Building HTML5 media (video, audio) controls with JavaScript

by , Oct. 19, 2010 at 08:59 PM

Scripts: html5

With te earlier versions of HTML, it was impossible to embed and play media on a webpage along without invoking third part plugins that didn't belong to HTML itself.
Here I am talking about Flash, Silverlight, Quick times, and so on...
The great HTML5 has come with handful and nice features to enrich and innovate the web applications.
One of these is the inclusion of MediaElement. (using Audio and/or video files on a webpage as we used to with images).
You do not need Flash any more to play you media on your page unless the visitors of your page still use the old browsers or so called, the non-Advanced browser.
Then you must foresee a way to a fallback for those browsers.
Not all browsers support yet HTML5 even IE8 (InternetExplorer8) doesn't support HTML5. However, Microsoft is promising to full integrate HTML5 in IE9, wich is to come.
Those browsers which support HTML5 have their custom media controls, which look differently to each other.
Here is the sketch of different controls of browsers:Native controls

If you want to build up you own customized Media controls, it is possible because HTML5 dispose Media properties, Media events you can manipulate in the DOM to control the media object and build your own media controls.


Media properties are:
"error", "src", "currentSrc", "networkState", "preload", "buffered", "readyState", "seeking", "currentTime", "startTime", "duration", "paused", "defaultPlaybackRate", "playbackRate", "played", "seekable", "ended", "autoplay", "loop", "controls", "volume", "muted"

Media events are:
"loadstart", "progress", "suspend", "emptied","stalled", "play","pause", "loadedmetadata", "loadeddata","waiting", "playing", "canplay", "canplaythrough", "seeking","seeked", "timeupdate", "ended", "ratechange", "durationchange", "volumechange"

All these properties and events are found in the spec. of W3 from May 2010.

Now the question is how to handle all this to build a controls. Most of these properties and events are more explanatory of its own. I cannot go explaining all these events and props on here otherwise it will be worth to write up a whole book on this.
But I will try to explain some.
Note that some of the props are read-only and cannot be change in value, others can be modified.
First of all a simple example of embed a video on a webpage:

Note to wacht this movie you have to use as web-browser (Mozilla Firefox, Safari, Chrome, or IE9) because the IE7 even IE8 cannot play the MediaElement Video or Audio and many other features of HTML5.

 

With this piece of code in this HTML page you wacht this video with a native custom controls accordingly  to the browser.

  1. //Check if the event loadstart is fired
  2. var myvideo = document.getElementsByTag('video')[0];
  3. myvideo.addEventListener('loadstart', function loadStart(){
  4. alert('Start loading...');
  5. }, false);
  6.  
  7. //Check if the event loadedmetadata is fired
  8. //var myvideo = document.getElementsByTag('video')[0];
  9. myvideo.addEventListener('loadedmetadata', function loadedData(){
  10. var videoOrigWidth = myvideo.videoWidth;
  11. var videoOrigHeight = myvideo.videoHeight;
  12. alert(videoOrigWidth + ' x ' + videoOrigHeight);
  13. }, false);
  14.  
  15. //
  16. //var myvideo = document.getElementsByTag('video')[0];
  17. var loaded_div = document.getElementById('loaded');
  18. myvideo.addEventListener('progress', Progress, false);
  19. function Progress(event) {
  20. if (event.total > 0) {
  21. loaded_div.innerHTML = (Math.floor(event.loaded / event.total * 100) + "% - " + myvideo.currentSrc);
  22. setLoadProgress((event.loaded / event.total));
  23. }
  24. }

 

In the code snippet here above you see some javascript code that may control the video element in HTML. Firstly, a defining a variable to hold the video element of the DOM when this is loaded and is ready. This video element is defined as follows var myvideo = document.getElementsByTag('video')[0];

myvideo is got from DOM which keep all the video elements in this case in an array. Because we are dealing with one video element that is why we take that first element of the array.

The loadstart and loadedmetadata are events that are fired when the media is successively the media data and metadata is start loading. Metadadata are related to the information of the media, its size, its author, ...

 

  1. // define the holders of currentTime and duration of the video
  2. var myvideo = document.getElementsByTag('video')[0];
  3. var videoDuration = document.getElementById('duration');
  4. var currentTime = document.getElementById('currentTime');
  5.  
  6. // Track the timeupdate Event, this event is important because
  7. // herein you receive periodically
  8. // the current time the video or audio has played
  9. myvideo.addEventListener('timeupdate', function(e) {
  10. //split currentTime (seconds) into separate hour/minute/second strings
  11. var seconds = e.target.currentTime;
  12. var h = Math.floor(seconds / 3600);
  13. seconds = seconds % 3600;
  14. var min = Math.floor(seconds / 60);
  15. seconds = Math.floor(seconds % 60);
  16. /* pad the minute and second strings to two digits */
  17. if (seconds.toString().length < 2)
  18. seconds = "0" + seconds;
  19. if (min.toString().length < 2)
  20. min = "0" + min;
  21. videoDuration.innerHTML = e.target.duration;
  22. currentTimeDisplay.innerHTML = h + ":" + min + ":" + seconds;
  23. }, false);

 

Here the the event timeupdate is useful, because when the media start to play it will be fired automatically and periocally within several milliseconds. It return an TimeRanges Object with the propriety for currentTime wich tells how much data has been played until now, one property for the total data of the video.

