OBS.Ninja (OBSN) is offers here a simple and free solution to quickly enable real-time video streaming in their websites. OBSN wishes to make live video streaming development accessible to any developer, even novices, yet still remain flexible and powerful.
While OBS.Ninja does offer source-code to customize the application and UI at a low level, this isn't for beginners and it is rather hard to maintain. As well, due to the complexity of video streaming in the web, typical approaches for offering API access isn't quite feasible either.
The solution decided on isn't an SDK framework, but rather the use of embeddable IFrames and a corresponding bi-directional iframe API. An iframe allows us to embed a webpage inside a webpage, including OBS.Ninja into your own website.
Modern web browsers allow the parent website to communicate with the child webpage, giving a high-level of control to a developer, while also abstracting the complex code and hosting requirements. Functionality, we can make an OBSN video stream act much like an HTML video element tag, where you can issue commands like play, pause, or change video sources with ease.
Creating an OBSN iframe can be done in HTML or programmatically with Javascript like so:
var iframe = document.createElement("iframe");
iframe.allow="autoplay;camera;microphone";
iframe.allowtransparency="false"
iframe.src = "https://obs.ninja/?webcam";
Adding that iframe to the DOM will reveal a simple page accessing for a user to select and share their webcam. For a developer wishing to access a remote guest's stream, this makes the ingestion of that stream into production software like OBS Studios very easy. The level of customization and control opens up opportunities, such as a pay-to-join audience option for a streaming interactive broadcast experience.
An example of how this API is used by OBS.Ninja is with its Internet Speedtest, which has two OBS.Ninja IFrames on a single page. One iframe feeds video to the other iframe, and the speed at which it does this is a measure of the system's performance. Detailed stats of the connection are made available to the parent window, which displays the results. https://obs.ninja/speedtest
More community-contributed IFRAME examples can be found here: https://github.com/steveseguin/obsninja/tree/master/examples
A sandbox of options is available at this page, too: https://obs.ninja/iframe You can enter an OBS.Ninja URL in the input box to start using it. For developers, viewing the source of that page will reveal examples of how all the available functions work, along with a way to test and play with each of them. You can also see here for the source-code on GitHub: https://github.com/steveseguin/obsninja/blob/master/iframe.html
One thing to note about this iframe API is that it is a mix of URL parameters given to the iframe src URL, but also the postMessage and addEventListener methods of the browser. The later is used to dynamically control OBS.Ninja, while the former is used to initiate the instance to a desired state.
For more information on the URL parameters thare are available, please see: https://github.com/steveseguin/obsninja/wiki/Advanced-Settings
Some of the more interesting ones primarily for iframe users might include:
- &webcam
- &screenshare
- &videodevice=1 or 0
- &audiodevice=1 or 0
- &autostart
- &chroma
- &transparency
As for API, allow for dynamic messaging, below are examples of the options available:
- Mute Speaker
- Mute Mic
- Disconnect
- Change Video Bitrate
- Reload the page
- Change the volume
- Request detailed connection stats
- Access the loudness level of the audio
- Send/Recieve a chat message to other connected guests
- Get notified when there is a video connection
As for the actually details for methods and options available to dynamically control child OBSN iframe, they are primarily kept up to via the iframe.html file that is mentioned previously. see: iframe.html. Below is a snippet from that file:
var button = document.createElement("button");
button.innerHTML = "Mute Speaker";
button.onclick = function(){iframe.contentWindow.postMessage({"mute":true}, '*');};
iframeContainer.appendChild(button);
var button = document.createElement("button");
button.innerHTML = "Un-Mute Speaker";
button.onclick = function(){iframe.contentWindow.postMessage({"mute":false}, '*');};
iframeContainer.appendChild(button);
var button = document.createElement("button");
button.innerHTML = "Toggle Speaker";
button.onclick = function(){iframe.contentWindow.postMessage({"mute":"toggle"}, '*');}
iframeContainer.appendChild(button);
var button = document.createElement("button");
button.innerHTML = "Mute Mic";
button.onclick = function(){iframe.contentWindow.postMessage({"mic":false}, '*');};
iframeContainer.appendChild(button);
var button = document.createElement("button");
button.innerHTML = "Un-Mute Mic";
button.onclick = function(){iframe.contentWindow.postMessage({"mic":true}, '*');};
iframeContainer.appendChild(button);
var button = document.createElement("button");
button.innerHTML = "Toggle Mic";
button.onclick = function(){iframe.contentWindow.postMessage({"mic":"toggle"}, '*');};
iframeContainer.appendChild(button);
var button = document.createElement("button");
button.innerHTML = "Disconnect";
button.onclick = function(){iframe.contentWindow.postMessage({"close":true}, '*');};
