Package 'video'

Add Language Support

Description

Enabling languages (other than English) to appear as tooltips and other buttons in video.js widgets.

Usage

addVideoLanguages(video, languages)

availableLanguages()

Arguments

video	A video
languages	A character vector of languages to support in the video. See availableVideoLanguages() for a full list

Details

If any languages are missing, you can add a separate script in the head of the application that will apply the language to all videos. See https://videojs.com/guides/languages/ for more details

Value

An updated video with extra language support

Examples

video <- video("https://vjs.zencdn.net/v/oceans.mp4")
video <- addVideoLanguages(video, c("es", "fr", "de"))

if (interactive()) {
  library(shiny)

  ui <- fluidPage(lang = "fr", video)
  server <- function(input, output) {}
  shinyApp(ui, server)
}

---

Guess Video Format Type

Description

If no type is provided when generating a video.js video, then the format needs to be guessed. Included in the package is a dataset of the default type of each video. This will give the default type of each file provided.

Usage

guessVideoFormat(files)

Arguments

files

A vector of URL paths (relative or absolute) to videos

Value

A vector the same length as files of the video types.

Examples

guessVideoFormat("video.mp4")

---

Add Text Tracks to Video

Description

video.js contains the ability to include tracks with the video, including subtitles, captions and descriptions. includeTextTracks will make sure that they are included on load, and find the defaults to embed with the video.

Usage

includeTextTracks(
  video,
  files,
  language = "en",
  label = "English",
  kind = "subtitles",
  default = FALSE
)

Arguments

video	A video()
files	A vector of WebVTT files that contain "cues" of when text should appear, hide and what text to display
language	The valid BCP 47 code for the language of the text track, e.g. "en" for English or "es" for Spanish.
label	Short descriptive text for the track that will used in the user interface. For example, in a menu for selecting a captions language.
kind	An optional vector to match the type of text tracks in files: subtitles (default): Translations of the dialogue in the video for when audio is available but not understood. Subtitles are shown over the video. captions Transcription of the dialogue, sound effects, musical cues, and other audio information for viewer who are deaf/hard of hearing, or the video is muted. Captions are also shown over the video. chapters Chapter titles that are used to create navigation within the video. Typically, these are in the form of a list of chapters that the viewer can use to navigate the video. descriptions Text descriptions of the action in the content for when the video portion isn't available or because the viewer is blind or not using a screen. Descriptions are read by a screen reader or turned into a separate audio track. metadata Tracks that have data meant for JavaScript to parse and do something with. These aren't shown to the user.
default	The boolean default attribute can be used to indicate that a track's mode should start as "showing". Otherwise, the viewer would need to select their language from a captions or subtitles menu.

Details

All vectors must either be the same length as files or of length 1. In the latter, they will be applied to all files supplied.

Value

An updated video with text tracks included

Examples

vid <- video("https://vjs.zencdn.net/v/oceans.mp4")
includeTextTracks(vid, "url/to/subtitles.vtt")

---

Run {video} Example Applications

Description

Run {video} Example Applications

Usage

runVideoExample(example = "basic", display.mode = "showcase", ...)

availableVideoExamples()

Arguments

example	Name of the example to load. Current examples include: basic Basic example of video in use full Basic example of using all buttons available in video server Example showing server-side functionality
display.mode	The mode in which to display the application. By default set to "showcase" to show code behind the example.
...	Optional arguments to send to shiny::runApp

Value

This function does not return a value; interrupt R to stop the application (usually by pressing Ctrl+C or Esc).

Examples

availableVideoExamples()

if (interactive()) {
  library(shiny)
  library(video)

  runVideoExample("server")
}

---

Video Player

Description

A video player that can be embedded in HTML pages.

Usage

video(
  files,
  format = NULL,
  options = list(),
  seek_ping_rate = 1000,
  width = NULL,
  height = NULL,
  elementId = NULL
)

Arguments

files	A vector of file paths or URLs pointing
format	An optional list of formats of video
options	A named list of options to apply to the video. List of available options available in Details
seek_ping_rate	Number of milliseconds between each update of 'input${id}_seek' while playing. Default is set to 1000. If set to 0, then 'input${id}_seek' will not exist.
width, height	Must be a valid CSS unit (like '100%', '400px', 'auto') or a number, which will be coerced to a string and have 'px' appended. Use NA for it to use the original video width/height.
elementId	HTML id tag to be given to the video player element

Details

Here are some more common options to implement:

autoplay

Whether or not the video will autoplay on load. NOTE: There is not a guarantee autoplay will work in the browser.

FALSE

Default: Video won't autoplay

TRUE

Video will use browser's autoplay

"muted"

Will mute the video and then manually call play() on loadstart(). Likely to work on browsers

"play"

Will call play() on loadstart(), similar to browser autoplay

controls

Determines whether or not the player has controls that the user can interact with. By default video will include controls even if not specified in the options.

poster

A URL to an image that displays before the video begins playing. This is often a frame of the video or a custom title screen.

For a full list of available options check out https://videojs.com/guides/options/

Value

A shiny.tag containing all of the required options for a videojs JS object to be initialised in a shiny application.

On the server side there will be up to four additional objects available as inputs:

{id}_playing

A logical value as to whether or not the video is playing audio

{id}_seek

(If seek_ping_rate > 0) the current time of the track loaded

{id}_duration

The duration of the track loaded

Examples

if (interactive()) {
  library(shiny)

  ui <- fluidPage(
    title = "howler.js Player",
    video("https://vjs.zencdn.net/v/oceans.mp4")
  )

  server <- function(input, output) {
  }

  runShiny(ui, server)
}

---

Update video.js Server-Side

Description

Change the state of the video player from the server.

playVideo, pauseVideo and stopVideo will all be applied to the current video.

changeVideo will update the track to the URL or file specified.

updatePlaybackRate will change how fast the video is playing.

Usage

playVideo(id, session = getDefaultReactiveDomain())

pauseVideo(id, session = getDefaultReactiveDomain())

stopVideo(id, session = getDefaultReactiveDomain())

seekVideo(id, seek, session = getDefaultReactiveDomain())

changeVideo(id, files, format = NULL, session = getDefaultReactiveDomain())

updatePlaybackRate(id, playrate = 1, session = getDefaultReactiveDomain())

Arguments

id	ID of the video to update
session	Shiny session
seek	Time (in seconds) to set the position of the track
files	A vector of file paths or URLs pointing
format	An optional list of formats of video
playrate	Speed of playback of the video. Default is set to 1 (normal speed)

Value

Updates the the state of the specified video in the shiny application.

Examples

if (interactive()) {
  library(shiny)

  ui <- fluidPage(
    title = "howler.js Player",
    video(
      "https://vjs.zencdn.net/v/oceans.mp4",
      elementId = "video"
     ),
    actionButton("pause", "Pause Video")
  )

  server <- function(input, output) {
    observeEvent(input$pause, pauseVideo("video"))
  }

  runShiny(ui, server)
}

---

Shiny bindings for video

Description

Output and render functions for using video within Shiny applications and interactive Rmd documents.

Usage

videoOutput(outputId, width = "100%", height = "400px")

renderVideo(expr, env = parent.frame(), quoted = FALSE)

Arguments

outputId	output variable to read from
width, height	Must be a valid CSS unit (like '100%', '400px', 'auto') or a number, which will be coerced to a string and have 'px' appended.
expr	An expression that generates a video
env	The environment in which to evaluate expr.
quoted	Is expr a quoted expression (with quote())? This is useful if you want to save an expression in a variable.

Value

An output or render function that enables the use of the widget within Shiny applications.

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