java 调用ffmpeg执行dos命令

import java.io.File;

import java.io.IOException;



public class TestMencoder {

	

	public static void main(String[] args) {

		

		String cmd2="cmd /c start "+"D:\\MPlayer\\mencoder "+"E:\\478.rmvb"+" -o "+"E:\\478_mencoder.flv"+" -of lavf -oac lavc -vf pullup,pp=md -ovc lavc -lavcopts vcodec=flv:vbitrate=528:mbd=2:mv0:trell:v4mv:cbp:last_pred=3:acodec=libmp3lame:abitrate=56 -srate 22050 -ofps 15 ";

		String cmd=" D:\\foresee\\workspace3.2\\rr\\ffmpeg\\ffmpeg.exe -i"+" e:\\74.2.mpg"+" -y -ab 32 -ar 11025 -b 400000 -s 320*240 "+"e:\\74.2_bat.flv ";

		try {

			Process pr=Runtime.getRuntime().exec(cmd2);

			

			pr.getInputStream();

			System.out.println(cmd);

		} catch (IOException e) {

			// TODO Auto-generated catch block

			e.printStackTrace();

		}

	}



}

D:\\MPlayer\\mencoder是mencoder.exe的文件路径

D:\\foresee\\workspace3.2\\rr\\ffmpeg\\是ffmpeg.exe的文件路径

在出现说ffmpeg不是外部执行命令时已经这个没有写对的原因了