動画ファイルの表示

#include<cv.h>
#include<highgui.h>

using namespace cv;

int main (int argc, char **argv)
{
  double width;  // 幅
  double height; // 高さ
  double fps; // フレームレート
  double msec; // 現在位置
  double index = -1; // フレームのインデックス
  double ratio; // 相対位置

  CvCapture *capture = NULL;
  IplImage *frame = 0;
  double prev_index; 
  int ch;

  // 幅と高さの取得
  capture = cvCaptureFromFile("/usr/local/share/opencv/samples/c/tree.avi");
  width = cvGetCaptureProperty (capture, CV_CAP_PROP_FRAME_WIDTH);
  height = cvGetCaptureProperty (capture, CV_CAP_PROP_FRAME_HEIGHT);
  fps = cvGetCaptureProperty (capture, CV_CAP_PROP_FPS);

  namedWindow ("VideoFile", CV_WINDOW_AUTOSIZE | CV_WINDOW_FREERATIO);

  while (1) {
    frame = cvQueryFrame (capture);

    msec = cvGetCaptureProperty (capture, CV_CAP_PROP_POS_MSEC);
    prev_index = index; 
    index = cvGetCaptureProperty (capture, CV_CAP_PROP_POS_FRAMES);
    ratio = cvGetCaptureProperty (capture, CV_CAP_PROP_POS_AVI_RATIO);

    cvShowImage ("VideoFile", frame);
    ch = cvWaitKey ( 1000.0 / fps ); // 0 はディレイ時間 (ミリ秒単位)
    if (ch == '\x1b') {
      // ESC キー
      break;
    }
    fprintf( stderr, "width = %f, height = %f, fps = %f, index = %f, msec = %f\n", width, height, fps, index, msec );
    // 終わりまで来たら最初に戻る
    if ( prev_index == index ) {
      cvSetCaptureProperty (capture, CV_CAP_PROP_POS_AVI_RATIO, 0.0);
    }

  }

  cvReleaseCapture (&capture);
  cvDestroyWindow ("VideoFile");

  return 0;
}