Wavelength

Wavelength is a cross-platform music app built on top of YouTube Music, delivering an ad-free listening experience with support for offline downloads and high-fidelity sound quality, all the way up to Hi-Res Lossless FLAC (24-bit/192kHz).

Word-synced lyrics with a 🍎 familiar interface.

Build your own music library with saves, playlists, and artists you like.

Feature Highlights

• Entirety of YouTube Music's catalog, completely ad-free.
• Include normal YouTube Videos in your playlists in-case a certain track/remix is unavailable on normal streaming services.
• High Quality Audio: up-to 320kbps AAC
• Hi-Res Lossless Audio: Available up-to 24-bit/192kHz FLAC
• Downloads & offline playback.
• Download supported songs in up to Hi-Res Lossless.
• Discord Mode (Rich Presence, Desktop-only)
• Apple Music-like live album covers.
• UI polish alike Apple Music in many ways.
• Word-synced/Line-synced lyrics with Apple Music-like animations.

Source

Wavelength gets songs from YouTube and Tidal. However, the primary source is Wavelength's own store. In-case a song is not available on Wavelength's catalog, your phone or desktop runs an extractor on your side called tydle that extracts the song from YouTube on your device, and starts playback immediately. In the background, Wavelength sends a request to a server that collects the Song's stream from YouTube and stores it in Wavelength's own Google Cloud Storage bucket as HLS. The collector also collects the Lossless version of the stream, which itself is stored in Wavelength's store, and is also reencoded to 256kbps AAC and 320kbps AAC for adaptive streaming on Mobile.

Wavelength always prioritizes streaming natively (from Wavelength's servers) rather than redirecting to a Tidal URL or proxying yt-dlp. For this reason, the web version might just be kind of, slow, because if a song is unavailable on Wavelength's catalog, playback on web will wait until it gets collected. However, the problem doesn't exist for Desktop/Mobile because tydle is available.

However, even though this architecture costs more than just a redirect, it allows for High Quality Audio playback always, even when Tidal/YouTube push a breaking change to their backends, because most-likely a popular track, or a track that has been played before, is already stored in Wavelength's store, so it can simply bypass YouTube/Tidal altogether and provide Hi-Res Lossless content with no hoops.

Credits

• hifi-api for creating the Tidal Hi-Fi extraction API used by the collector service.
• am-lyrics for the Apple Music style synced lyrics. Wavelength has the lyrics fetch logic rewritten in Go for a single source (Lyrics Service) of getting the lyrics on both Svelte and Flutter, as well as rewriting the UI rendering logic from Lit to Svelte. (For integration into the SvelteKit codebase.)

Getting Started

Clone the project.

$ git clone https://github.com/Dev-Siri/wavelength

NOTE: Each of these applications have their .env.example, make sure you fill these variables before running them.

Desktop

Run the SvelteKit app with dev mode.

$ bun dev

To run the desktop app in dev mode, you will need to have the Rust toolchain installed on your system. Then run the tauri command.

$ bun tauri dev

Mobile

Make sure you have Flutter installed. You'll also need the native tooling for the platform you're running on: Android requires Android-Studio and additional command-line tools and packages installed. iOS requires XCode to be installed on your Mac. Then you can start the application in dev mode:

$ flutter run

Backend

Almost all microservices are entirely written in Go, with one crucial service, the YouTube Scraper, written in TypeScript (Node) for use of the YouTube.js library to retrieve data from the platform.

To run the entirety of the project, you need to have Docker installed on your system. The project includes a docker-compose.yml in the /server directory. Use the compose commands to start all the microservices up:

$ cd server
$ docker compose up
# shut all services down
$ docker compose down

The microservices use gRPC for communication. If you are looking to make any changes to the protobuf definitions, you need to run make to regenerate the gRPC client/server code.

# generate gRPC definitions
$ make generate

Note that the command also runs a package.json script with Bun to generate TypeScript definitions. If you do not have Bun installed, then change the Makefile to use a different JavaScript package manager's command. The yt-scraper service uses Bun during development (bun run dev) but the Dockerfile builds for Node in production. (There is a bug with Bun on GCP for gRPC connections)

License

This project is MIT licensed. See LICENSE.