WinFF gives a frontend to FFmpeg. It (really FFmpeg) can be used for batch conversion of audio and video recordsdata. Simply add the file(s) you wish to convert, choose the specified format, apply device presets if you want. You can get all geeky and learn the command line switches or you may attempt WinFF. It [...]
For Mac, you may also apply the drag and drop process, or you may go to File" then click on Load Media Recordsdata", browse for the MP3 file and add it to this system. To import the MP3 files, you should use either the drag and drop technique, or you possibly can click the Add [...]
iConverter is a free mobile app for iPhone and iPad It has a wide variety of audio input and output file sorts in addition to its exhaustive list of supported doc and video file sorts. This conversion app works seamlessly with the File app and permits you to drag and drop recordsdata in split-screen duties. [...]