In 2001, in the Annodex project we proposed temporal URIs and implemented the spec for Ogg content. There are some existing example implementations that control a video’s playback time through a URL. Also, the BBC found in experiments with Firefox that “timeupdate” is more accurate than polling the “currentTime” regularly.Ĭontrolling a video’s playback through a URL Note that for subtitles it makes a lot more sense to use the existing “timeupdate” event of the video rather than creating a frequenty setInterval interrupt, since this will continue calling the function until clearInterval() is called or the window is closed. So, in the given example, every 100ms it is tested whether a new subtitle needs to be displayed for the video current playback time. The “setInterval” function is used to call a function or evaluate an expression at the specified intervall. Video.addEventListener("timeupdate", function(), 100) Var video = document.getElementsByTagName("video") įurther, if you want to stop playback at a certain time point, you can use another functionality of the HTML5 tag: the “timeupdate” event: To jump to a time offset in a video, all you have to do in javascript is:
This is very useful to directly jump between different sections in the video, such as exemplified in the BBC’s recent R&D TV demo. Right now, you can use the video element’s “currentTime” property to read and set the current playback position of a video resource. I will explain the approaches that can be applied on the HTML5 tag for such deep video interaction.Ĭontrolling a video’s playback with javascript
Such direct access can be achieved either by providing a javascript interface through which a video’s playback position can be controlled, or by using URLs that directly communicate with the Web server about controlling the playback position. We need direct access to time offsets and sections of videos. Startbutton.For many years now I have been progressing a deeper view of video on the Web than just as a binary blob.
Third, we need to add the remote stream after creating the peer connection:Ĭopy Code startbutton = document.querySelector( ' #btn') So, when the Caller wants to send a text message I make him send a chat message in SessionDescription message and once the reciever recieves it he add it to the chatting iframe he have. What I did to get it working was modifying the signaling procedure a little bit. I was interested to get text chat working with WebRTC as I knew that it is not an available feature since you can stream video/audio only. This architecture is called JSEP, JavaScript Session Establishment Protocol. The SessionDescription sent by the caller is known as an offer, and the response from the callee is an answer.
To start a session WebRTC client needs local & remote configuration information so those configuration information are sent by SessionDiscreption which conforms to SDP. You can choose whatever messaging protocol you prefer, such as SIP. However, we need a mechanism to send control messages between peers, a process known as signalling. WebRTC uses PeerConnection to communicate streams of data. I decided to use Websocket server to be working as two-way communication channel. We can establish the connection via Websockets, or use a channel management server on Google’s appengine (Like the open source apprtc application). Second, we need to set up a peer connection: Logg( ' An error occurred: ') īrowsers implementations for GetUserMedia():
Navigator.webkitGetUserMedia( " video,audio", successCallback, errorCallback) Navigator.webkitGetUserMedia(, successCallback, errorCallback)
To do video conferencing we need to do five things:Ĭopy Code // Replace the source of the video element with the stream from the camera The work is still going on WebRTC and it is supported by Google Chrome Chanary/Firefox Aurora/Opera Labs. The mission of WebRTC is to enable rich, high quality, RTC applications to be developed in the browser via simple Javascript APIs and HTML5. WebRTC is a free, open project that enables web browsers with Real-Time Communications (RTC) capabilities via simple Javascript APIs. However, now it became much easier with WebRTC as you can do video conferencing in browser without plugins! Video Conferencing is hard and needs many things like Wideband codecs (voice and video), Echo cancellation, Automatic Gain Control, Noise reduction/suppression, Dynamic jitter buffers, Error concealment, Network Traversal, P2P protocols, and Session setup. This project is implementing a simple video conference application, where you can do an online video conference between two persons opening the same html page.