LL2MP4 can convert APE, MP3, FLAC, WAV files to AAC, including tags. Multiple AAC files may be wrapped into one MP4.
Generally this AAC format has the alternative extension M4A. Among others MP4/M4A is a container format, used here to package several AAC files.
This application makes the conversion to MP4 easy. Just drop the files or directories on the application, select a encoding bitrate. Also, decide whether or not the audio files should be wrapped together into one MP4 file, and whether or not the MP4 files should be saved to the source directory. Then start the conversion.
Features:
1. Transfers ID3 tags
If ID3v1 or ID3v2 tags are present in a FLAC, APE or MP3 file, these are transferred to the MP4 file.

2. Drag-and-drop interface
Drop any combination of files of the four supported types on the application. Press CONVERT to start the conversion. You can also drop a folder files on the application. Only files in the top directory are processed. You may drop multiple times. Then, depending on the conversion mode (4.) and save mode (5.) you first have to select a filename and a directory to which the MP4 will be saved.

3. Uses free codecs
Six free codecs are used, and one auxiliary program (Sleep.exe: the application is present in the zip, together with LL2MP4). The actual conversions are performed by existing programs (codecs) which are available free of cost.

4. Two conversion modes are available:
- All the input files are converted together to one MP4 file. MP4 is a wrapper format that can contain multiple 'tracks'.
- All the input files are converted to separate MP4 files; these contain therefore just one 'track'.

5. You can choose between saving the results to a directory of your choice or to the source directory.
If you have selected the option to combine all the AAC files into one MP4 file, you always should supply a filename.

6. The encoding options are limited in this preliminary version to several constant bitrate values. In future there will be more options.

The license of this software is Freeware, you can free download and free use this audio converter software.