JavaCV获取视频文件时长的方法

package com.duoduo.javacv.samples;

import static com.googlecode.javacv.cpp.opencv_highgui.CV_CAP_PROP_FPS;
import static com.googlecode.javacv.cpp.opencv_highgui.CV_CAP_PROP_FRAME_COUNT;
import static com.googlecode.javacv.cpp.opencv_highgui.cvCreateFileCapture;
import static com.googlecode.javacv.cpp.opencv_highgui.cvGetCaptureProperty;
import static com.googlecode.javacv.cpp.opencv_highgui.cvReleaseCapture;

import java.io.File;

import com.googlecode.javacv.cpp.opencv_highgui.CvCapture;

/**
 * 获取视频时长
 * 
 * @author chengesheng
 * @date 2013-5-22 下午11:15:25
 * @note VideoFileLength
 */
public final class VideoFileLength {

 public static void main(String[] argus) {
 float len = getVideoFileLength("D:/J2EE/kdvp/webrtc/webapp/images/bike.avi");
 System.out.println("Video length: " + len + " s");
 }

 public static float getVideoFileLength(String fileName) {
 File file = new File(fileName);
 if (!file.exists()) {
  return 0;
 }

 float len = 0;
 CvCapture capture = cvCreateFileCapture(fileName);
 try {
  // 获取视频总帧数
  long frameCount =(long) cvGetCaptureProperty(capture, CV_CAP_PROP_FRAME_COUNT);
  // 获取视频每秒帧数
  long fps =(long) cvGetCaptureProperty(capture, CV_CAP_PROP_FPS);

  len = (float) frameCount / fps;
 } catch (Exception e) {
  e.printStackTrace();
 } finally {
  cvReleaseCapture(capture);
 }
 return len;
 }
}