converting all the mp4 audio files in a folder to mp3 using ffmpeg

Question

how can I convert all of the mp4 files in a given folder to mp3 using ffmpeg. Almost all of the links I have seen on google is all about converting mp4 video to mp3. I can do this via VLC player but I have got huge collection ~ 1000 mp4 audio files and want this to be done over command line by some script or command. Is it possible to do it via gstreamer?

Yes.Any way I found the way by calling the ffmpeg.exe using a C# code and using Linq and iterating over each file. — Raulp, Jul 20 '16 at 04:14

llogan · Answer 1 · 2016-07-21T16:39:22.313

40

One method is a bash for loop.

For converting only .mp4 files:

mkdir outputs
for f in *.mp4; do ffmpeg -i "$f" -c:a libmp3lame "outputs/${f%.mp4}.mp3"; done

For converting .m4a, .mov, and .flac:

mkdir outputs
for f in *.{m4a,mov,flac}; do ffmpeg -i "$f" -c:a libmp3lame "outputs/${f%.*}.mp3"; done

For converting anything use the "*" wildcard:

mkdir outputs
for f in *; do ffmpeg -i "$f" -c:a libmp3lame "outputs/${f%.*}.mp3"; done

edited Jul 21 '16 at 16:39

answered Jul 20 '16 at 15:42

llogan

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what if I have to extend the above script for more different number of files ( like .m4a,.mov etc) Like I did : FileInfo[] Files = d.GetFiles("*.mp4").Union(d.GetFiles("*.")).ToArray(); . – Raulp Jul 21 '16 at 05:59

score 3 · Accepted Answer · answered Jul 20 '16 at 04:15

FileInfo[] Files = d.GetFiles("*.mp4").Union(d.GetFiles("*.<any other file extension>")).ToArray(); 

foreach (FileInfo file in Files)
            {
               // str = str + ", " + file.Name;
                  builder.Append(Path.GetFileNameWithoutExtension(file.Name));

ProcessStartInfo startInfo = new ProcessStartInfo();
       startInfo.CreateNoWindow = false;
       startInfo.UseShellExecute = false;
       startInfo.FileName = "ffmpeg.exe";
       startInfo.WindowStyle = ProcessWindowStyle.Hidden;
       startInfo.RedirectStandardOutput = !string.IsNullOrEmpty("test");
     startInfo.Arguments = "-i " + filename + ".mp4 -q:a 0 -map a " + filename + ".mp3";

}

converting all the mp4 audio files in a folder to mp3 using ffmpeg

2 Answers2