ocaml-hls

Binding to hls.js

What does ocaml-hls do ?

This library allows you to add hls video players (from the hls.js library) into your ocaml app. It is indeed bound to hls.js using gen_js_api.

HLS.js is a JavaScript library that implements an HTTP Live Streaming client. It relies on HTML5 video and MediaSource Extensions for playback. I works by transmuxing MPEG-2 Transport Stream ans AAC/MP3 streams into ISO BMFF (MP4) fragments. Transmuxing is performed asynchronously using a Web Worker when available in the browser. HLS.js also support HLS + fmp4, as announce during WWDC2016.

Source: hls.js official documentation

The binding isn't done completely, there is still some types and function that are missing some value, see the hls.mli file for more details. If there is some missing values in this plugin that would be useful for your project, feel free to complete this library and to make a pull request to the master branch.

How to install and compile your project by using this plugin ?

You can use opam by pinning the repository with:

opam pin add hls https://github.com/besport/ocaml-hls

to compile your project, use:

dune build @install

Finally, install the hls plugin with:

opam install hls

How to use it?

We will present the main functions of this plugin. See the hls API and the src.hls.mli file for more details.

The first function you need to use in this plugin Hls.new_hls (), it creates a new hls video player in the form of a video_elt object that must be used as the first argument of several functions that will apply changes in your player. The Hls.new_hls function takes a config value as an optional argument: it allows you to define several parameters in your HLS players.

Example:

let config = Hls.config ~auto_start_load:true ~max_buffered_length:150
() in
let hls = Hls.new_hls ~config () in
[...]

The current config definition isn't complete for now, some of the most complex typing defnitions aren't finish yet: those values wasn't used for the project that initiate that library, only the structure was initiated. Feel free to complete src/hls.mli if necessary.

Link a video to your player

The function Hls.attach_media must be used to add a video to your player, this function takes an argument of type Dom_html.element Js.t from the Js_of_ocaml library. You can obtain that kind of value with functions like Html.To_dom.of_element, see the Js_of_ocaml official library for more details.

Hls.on item event callback

The function allows you to add, in the item hls_item, the callback function that will be executed every time an event of type evt is raised. The callback takes 2 arguments: an Ojs.t value and a Data.t value.

Hls.Events

This module regroups all the different events that can occur during the player execution, for example Hls.Events.error is raised when an error occurs.

Hls.Data

This module contains all the function you need to extract value from a Data.t element, it can for example, indicates the current error_type of an error event.