Saving .mp4 audio file as an mp3 file

Question

If you were to save a .jpeg image as an .png image by simply changing the file extension, the image will successfully convert itself.

Is there a way similar to this where I can save an .mp4 audio file as an .mp3 file by simply changing the file extension? I know you can save it as an .mp4 file then use iTunes/converting program to convert it into an .mp3 file, but I was hoping that there might be a simpler way.

Answer 1

The answer is no it is not possible

First let me point out where your mistake comes from. When you are renaming .jpg to .png the file does not get converted. You can check it with comp command or with any available hex viewer. In fact, nothing changes apart from the filename. When you are then trying to open that file it is still opened with the same editor/viewer simply because your OS is set up to use the same program for both .jpg and .png files. And it still opens correctly becaue the program itself does not use extension to determine the file type. Most editors/viewers use the first line of the file (or first X characters) to determine the type.

With .mp4 and .mp3 it does not happen because .mp4 is a combined audio/video format and .mp3 is purely audio and most likely you are using different applications to open the two. There might be some other reasons here too, but the most important one is that it is not supposed to work in the first place.

Anyway, I recommend you stop trying to achieve that behavior because one does not simply convert the file by renaming it. I would recommend getting a decent converter (or keep using iTunes) and also reading some background info on following subjects:

• MP4
• MP3
• Mime types