The hardware and bandwidth for this mirror is donated by dogado GmbH, the Webhosting and Full Service-Cloud Provider. Check out our Wordpress Tutorial.
If you wish to report a bug, or if you are interested in having us mirror your free-software or open-source project, please feel free to contact us at mirror[@]dogado.de.

Lifecycle: experimental Codecov test coverage R-CMD-check

{howler} - Interactive Audio Player

{howler} is a package that utilises the howler.js library to play audio on the modern web.

Installation

This package is not yet available on CRAN. To install the latest version:

install.packages("devtools")
devtools::install_github("ashbaldry/howler")

Usage

The HTML way to include an audio file in any shiny application/web page is to use the <audio> tag. This can generally only handle one audio file, and cannot (easily) be manipulated from the server side.

tags$audio(src = "audio/sound.mp3", type = "audio/mp3", autoplay = NA, controls = NA)

howler.js uses the Web Audio API, and with this we are able to create an audio player that can solve both of the above issues and more:

library(shiny)
library(howler)

ui <- fluidPage(
  title = "howler Example",
  howler(
    elementId = "sound", 
    tracks = list("Track 1" = "audio/track_1.mp3", "Track 2" = "audio/track_2.mp3"),
    auto_continue = TRUE,
    auto_loop = TRUE,
    seek_ping_rate = 1000
  ),
  howlerPreviousButton("sound"),
  howlerPlayPauseButton("sound"),
  howlerNextButton("sound")
)

server <- function(input, output, session) {
  observe({
    req(input$sound_seek)
    if (round(input$sound_seek) == 10) {
      pauseHowl("sound")
    } else if (round(input$sound_seek) == 20) {
      changeTrack("sound", "Track 2")
    }
  })
}

shinyApp(ui, server)

Module

The {howler} package also includes a lightweight module howlerModuleUI and howlerModuleServer that adds a bit of styling to replicate the style of a standard <audio> HTML player.

Howler module UI

Examples

All examples are available in the Examples directory and can be run locally by installing the {howler} package:

These binaries (installable software) and packages are in development.
They may not be fully stable and should be used with caution. We make no claims about them.
Health stats visible at Monitor.