To let you see how to put into practice this simple explanation of javascript how to interact with a video. Of course to markup with html and CSS is more important to give your controls a nice feel and touch.

Click on Play to play the video, Pause to pause it and << Rewind to rewind it.

 

  1. var myvideo = document.getElementsByTag("video")[0];
  2. myvideo.addEventListenenr('timeupdate', function(e){
  3. var currentT_Holder = document.getElementById('currentT');
  4. currentT_Holder.innerHTML = e.target.currentTime;
  5. }, false);
  6. <video preload width="400">
  7. <source src="HTML5/MP4/video.mp4" type='video/mp4; codecs="avc1.42E01E, mp4a.40.2"' />
  8. <source src="HTML5/MP4/video.ogv" type='video/ogg; codecs="theora, vorbis"' />
  9. <source src="HTML5/MP4/video.webm" type='video/webm; codecs="vp8, vorbis"'/>
  10. Your browser does not support the <code>video</code> element.
  11. </video>
  12. <p>
  13. <input type="button" value="Play" onclick="myvideo.play();" />
  14. <input type="button" value="Pause" onclick="myvideo.pause();" />
  15. <input type="button" value="<< Rewind" onclick="myvideo.currentTime = 0;">
  16. <span id="currentT"></span>
  17. </p>

 

For a complete build up controls with javascript and some CSS styling visit this link :
Customized HTML5 controls with javascript

Available Comments :

Amo

Oct. 20, 2010 at 11:36 PM

HTML5 is great stuff

Cheap online prescription glasses

Jun. 27, 2012 at 03:47 PM

I was suggested this blog by my cousin. I am not sure whether this post is
written by him as nobody else know such detailed about my difficulty.
You are wonderful! Thanks!

Your Attention! Please do not post message with spam on this blog. We try to be cool to each other and post relevant comments and relating to the appropriated topic or entry. Let's try to get a nice conversation over here.

Leave a comment

Required!
Required!

Required!
Required!

Latest News

  • Dec. 23, 2014 at 05:57
    Watch the latest news summary from BBC World News. International news updated 24 hours a day.
    Read more»
  • Dec. 23, 2014 at 05:21
    The fatal shooting of an unarmed black man by a white police officer in Milwaukee is to be reviewed after a prosecutor decides not to press ...
    Read more»
  • Dec. 23, 2014 at 05:13
    A record 17,500 people turn out for the latest "anti-Islamisation" rally in the German city of Dresden, according to police estimates.
    Read more»
  • Dec. 23, 2014 at 05:10
    Some internet services have been restored in North Korea after a severe outage, amid a cyber security row with the US.
    Read more»
  • Dec. 23, 2014 at 05:02
    Counting of votes begins in Indian-administered Kashmir, where PM Narendra Modi's BJP party is trying to win power for the first time.
    Read more»
  • Dec. 23, 2014 at 03:55
    Sydney remembers the victims of the Lindt cafe siege, with the funeral of manager Tori Johnson and a memorial service for barrister Katrina ...
    Read more»
  • Dec. 23, 2014 at 03:46
    Belgian PM Charles Michel is attacked with mayonnaise and french-fries by female austerity protestors from a group calling itself Liliths.
    Read more»
  • Dec. 23, 2014 at 03:28
    Lyse Doucet on the prospect of change in Pakistan one week after the school massacre
    Read more»
  • Dec. 23, 2014 at 03:07
    Asian markets headed lower on Tuesday despite big gains on Wall Street, which closed at record highs overnight.
    Read more»
  • Dec. 23, 2014 at 02:27
    The day the Pintupi Nine entered the modern world
    Read more»
  • Dec. 23, 2014 at 02:03
    Forming bonds with one of our most feared predators
    Read more»
  • Dec. 23, 2014 at 02:03
    China's national carrier, Air China, is set to buy 60 Boeing 737 aircraft in a deal worth more than $6bn (£3.8bn).
    Read more»
  • Dec. 23, 2014 at 02:01
    So just what were the biggest 'fails' of 2014?
    Read more»
  • Dec. 23, 2014 at 02:00
    The people who prefer to be alone on 25 December
    Read more»
  • Dec. 23, 2014 at 01:50
    The agents fighting to stem jihadists on the net
    Read more»
  • Dec. 23, 2014 at 01:46
    NHS leaders warn loneliness could cause a major spike in emergency admissions
    Read more»
  • Dec. 23, 2014 at 01:44
    Meal planning for a daughter who never feels full
    Read more»
  • Dec. 23, 2014 at 01:44
    A historic year of self-doubt, nerves and instability
    Read more»
  • Dec. 23, 2014 at 01:12
    The US troops who go back as part of PTSD treatment
    Read more»
  • Dec. 23, 2014 at 01:10
    The money allocated to local authorities in England to tackle potholes and improve local roads is announced by the Department for Transport....
    Read more»

Recent Comments:

Pharmb740

Sep. 25, 2014 at 11:59 AM

Very nice site!

Pharmf503

Sep. 25, 2014 at 06:32 AM

Very nice site! cheap goods http://apeyixo2.com/ysyaqqs/4.html

Pharmf80

Sep. 23, 2014 at 06:22 PM

Very nice site!

Pharmf581

Sep. 23, 2014 at 06:22 PM

Very nice site! cheap goods http://aieopxy2.com/osovrrv/4.html

Pharmg443

Sep. 23, 2014 at 06:21 PM

Very nice site! cheap goods

Archives:

Meet me on facebook: