// 上传之后的视频文件名为test.tmpmedia
String command = "mencoder test.tmpmedia -o test.flv -ofps 25 -of lavf -oac mp3lame -srate 22050 -ovc lavc -lavcopts "
                + "vcodec=flv:keyint=59:vbitrate=6000:mbd=2:trell:v4mv:o=mpv_flagg=cbp_rd:last_pred=3 -vf harddup,scale=480:256";

Process p = Runtime.getRuntime().exec(command);

// 读取命令的输出信息
InputStream is = p.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
p.waitFor();
if (p.exitValue() != 0) {
    //说明命令执行失败
    //可以进入到错误处理步骤中
}

// 打印输出信息
String s = null;
while ((s = reader.readLine()) != null) {
    System.out.println(s);
}

// 将命令分解为List存储
String[] commandSplit = command.split(" ");
List<String> lcommand = new ArrayList<String>();
for (int i = 0; i < commandSplit.length; i++) {
    lcommand.add(commandSplit[i]);
}

ProcessBuilder processBuilder = new ProcessBuilder(lcommand);
processBuilder.redirectErrorStream(true);
Process p = processBuilder.start();
InputStream is = p.getInputStream();
BufferedReader bs = new BufferedReader(new InputStreamReader(is));

p.waitFor();
if (p.exitValue() != 0) {
    //说明命令执行失败
    //可以进入到错误处理步骤中
}
String line = null;
while ((line = bs.readLine()) != null) {
    System.out.println(line);
    resultLog += line;
}