ffmpeg视频裁剪

**需要注意，ffmpeg 命令 -s 指定了宽高后，如果为奇数宽高（101*101）,则裁剪后的视频无法正常播放，不加-s则ffmpeg自动-1处理；**
 private void cutVideo() throws Exception{
    try {
        String ffmpegSource ="/opt/xxxxx/ffmpeg/ffmpeg";// todo ffmpeg程序绝对路径
        String videoSource = "/opt/xxxxxx/xxx_source.mp4"; //todo  视频源绝对路径
        String videoTarget = "/opt/xxxxxx/xxx_target.mp4"; // todo 视频目标绝对路径
        //执行程序拼接命令
        List<String> command = new ArrayList<>();
        command.add(ffmpegSource);
        command.add("-i");
        command.add(videoSource);
        command.add("-vf");
        int cutVideoWidth = 100;  // todo 要裁的实际宽
        int cutVideoHeight = 100; // todo 要裁的实际高
        int leftTopX = 0; //todo 要裁的部分左上角x坐标
        int leftTopY = 0; //todo 要裁的部分左上角y坐标
        StringBuffer tmp = new StringBuffer();
        tmp.append("crop=w=");
        tmp.append(cutVideoWidth);
        tmp.append(":h=");
        tmp.append(cutVideoHeight);
        tmp.append(":x=");
        tmp.append(leftTopX);
        tmp.append(":y=");
        tmp.append(leftTopY);
        String vfStr = tmp.toString();
        command.add("-vf");
        command.add(vfStr);
        command.add("-r");
        command.add("25");
        command.add("-y");
        command.add("-s");
        String sStr = cutVideoWidth + "*" + cutVideoHeight;
        command.add(sStr);
        command.add(videoTarget);
        ProcessBuilder builder = new ProcessBuilder();
        builder.command(command);
        builder.redirectErrorStream(true);
        Process p = builder.start();
        BufferedReader reader = null;
        reader = new BufferedReader(new InputStreamReader(p.getInputStream()));
        String line = null;
        StringBuffer message = new StringBuffer();
        while ((line = reader.readLine()) != null) {
            // ffmpeg 返回信息拼接字符串
            message.append(line.trim() + "\r\n");
            continue;
        }
        p.waitFor();
        System.out.println(message.toString().trim());
        if (reader != null) {
            reader.close();
        }
        p.destroy();
    }catch (Exception e){
        e.printStackTrace();
        // message 就是 ffmpeg报出来的错误信息

    }
}