LAME is the go-to MP3 encoder in the open-source industry, valued for its extensive features and professional performance. It is widely used in various programming languages and tools, including FFmpeg, Python, Rust, Java, Go, and JavaScript. However, implementing an MP3 encoder from scratch can be challenging due to the lack of an official standard and hidden knowledge behind paywalls. The encoding algorithm itself is complex, involving psychoacoustic models that analyze and discard parts of the audio that humans can’t hear. To find an alternative to LAME, the author discovered Shine, an open-source, featureless, and readable MP3 encoder with a fixed-point math implementation. By porting Shine from C to Go, the author successfully created a Go library for encoding MP3 files.
https://braheezy.github.io/posts/what-i-learned-about-mp3-encoding/