JQuery thumbnail src rotator on hover (multiple images)

Situation: We've got this DIV with thumbnails who need their src being changed on hover:

<div id="moreVideos">
<span class="mb">
    <a href="#" onclick="javascript:loadAndPlayVideo('qrO4YZeyl0I');return false;" class="ml">
        <img src="http://i.ytimg.com/vi/qrO4YZeyl0I/default.jpg" id="thumb_qrO4YZeyl0I" class="mvThumb" title="Lady Gaga - Bad Romance">
    </a
</span>
<span class="mb">
    <a class="ml" onclick="javascript:loadAndPlayVideo('niqrrmev4mA');return false;" href="#">
        <img title="Lady Gaga - Alejandro" class="mvThumb" id="thumb_niqrrmev4mA" src="http://i.ytimg.com/vi/niqrrmev4mA/default.jpg">
    </a>
</span>
<span class="mb">
    <a href="#" onclick="javascript:loadAndPlayVideo('qrO4YZeyl0I');return false;" class="ml">
        <img src="http://i.ytimg.com/vi/qrO4YZeyl0I/default.jpg" id="thumb_qrO4YZeyl0I" class="mvThumb" title="Lady Gaga - Bad Romance">
    </a
</span>
<span class="mb">
    <a class="m开发者_如何学Gol" onclick="javascript:loadAndPlayVideo('niqrrmev4mA');return false;" href="#">
        <img title="Lady Gaga - Alejandro" class="mvThumb" id="thumb_niqrrmev4mA" src="http://i.ytimg.com/vi/niqrrmev4mA/default.jpg">
    </a>
</span>

Problem: On thumbnail hover we need to change the thumbnail src every 2 seconds from default.jpg -> 1.jpg -> 2.jpg -> 3.jpg -> default.jpg (loop through them while the mouse is hovering the thumb, after mouse out it need to stop and stay on the current image)

What I've tried: Plenty of sample codes from other websites and the JQuery cycle plugin. Trying to use this solution failed: jquery continuous animation on mouseover

Will be used on: http://ListAndPlay.com

I'm very curious in how you would solve a problem like this :)!

Try this (demo)... I also extracted out the inline call to loadAndPlayVideo:

$(document).ready(function(){

 $('a.ml').click(function(){
  loadAndPlayVideo( $(this).find('img').attr('id').replace(/thumb_/,'') );
  return false;
 });

 var timer,
  count = 0,
  cycle = function(el){
    var s = el.attr('src'),
     root = s.substring( 0, s.lastIndexOf('/') + 1 );
    count = (count+1)%4;
    el.attr('src', root + ((count===0) ? 'default' : count) + '.jpg');
 };

 $('.mb img').hover(function(){
   var $this = $(this);
   cycle($this);
   timer = setInterval(function(){ cycle($this); }, 1000);
 }, function(){
   clearInterval(timer);
 });

});

HTML

<!-- changed the "moreVideos" id to class, assuming you'll have more than one block -->
<div class="moreVideos"> 
<span class="mb">
    <a class="ml" href="#">
        <img src="http://i.ytimg.com/vi/qrO4YZeyl0I/default.jpg" id="thumb_qrO4YZeyl0I" class="mvThumb" title="Lady Gaga - Bad Romance">
    </a
</span>
<span class="mb">
    <a class="ml" href="#">
        <img title="Lady Gaga - Alejandro" class="mvThumb" id="thumb_niqrrmev4mA" src="http://i.ytimg.com/vi/niqrrmev4mA/default.jpg">
    </a>
</span>
<span class="mb">
    <a class="ml" href="#">
        <img src="http://i.ytimg.com/vi/qrO4YZeyl0I/default.jpg" id="thumb_qrO4YZeyl0I" class="mvThumb" title="Lady Gaga - Bad Romance">
    </a
</span>
<span class="mb">
    <a class="ml" href="#">
        <img title="Lady Gaga - Alejandro" class="mvThumb" id="thumb_niqrrmev4mA" src="http://i.ytimg.com/vi/niqrrmev4mA/default.jpg">
    </a>
</span>

Update: To have a variable number of thumbs for each image, I updated the demo too allow you to add a data-thumbs attribute containing either the file name (if all thumbs use the same root url), or full urls for each thumb.

<img src="http://i.ytimg.com/vi/qrO4YZeyl0I/default.jpg" data-thumbs="default.jpg, 1.jpg, http://i.ytimg.com/vi/qrO4YZeyl0I/2.jpg, 3.jpg" id="thumb_qrO4YZeyl0I" class="mvThumb" title="Lady Gaga - Bad Romance">

For example, the above image will only work if the url for thumb "2.jpg" has the same root (http://i.ytimg.com/vi/qrO4YZeyl0I/) as used in the "src" attribute because the code is modifying the url of the currently shown url. For images in different locations, use the full url for each thumb inside the data-thumbs attribute.

$(function() {

  $('a.ml').click(function() {
    loadAndPlayVideo($(this).find('img').attr('id').replace(/thumb_/, ''));
    return false;
  });

  var timer;

  function cycle(el) {
    var s = el.attr('src'),
      root = s.substring(0, s.lastIndexOf('/') + 1),
      files = el.attr('data-thumbs').split(/\s*,\s*/),
      count = parseInt(el.attr('data-count'), 10) || 0;
    count = (count + 1) % files.length;
    el.attr({
      'src': files[count].indexOf('http') > -1 ? files[count] : root + files[count],
      'data-count': count
    });
  }

  $('.mb img').hover(function() {
    var $this = $(this);
    cycle($this);
    timer = setInterval(function() {
      cycle($this);
    }, 1000);
  }, function() {
    clearInterval(timer);
  });

});

I hate to start a whole new question and have to copy Mottie's code in this question to ask it. The answer posted works great, and my only question is how to modify it to allow a variable number of thumbnail images.

The example shown loops from default.jpg -> 1.jpg -> 2.jpg -> 3.jpg -> default.jpg which is great if you have only four images in each directory of thumbnails. But what if there are a different number of thumbs for each of the image src links? For example, what if the first image has 6 thumbs, the second image has 8 thumbs, and the third image has 11 thumbs. What's the secret to making the code not care how many thumbs are in the directory of images so it will loop through all of them regardless of the number of thumbs?