bliss-rs/README.md

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# bliss music analyser - Rust version
bliss-rs is the Rust improvement of [bliss](https://github.com/Polochon-street/bliss), a
library used to make playlists by analyzing songs, and computing distance between them.

Like bliss, it eases the creation of « intelligent » playlists and/or continuous
play, à la Spotify/Grooveshark Radio, as well as easing creating plug-ins for
existing audio players. For instance, you can use it to make calm playlists
to help you sleeping, fast playlists to get you started during the day, etc.

For now (and if you're looking for an easy-to use smooth play experience),
[blissify](https://crates.io/crates/blissify) implements bliss for
[MPD](https://www.musicpd.org/).

There are also [python](https://pypi.org/project/bliss-audio/) bindings.

Note 1: the features bliss-rs outputs is not compatible with the ones
used by C-bliss, since it uses
different, more accurate values, based on
[actual literature](https://lelele.io/thesis.pdf). It is also faster.

## Examples
For simple analysis / distance computing, a look at `examples/distance.rs` and
`examples/analyse.rs`.

Ready to use examples:

### Compute the distance between two songs
```
use bliss_audio::{BlissError, Song};

fn main() -> Result<(), BlissError> {
    let song1 = Song::new("/path/to/song1")?;
    let song2 = Song::new("/path/to/song2")?;
        
    println!("Distance between song1 and song2 is {}", song1.distance(&song2));
    Ok(())
}
```

### Make a playlist from a song
```
use bliss_audio::{BlissError, Song};
use noisy_float::prelude::n32;

fn main() -> Result<(), BlissError> {
    let paths = vec!["/path/to/song1", "/path/to/song2", "/path/to/song3"];
    let mut songs: Vec<Song> = paths
        .iter()
        .map(|path| Song::new(path))
        .collect::<Result<Vec<Song>, BlissError>>()?;

    // Assuming there is a first song
    let first_song = songs.first().unwrap().to_owned();

    songs.sort_by_cached_key(|song| n32(first_song.distance(&song)));
    println!(
        "Playlist is: {:?}",
        songs
            .iter()
            .map(|song| &song.path)
            .collect::<Vec<&String>>()
    );
    Ok(())
}
```

## Further use

Instead of reinventing ways to fetch a user library, play songs, etc,
and embed that into bliss, it is easier to look at the 
[Library](https://github.com/Polochon-street/bliss-rs/blob/master/src/library.rs#L12)
trait.

By implementing a few functions to get songs from a media library, and store
the resulting analysis, you get access to functions to analyze an entire
library (with multithreading), and to make playlists easily.

See [blissify](https://crates.io/crates/blissify) for a reference
implementation.

## Acknowledgements

* This library relies heavily on [aubio](https://aubio.org/)'s
  [Rust bindings](https://crates.io/crates/aubio-rs) for the spectral /
  timbral analysis, so a big thanks to both the creators and contributors
  of librosa, and to @katyo for making aubio bindings for Rust.
* The first part of the chroma extraction is basically a rewrite of
  [librosa](https://librosa.org/doc/latest/index.html)'s
  [chroma feature extraction](https://librosa.org/doc/latest/generated/librosa.feature.chroma_stft.html?highlight=chroma#librosa.feature.chroma_stftfrom)
  from python to Rust, with just as little features as needed. Thanks
  to both creators and contributors as well.
* Finally, a big thanks to
  [Christof Weiss](https://www.audiolabs-erlangen.de/fau/assistant/weiss)
  for pointing me in the right direction for the chroma feature summarization,
  which are basically also a rewrite from Python to Rust of some of the
  awesome notebooks by AudioLabs Erlangen, that you can find
  [here](https://www.audiolabs-erlangen.de/resources/MIR/FMP/C0/C0.html).