Unable to run command through Java, but can run it through cmd CreateProcess error=2, The system cannot find the file specified

Question

I am unable to convert my mp3s to wavs for easier data manipulation using Java. I can open a command prompt and copy the exact string stored in s when I debug and this will properly create the wav file. The code is below. I was able to use ffmpeg by building strings this way to split up a few mp3s into separate tracks based on a tracklist. I reinstalled Windows 10, so I'm assuming it has something to do with that. Is there a setting I have to change? Why would it run in the command prompt, but not with Java?

package mp3towav;

import java.io.File;
import java.io.IOException;

public class Mp3towav {

    // mp3 folder
    public static final String MP3FOLDER = "C:\\Users\\Al\\Documents\\Sounds\\PokemonOST\\YellowOST\\MP3";

    public static void main(String[] args) throws IOException {

        // Gets the mp3 files and converts them to wav
        File mp3folder = new File(MP3FOLDER);

        String[] mp3s = mp3folder.list();

        File f;

        String s; 

        for(int i = 0; i < mp3s.length; i++) {
            f = new File(mp3s[i]);
            s = ("ffmpeg -i " + MP3FOLDER + "\\" + f.getName() + " " + (MP3FOLDER + "\\" + f.getName()).replaceAll("MP3", "WAV").replaceAll("mp3", "wav"));
            Runtime.getRuntime().exec(s);
            System.out.println("test");
        }



    }

}

Edit:

So I never got Java to use PATH, but added in the absolute path to the ffmpeg executable in Java.

Answer 1

I had to add the path to the ffmpeg bin including the file name ffmpeg.exe instead of having Java rely on the PATH variable in windows even though ffmpeg works correctly in the CMD window.