java調用ffmpeg獲取視頻時長

public static void main(String[] args) {

    String result =    processFLV("E:\\test\\京視傳媒\\體育類\\xiao.flv");
   
   
    PatternCompiler compiler =new Perl5Compiler();
    try {
        String regexDuration ="Duration: (.*?), start: (.*?), bitrate: (\\d*) kb\\/s";
        String regexVideo ="Video: (.*?), (.*?), (.*?)[,\\s]";
        String regexAudio ="Audio: (\\w*), (\\d*) Hz";
   
        Pattern patternDuration = compiler.compile(regexDuration,Perl5Compiler.CASE_INSENSITIVE_MASK);
        PatternMatcher matcherDuration = new Perl5Matcher();
        if(matcherDuration.contains(result, patternDuration)){
            MatchResult re = matcherDuration.getMatch();

            System.out.println("提取出播放時間  ===" +re.group(1));
            System.out.println("開始時間        =====" +re.group(2));
            System.out.println("bitrate 碼率 單位 kb==" +re.group(3));
        }
       
        Pattern patternVideo = compiler.compile(regexVideo,Perl5Compiler.CASE_INSENSITIVE_MASK);
        PatternMatcher matcherVideo = new Perl5Matcher();
       
        if(matcherVideo.contains(result, patternVideo)){
            MatchResult re = matcherVideo.getMatch();
            System.out.println("編碼格式  ===" +re.group(1));
            System.out.println("視頻格式 ===" +re.group(2));
            System.out.println(" 分辨率  == =" +re.group(3));
        }
       
        Pattern patternAudio = compiler.compile(regexAudio,Perl5Compiler.CASE_INSENSITIVE_MASK);
        PatternMatcher matcherAudio = new Perl5Matcher();
       
        if(matcherAudio.contains(result, patternAudio)){
            MatchResult re = matcherAudio.getMatch();
            System.out.println("音頻編碼             ===" +re.group(1));
            System.out.println("音頻採樣頻率  ===" +re.group(2));
        }

    } catch (MalformedPatternException e) {
        e.printStackTrace();
    }

    }
   

//  ffmpeg能解析的格式：（asx，asf，mpg，wmv，3gp，mp4，mov，avi，flv等）
    private static String processFLV(String inputPath) {
/*
      if (!checkfile(inputPath)){
          _log.warn(inputPath+" is not file");
          return false;
         }
*/
        List<String> commend=new java.util.ArrayList<String>();
       
//        commend.add("e:\\videoconver\\ffmpeg\\ffmpeg ");//可以設置環境變量從而省去這行
       commend.add("ffmpeg");
        commend.add("-i");
        commend.add(inputPath);
      
        try {

            ProcessBuilder builder = new ProcessBuilder();
            builder.command(commend);
            builder.redirectErrorStream(true);
            Process p= builder.start();

           //1. start
            BufferedReader buf = null; // 保存ffmpeg的輸出結果流
            String line = null;
          //read the standard output

            buf = new BufferedReader(new InputStreamReader(p.getInputStream()));
           
            StringBuffer sb= new StringBuffer();
            while ((line = buf.readLine()) != null) {
             System.out.println(line);
             sb.append(line);
             continue;
                 }
            int ret = p.waitFor();//這裏線程阻塞，將等待外部轉換進程運行成功運行結束後，才往下執行
            //1. end
            return sb.toString();
        } catch (Exception e) {
//            System.out.println(e);
            return null;
        }
    }