rust project 2020

soundboard

cross-platform desktop application to spice up your audio/video conferences

rust project 2020

Initial requirements

  • play local file sounds on a button press over the microphone and one output
  • supported formats: mp3, wav
  • cross-platform
  • global hotkey support
  • readable config format (toml, json etc)
  • native gui
rust project 2020

Demo!

rust project 2020

Current status

  • all initial requirements implemented
  • supported formats: mp3, wav, ogg, flac, xm
  • config file format: toml
  • extra features:
    • http links as source (download)
    • multiple soundboards
    • http-api/webui with drag/drop and mobile support
    • telegram bot
  • automatic continuous builds via Github Action
  • python scrapers for myinstants.com, soundboard.com, 101soundboards.com
  • first alpha release v0.0.2 on crates.io and packaged as binary release
rust project 2020

Config file example

soundboards\favorites.toml

name = 'favorites'
position = 0

[[sound]]
hotkey = 'CTRL-P'
name = 'Nicht so tief, Rüdiger!'
path = 'nicht-so-tief-rudiger.mp3'

[[sound]]
name = 'Wer wird Millionär - Showstart'
path = 'https://www.myinstants.com//media/sounds/wer-wird-millionar-soundtracks-soundstart.mp3'
rust project 2020

Architecture overview

  • sound <--> (mpsc channel)
    • http-api <--> webapp (js/html)
    • native-gui
    • telegram bot
  • config <--> (rwlock)
    • http-api <--> webapp (js/html)
    • native-gui
    • telegram bot
  • hotkey <--> (mpsc channel)
    • http-api <--> webapp (js/html)
    • native-gui
rust project 2020

Problems

  • cross-plattform audio support
  • cross-plattform hotkey support
  • native gui: slow iteration and missing features
  • Multithreading: config files and crates
rust project 2020
problems

cross-platform audio support

  • no support for virtual microphones on any platform without additional drivers (windows, macos) or plugins (linux with pulseaudio)
    -> initial external user setup needed
  • First version with rust audio crates cpal and rodio but only supports alsa on linux. Also few updates.
    -> Switched to miniaudio: C-Library with rust-binding but maintained.
  • But miniaudio loopback stream didn't work on one arch linux dev system so we implemented native pulseaudio routing as a fallback on linux.
rust project 2020
problems

cross-platform hotkey support

  • crate hotkey-rs supported windows and linux hotkeys
  • added macos hotkey support via own c bindings
  • also needed to rewrite hotkey-rsto support multi-thread usage and deregister functionality
rust project 2020
problems

native gui: slow iteration and missing features

  • chose crate iced as our gui framework
    -> great cross-platform support, many features for such a young project
  • not optimized for performance right now and no dynamic list support
    -> big soundboards with many buttons hard to implement
  • But main problem with a native gui in rust:
    -> slow development iteration: compile times are a problem
  • current deps expand to 386 crates with default features
  • incremental builds still take 10-30 seconds
anyhow = "1.0"
bytes = "0.5"
clap = "3.0.0-beta.1"
crossbeam-channel = "0.4"
dirs = "3"
env_logger = "0.7"
hotkey-soundboard = {path = "extern/hotkey-rs", version = "0.0.1"}
log = "0.4"
miniaudio = "0.7"
once_cell = "1.4"
parking_lot = "0.11"
regex = "1"
reqwest = {version = "0.10", features = ["blocking"]}
serde = {version = "1.0", features = ["derive"]}
strum = "0.18"
strum_macros = "0.18"
tokio = {version = "0.2", features = ["macros", "full", "sync", "time"]}
toml = "0.5"
winit = "0.22"

iced = {version = "0.1", optional = true, features = ["tokio"]}
iced_native = {version = "0.2", optional = true}

futures = {version = "0.3", optional = true}
warp = {version = "0.2", optional = true}

claxon = {version = "0.4", optional = true}
hound = {version = "3", optional = true}
lewton = {version = "0.10", optional = true}
minimp3 = {version = "0.3", optional = true}
mp3-duration = {version = "0.1.10", optional = true}
ogg_metadata = {version = "0.4", optional = true}
rust project 2020
problems

Multithreading

  • five threads: http/webui, native gui, sound, hotkey and telegram bot
  • central config file management with RwLock<Arc<Config>>. Fast reads but slow writes
    -> sqlite maybe better suited
  • cross-thread communication via channels
  • we use parking_lot mutexes because std library doesn't guarantee eventual fair locking
  • no async usage but http and telegram crates use async
    -> multiple tokio runtimes
rust project 2020

Lessons learned

  • Switched to webui: fast dev iteration, also possible to use your smartphone as controller
  • Check your crates/dependencies thoroughly: last updates and issues, code quality etc.
  • Crates like crossbeam or parking_lot are useful drop-in replacements for the standard library
  • Github CI is really helpful and free for open-source projects. Cross-platform without continuous builds would be a nightmare.
  • Multithreading/async is still hard also in Rust.
rust project 2020

Questions?

Try it out or contribute via https://github.com/gamebooster/soundboard

cargo install soundboard is already possible!