// *****************************************************************
// Delphi-OpenCV Demo
// Copyright (C) 2013 Project Delphi-OpenCV
// ****************************************************************
// Contributor:
  // Laentir Valetov
// email:laex@bk.ru
// ****************************************************************
// You may retrieve the latest version of this file at the GitHub,
// located at git://github.com/Laex/Delphi-OpenCV.git
// ****************************************************************
// The contents of this file are used with permission, subject to
// the Mozilla Public License Version 1.1 (the "License"); you may
// not use this file except in compliance with the License. You may
// obtain a copy of the License at
// http://www.mozilla.org/MPL/MPL-1_1Final.html
//
// Software distributed under the License is distributed on an
// "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
// implied. See the License for the specific language governing
// rights and limitations under the License.
// ******************************************************************

program IPCamVideoCapture;

uses
  System.SysUtils,
  ocv.highgui_c,
  ocv.core_c,
  ocv.core.types_c,
  ocv.imgproc_c,
  ocv.imgproc.types_c;

const
  // See http://www.ispyconnect.com
  VIDEO_FILE_NAME = 'rtsp://192.168.0.202:554/cam/realmonitor?channel=1&subtype=0&unicast=true&proto=Onvif';
  //'rtsp://192.168.0.200:554/mpeg4';
  // declare escape char
  ESCAPE_CHAR = 27;

var
  // declate an opencv video file capture object, users can use this object to
  // interact with the video file, get/set properties and also grab video frames
  capture: pCVCapture;
  // declare an opencv image pointer variable
  frame: pIplImage;
  // declate a key variable to get user key pressed
  key: integer;

begin
  try
    // create capture object for specific video filename
    capture := cvCreateFileCapture(VIDEO_FILE_NAME);
    // check if capture assigned, if not then it means that opencv can not open
    // the requested file, opencv uses VFW to open the files so some file formats
    // are not fully supported (can be enhence with FFMPEG support but this is
    // beyond our scope right now
    if Assigned(capture) then
    begin
      // create display window
      cvNamedWindow('video');
      // reset user key pressed
      key := 0;
      // loop while user didn't press ESCAPE
      while key <> ESCAPE_CHAR do
      begin
        // start grabbing frames, single frame at a time, this method is a
        // combination of two methods one grab frame and the other advances to the
        // next frame
        //
        // REMARK: do not (!!!) release "frame" object since it is used internally
        // by the capture object is its memory is release when the "capture" object
        // is being destroyed
        frame := cvQueryFrame(capture);
        // check if frame is valid, when you reach end-of-file "frame" object
        // starts to be NIL (since the method advances to the next frame each time
        // is is called...)
        if Assigned(frame) then
          // show frame in window
          cvShowImage(
            'video',
            frame);
        // wait for user key, delay is in msec so 1000msec = 1sec wait period
        key := cvWaitKey(10);
      end;
      // destroy display windows
      cvDestroyAllWindows;
      // release "capture" object and its related memory
      cvReleaseCapture(capture);
    end;
  except
    on E: Exception do
      Writeln(
        E.ClassName,
        ': ',
        E.Message);
  end;

end.