Exhale (ecodis extended high-efficiency and low-complexity encoder) is a very easy audio encoder that can be used to encode uncompressed WAV audio files into highly compressed MPEG-4 M4A audio files. It is an open-source command line interface (CLI) application but they also offer a GUI that makes it easy to use the application.
As well as the command line interface application is concerned, it is extremely easy to use in itself. You can simply give the command in the following format:
exhale.exe preset-level input.wav output.m4a
where preset-level is a digit from 0 to 9 or a small letter from a to g, input.wav is the input WAV file and the output.m4a is the output MPEG-4 audio file.
If the preset-level is a digit (0-9), then it sets the low-complexity standard compliant xHE-AAC at 16·#+48 kbps. Similarly, if the preset-level is a letter (a-g), then it sets low-complexity compliant xHE-AAC with SBR at 12·#+36 kbps. The output file is MPEG-4 audio and can have an extension of M4A or even MP4.
If you do not like the command line interface application, then they offer a GUI application. The GUI package comes with the CLI version packed inside too. However, it is an older version and you can replace it with the new CLI version downloaded separately from the gitlab page for exhale.
In the Exhale GUI, you can pick one input WAV file or a folder containing many WAV audio files. We can even connect to a Google Drive account that may hold the audio files. In the second step, we have to pick an output folder where the encoded M4A audio files are to be copied. We can then set the preset level and number of CPU cores/threads to be used for encoding. After this we can click on the “Start” button and wait for the encoding to be completed.
Exhale is a standalone MPEG-4 audio conversion program that does not depend on any external libraries or tools. During our tests we found that it compresses the files into M4A even better than the popular FFmpeg project using the default settings.
You can download Exhale audio encoder from https://gitlab.com/ecodis/exhale/-/releases.