//This file depends on ffmpeg.
//Linux users: apt-get install ffmpeg
//Windows users: see http://ffmpeg.zeranoe.com/builds/
//Put the first argument (file path) in "quotes" if it has spaces or the program will return an exception
import java.io.*;
import java.util.Scanner;

public class ffmpeg{
    public static String _videopath = "../recording.avi";
    public static String _r = "1"; //_r is the number of frames per second that ffmpeg should grab
    public static String ffmpegpath = "C:\fmpeg\bin\ffmpeg.exe";
    static StringBuffer command = new StringBuffer();
    static Scanner input = new Scanner(System.in);
        public static void main(String args[]){

            //this segment of code identifies the operating system and generates the ffmpeg path
            if(System.getProperty("os.name").startsWith("Windows")){
                System.out.println("Please enter the path to ffmpeg on your Windows system: ");
                ffmpegpath = input.nextLine();
                try{
                    File testffmpeg = new File(ffmpegpath + "\\ffmpeg.exe");
                    if(!testffmpeg.exists()){
                        throw new Exception("ffmpeg could not be found at the specified path.");
                    }
                }catch(Exception ex){
                    System.err.print(ex.getMessage());
                }
            }else{
                ffmpegpath = "ffmpeg";
            }

            //check the command-line arguments for any commands
            switch(args.length){
                case 1:
                    _videopath=args[0];
                    break;
                case 2:
                    _videopath=args[0];
                    _r=args[1];
                    break;
                default:
            }

            //this segment of code checks if the file exists and gives us the directory it's in if it does
            try{
                File testVideo = new File(_videopath);
                if(!testVideo.exists()){
                    throw new Exception("File '" + _videopath + "' does not exist.");
                }
            }catch(Exception ex){
                System.err.print(ex.getMessage());
            }

            //setup originalframes-recording directory, where recording is the video name minus its extension
            File testVideo = new File(_videopath);
            File _rootpath = new File(testVideo.getParent());
            String _videoname = testVideo.getName();
            _videoname = _videoname.substring(0, _videoname.lastIndexOf("."));
            File _originalframespath = new File(_rootpath.getAbsolutePath()+"/originalframes-"+_videoname);
            try{
                if(_rootpath.exists()){
                    if(!_originalframespath.exists())
                        _originalframespath.mkdir();
                }else
                    throw new Exception("Directory '" + _rootpath.getAbsolutePath() + "' does not exist.");
            }catch(Exception ex){
                System.err.print(ex.getMessage());
            }

            //build ffmpeg command
            String commandStr[] = {ffmpegpath,"-i",_videopath,"-r", _r,"-f","image2",_originalframespath.getAbsolutePath()+"/%03d.jpg"};

            //print the command to execute
            for(String x:commandStr){
                System.out.print(x+" ");
            }

            //execute ffmpeg with the command generated by the previous segment
            try{
                Process ffmpeg = Runtime.getRuntime().exec(commandStr);//THIS DOES NOT WORK
                BufferedReader in = new BufferedReader(new InputStreamReader(ffmpeg.getInputStream()));
                String line = null;
                while((line = in.readLine())!= null){
                    System.out.println(line);
                }
            }catch(IOException ex){
                ex.printStackTrace();
            }
        }
}