allows the extraction of images frame by frame.
                  *  Video sources can be open with "openURL", which can manage both video files and "rtsp://" sources (IP cameras).
                  *
                  *  Frames are retrieved by calling CFFMPEG_InputStream::retrieveFrame
                  *
                  *   For an example of usage, see the file "samples/grab_camera_ffmpeg"
                  *
                  * \note This class is an easy to use C++ wrapper for ffmpeg libraries (libavcodec). In Unix systems these libraries must be installed in the system as explained in <a href="http://www.mrpt.org/Building_and_Installing_Instructions" > MRPT's wiki</a>. In Win32, a precompiled version for Visual Studio must be also downloaded as explained in <a href="http://www.mrpt.org/Building_and_Installing_Instructions" >the wiki</a>.
                  * \ingroup mrpt_hwdrivers_grp
                  */
                class HWDRIVERS_IMPEXP CFFMPEG_InputStream
                {
                private:
                        mrpt::utils::void_ptr_noncopy   m_state;        //!< The internal ffmpeg state
                        std::string  m_url;     //!< The open URL
                        bool  m_grab_as_grayscale;

                public:
                        CFFMPEG_InputStream();                          //!< Default constructor, does not open any video source at startup
                        virtual ~CFFMPEG_InputStream();         //!< Destructor

                        /** Open a video file or a video stream (rtsp://)
                          *  This can be used to open local video files (eg. "myVideo.avi", "c:\a.mpeg") and also IP cameras (e. "rtsp://a.b.c.d/live.sdp").
                          *  However, note that there is currently no support for user/password in IP access.
                          *  If verbose is set to true, more information about the video will be dumped to cout.
                          *
                          * \sa close, retrieveFrame
                          * \return false on any error (and error info dumped to cerr), true on success.
                          */
                        bool openURL( const std::string &url, bool grab_as_grayscale = false, bool verbose = false );

                        bool isOpen() const;    //!< Return whether the video source was open correctly

                        /** Close the video stream (this is called automatically at destruction).
                          * \sa openURL
                          */
                        void close();

                        double getVideoFPS() const;     //!< Get the frame-per-second (FPS) of the video source, or "-1" if the video is not open.

                        /** Get the next frame from the video stream.
                          *  Note that for remote streams (IP cameras) this method may block until enough information is read to generate a new frame.
                          *  Images are returned as 8-bit depth grayscale if "grab_as_grayscale" is true.
                          *  \return false on any error, true on success.
                          *  \sa openURL, close, isOpen
                          */
                        bool retrieveFrame( mrpt::utils::CImage &out_img );


                };

        }
}


#endif