= Streamana

== Description

Streamana is a Web page which streams your camera and microphone to YouTube Live.
It uses https://github.com/davedoesdev/webm-muxer.js[webm-muxer.js] and
https://github.com/davedoesdev/ffmpeg.js[ffmpeg.js].

== Demo

You can see it in action http://foo[here]. Use Chrome 95 or later.

. Get your ingestion URL from https://studio.youtube.com[YouTube Studio].
.. Click _CREATE_ and then select _Go Live_ from the drop-down menu.
.. Under _Select stream key_, select _Create new stream key_.
.. Give your key a name.
.. You must select _HLS_ as the streaming protocol.
.. Click _CREATE_.
.. Make sure the key you created is selected.
.. Click _COPY_ next to _Stream URL_.
. Paste the URL into the _Ingestion URL_ box in Streamana.
. Click _Live_.
** If you want to see what's happening under the hood, open developer tools (F12).
. To end the stream, click _Live_ again.

You can also change various options:

* Mute and unmute your microphone by clicking on the microphone symbol.
* Hide and show your camera by clicking on the camera symbol.
* Under the drop-down menu (top-left):
** Change the camera resolution.
** Convert your camera's video to greyscale.
** Lock the camera to portrait mode (where available, e.g. mobile phones).
** Zoom the camera to fill the page.
** Select a different version of https://github.com/davedoesdev/ffmpeg.js[ffmpeg.js] to perform
   the HLS encoding.

== Customisation

You can change the look and feel of Streamana by editing link:site/streamana.html[]
and link:site/streamana.css[].

The camera video is passed through a WebGL fragment shader in link:site/shader.js[]
so you can change this to add video effects or overlays. The shader already handles
resizing and rotating the video in `main()`. The optional greyscale conversion is in
the `tpix()` function.

The page's functionality is defined in link:site/streamana.js[] and link:site/hls.js[].

link:site/hls.js[] exports a class, `HLS`, which does the heavy lifting:

* The constructor takes the following arguments:
** The https://developer.mozilla.org/en-US/docs/Web/API/MediaStream[`MediaStream`]
   containing your video and audio tracks. Note that link:site/streamana.js[] supplies
   blank video when the camera is hidden and silent audio when the microphone is muted.
** The ingestion URL.
** The URL of `ffmpeg-worker-hls.js` in https://github.com/davedoesdev/ffmpeg.js[ffmpeg.js].
   This allows your application (or the end user if required) to supply its own version,
   in accordance with LGPL.
** The desired video frame rate.
** Whether the video is rotated.
* Call the `async start()` function to start streaming.
* Call the `end()` function to stop streaming.

`HLS` extends from https://developer.mozilla.org/en-US/docs/Web/API/EventTarget[`EventTarget`]
and dispatches the following events:

* `start` when streaming has started.
* `update`, dispatched frame rate times a second. link:site/streamana.js[] reacts to this
  event by refreshing the WebGL canvas from the camera.
* `exit` when streaming has stopped.
* `error` if an error occurs.