Each YouTube video is associated with four images, listed as follows:
http://img.youtube.com/vi/youtube-video-id/0.jpg
http://img.youtube.com/vi/youtube-video-id/1.jpg
http://img.youtube.com/vi/youtube-video-id/2.jpg
http://img.youtube.com/vi/youtube-video-id/3.jpg
The first one is a full size image and others are thumbnail images.
Eg: for the video http://www.youtube.com/watch?v=JW5meKfy3fY
Here the youtube-video-id is 'JW5meKfy3fY', to get the thumbnails we can use the following urls:
YouTube video thumbnail generation using JavaScript
function getThumbnail( yUrl, imageSize ){
if( yUrl === null ){
return "";
}
imageSize = (imageSize === null) ? 0 : imageSize;
var vId;
var results;
//getting video id using regular expression
results = yUrl.match("[\\?&]v=([^&#]*)");
vId = results[1];
if(imageSize == 0 ){
// small image
return "http://img.youtube.com/vi/"+vId+"/2.jpg";
}else {
// large image
return "http://img.youtube.com/vi/"+vId+"/0.jpg";
}
}
Note: This post is for my reference only.