iframeContainer.appendChild(button);
var button = document.createElement("button");
button.innerHTML = "Low Bitrate";
button.onclick = function(){iframe.contentWindow.postMessage({"bitrate":30}, '*');};
iframeContainer.appendChild(button);
var button = document.createElement("button");
button.innerHTML = "High Bitrate";
button.onclick = function(){iframe.contentWindow.postMessage({"bitrate":5000}, '*');};
iframeContainer.appendChild(button);
var button = document.createElement("button");
button.innerHTML = "Default Bitrate";
button.onclick = function(){iframe.contentWindow.postMessage({"bitrate":-1}, '*');};
iframeContainer.appendChild(button);
var button = document.createElement("button");
button.innerHTML = "Reload";
button.onclick = function(){iframe.contentWindow.postMessage({"reload":true}, '*');};
iframeContainer.appendChild(button);
var button = document.createElement("button");
button.innerHTML = "50% Volume";
button.onclick = function(){iframe.contentWindow.postMessage({"volume":0.5}, '*');};
iframeContainer.appendChild(button);
var button = document.createElement("button");
button.innerHTML = "100% Volume";
button.onclick = function(){iframe.contentWindow.postMessage({"volume":1.0}, '*');};
iframeContainer.appendChild(button);
var button = document.createElement("button");
button.innerHTML = "Request Stats";
button.onclick = function(){iframe.contentWindow.postMessage({"getStats":true}, '*');};
iframeContainer.appendChild(button);
var button = document.createElement("button");
button.innerHTML = "Request Loudness Levels";
button.onclick = function(){iframe.contentWindow.postMessage({"getLoudness":true}, '*');};
iframeContainer.appendChild(button);
var button = document.createElement("button");
button.innerHTML = "Stop Sending Loudness Levels";
button.onclick = function(){iframe.contentWindow.postMessage({"getLoudness":false}, '*');};
iframeContainer.appendChild(button);
var button = document.createElement("button");
button.innerHTML = "Say Hello";
button.onclick = function(){iframe.contentWindow.postMessage({"sendChat":"Hello!"}, '*');};
iframeContainer.appendChild(button);
var button = document.createElement("button");
button.innerHTML = "previewWebcam()";
button.onclick = function(){iframe.contentWindow.postMessage({"function":"previewWebcam"}, '*');};
iframeContainer.appendChild(button);
var button = document.createElement("button");
button.innerHTML = "CLOSE IFRAME";
button.onclick = function(){iframeContainer.parentNode.removeChild(iframeContainer);};
iframeContainer.appendChild(button);
As for listening events, where the parent listens for responses or events from the OBSN child frame:
//////////// LISTEN FOR EVENTS
var eventMethod = window.addEventListener ? "addEventListener" : "attachEvent";
var eventer = window[eventMethod];
var messageEvent = eventMethod === "attachEvent" ? "onmessage" : "message";
eventer(messageEvent, function (e) {
if (e.source != iframe.contentWindow){return} // reject messages send from other iframes
if ("stats" in e.data){
var outputWindow = document.createElement("div");
var out = "<br />total_inbound_connections:"+e.data.stats.total_inbound_connections;
out += "<br />total_outbound_connections:"+e.data.stats.total_outbound_connections;
for (var streamID in e.data.stats.inbound_stats){
out += "<br /><br /><b>streamID:</b> "+streamID+"<br />";
out += printValues(e.data.stats.inbound_stats[streamID]);
}
outputWindow.innerHTML = out;
iframeContainer.appendChild(outputWindow);
}
if ("gotChat" in e.data){
var outputWindow = document.createElement("div");
outputWindow.innerHTML = e.data.gotChat.msg;
outputWindow.style.border="1px dotted black";
iframeContainer.appendChild(outputWindow);
}
if ("action" in e.data){
var outputWindow = document.createElement("div");
outputWindow.innerHTML = "child-page-action: "+e.data.action+"<br />";
outputWindow.style.border="1px dotted black";
iframeContainer.appendChild(outputWindow);
}
if ("loudness" in e.data){
console.log(e.data);
if (document.getElementById("loudness")){
outputWindow = document.getElementById("loudness");
} else {
var outputWindow = document.createElement("div");
outputWindow.style.border="1px dotted black";
iframeContainer.appendChild(outputWindow);
outputWindow.id = "loudness";
}
outputWindow.innerHTML = "child-page-action: loudness<br />";
for (var key in e.data.loudness) {
outputWindow.innerHTML += key + " Loudness: " + e.data.loudness[key] + "\n";
}
outputWindow.style.border="1px black";
}
});
This OBS.Ninja API is developed and expanded based on user feedback and requests. It is by no means complete.
Regarding versioning, I currently host past versions of OBS.Ninja, so using those past versions can ensure some level of consistency and expectation. https://obs.ninja/v12/ for example is the version 12 hosted version. The active and main production version of OBSN of course undergoes constant updates, and while I try to maintain backwards compatibility with changes to the API, it is still early days and changes might happen.
Please feel free to follow me in the OBS.Ninja Discord channel, where I post news about updates and listen to requests. The upcoming version of OBS.Ninja is also often hosted at https://obs.ninja/beta, where you can explore new features and help crush any unexpected bugs.
-steve