
Apple Lossless (also known as Apple Lossless Encoder, ALE, or Apple Lossless Audio Codec, ALAC) is an audio codec developed by Apple Inc. for lossless data compression of digital music. Apple Lossless data is stored within an MP4 container with the filename extension .m4a. While Apple Lossless has the same file extension as AAC, it is not a variant of AAC, but uses linear prediction similar to other lossless codecs such as FLAC and Shorten. iPods with a dock connector (not the Shuffle) and recent firmware can play Apple Lossless-encoded files. It does not utilize any digital rights management (DRM) scheme, but by the nature of the container, it is thought that DRM can be applied to ALAC much the same way it can with other files in QuickTime containers.
Because of its exceptional performance and quality, Advanced Audio Coding (AAC) is at the core of the MPEG-4, 3GPP and 3GPP2 specifications and is the audio codec of choice for Internet, wireless and digital broadcast arenas. AAC provides audio encoding that compresses much more efficiently than older formats, such as MP3, yet delivers quality rivaling that of uncompressed CD audio.
So, we are done with the formats and we have to choose which codec to use for M4A. We can still use the same ALAC, but with reduced parameters to save a little disk space. For a significant reduction in file size, we will have to use AAC. Let's consider the latter option as the most popular.
For maximum preservation of sound quality we need an audio converter that supports 32-bit audio. Using regular 16-bit converters reduces the dynamic range of your music and can lead to such unpleasant effects as clipping. One such converter is available on our website.

1 Download Audio Converter Plus
You can download Audio Converter Plus from this site:https://www.abyssmedia.com/downloads/audioconverter.exe
2 Add ALAC Files
Once Audio Converter Plus is installed properly, launch it and click on the "Add File" button on the tool bar. The standard file open dialog appears. Select "ALAC - Apple Lossless" in its "Files of type" combo box. Select the file(s) you want to convert and click "Open". The file will be added to the conversion file list.
3 Select output format
Use the setting panel on the bottom of the window to control the output format. Click on the toggle to the left of the "Format" label to expand the panel. Select "M4A - MPEG-4 Audio" as the "Audio Type".
4 Select output directory
Expand the "Output directory" panel. Use the "Browse" button to select the output directory. Never select the same directory in which the source files are located. Since they have the same name and extension, they will be overwritten. It is better to select a different directory to be able to make a second attempt.
5 Convert
Click the "Convert" button on the toolbar and the conversion task will start immediately. You can minimize the converter window to the background and do other things while the conversion is in progress.