问题
I'm not able to get the correct video duration/length (in seconds) of a loaded/cued video via the getDuration() method of the YouTube Player API; the same method, however, returns a valid value once the video starts playing! Wondering how YouTube is able to show the valid duration of a loaded/cued video.
When I load this HTML page with a 15 second video clip, I get the following debug output:
state = 5 duration = -0.000025
When I hit the Play button, I get the following debug output:
state = 3 duration = 15,
Would greatly appreciate a solution or a workaround. Loading, and immediately playing and pausing the player would be not my favorite method.
<html>
<head>
<script type="text/javascript">
var videoId;
videoId = 'http://www.youtube.com/v/4TSJhIZmL0A'; // bbc
// videoId = 'http://www.youtube.com/v/ezwyHNs_W_A'; // physics
function $(id) {
return document.getElementById(id);
}
</script>
<script src="http://www.google.com/jsapi"></script>
<script>
google.load("swfobject", "2.1");
</script>
</head>
<body>
<table>
<tr><td>
<div id="player">
You need Flash player 8+ and JavaScript enabled to view this video.
</div>
<script>
var ytplayer;
function myOnPlayerStateChange(state) {
switch(state) {
case 1: // playing
$("out").innerHTML += " playing";
break;
case 2: // paused
$("out").innerHTML += " paused";
break;
case 0: // ended
$("out").innerHTML += " ended";
break;
case -1: // unstarted
case 3: // buffering
case 5: // cued
$("out").innerHTML += " state = " + state;
break;
default: // unknown
$("out").innerHTML += " state = " + state;
break;
}
$("out").innerHTML += " duration = " + ytplayer.getDuration() + ",";
}
function myOnPlayerError(errorCode) {
$("out").innerHTML += " Error occurred: " + errorCode;
}
function onYouTubePlayerReady(playerId) {
ytplayer = ytplayer || $(playerId);
ytplayer.addEventListener("onStateChange", "myOnPlayerStateChange");
ytplayer.addEventListener("onError", "myOnPlayerError");
}
var params = { allowScriptAccess: "always", bgcolor: "#cccccc" };
var atts = { };
swfobject.embedSWF(videoId + "?border=0&enablejsapi=1&playerapiid=" + 'player', 'player', 425, 344, "8", null, null, params, atts);
</script>
</td></tr>
</table>
<div id="out"></div>
<div id="err"></div>
</body>
</html>
回答1:
Solution 1
You can use YouTube Data API to access most of the information about the video, including duration:
<script type="text/javascript">
function youtubeFeedCallback(json){
document.write(json["data"]["duration"] + " second(s)");
}
</script>
<script type="text/javascript" src="http://gdata.youtube.com/feeds/api/videos/4TSJhIZmL0A?v=2&alt=jsonc&callback=youtubeFeedCallback&prettyprint=true"></script>
Demo here
When using jQuery you can use $.getJSON() to make things easier.
Solution 2
Seems like YouTube JavaScript API v3 allows you to get the correct duration inside the onYouTubePlayerReady() event. All you need to do is pass &version=3 when calling swfobject.embedSWF() method.
Demo here
回答2:
Following these steps:
1. Get youtube video id
2. Use youtube API to get duration (ISO 8601 duration)
3. Convert ISO 8601 duration to time
Using Jquery:
// convert ISO 8601 duration
function covtime(youtube_time){
array = youtube_time.match(/(\d+)(?=[MHS])/ig)||[];
var formatted = array.map(function(item){
if(item.length<2) return '0'+item;
return item;
}).join(':');
return formatted;
}
// print video duration
$('iframe').each(function(i) {
var ifr = $(this);
var regExp = /^.*(youtu\.be\/|v\/|u\/\w\/|embed\/|watch\?v=|\&v=)([^#\&\?]*).*/;
var match = ifr.attr('src').match(regExp); // get youtube video id
if (match && match[2].length == 11) {
var youtubeUrl = "https://www.googleapis.com/youtube/v3/videos?id=" + match[2]
+ "&key=AIzaSyDYwPzLevXauI-kTSVXTLroLyHEONuF9Rw&part=snippet,contentDetails";
$.ajax({
async: false,
type: 'GET',
url: youtubeUrl,
success: function(data) {
var youtube_time = data.items[0].contentDetails.duration;
var duration = covtime(youtube_time);
if(ifr.next().is('.time')) {
ifr.next().html(duration);
}
}
});
}
});
回答3:
"Loading, and immediately playing and pausing the player would be not my favorite method."
I don't think there is any other method.
In my case it works well, even for a satellite internet user.
Here is my code :
// I set youtube player-ready event to a variable for irrelevant reasons
function onYouTubePlayerReady(playerid) {
youtube_player_ready;
}
youtube_player_ready = function(playerid) {
// load video
document.getElementById(playerid).cueVideoById(yt_video_id);
// mute video
document.getElementById(playerid).mute();
// play video to get meta data
document.getElementById(playerid).playVideo();
yt_get_duration[index] = function(){
// if duration is available
if (document.getElementById(playerid).getDuration() > 0) {
// pause video
document.getElementById(playerid).pauseVideo();
// unmute
document.getElementById(playerid).unMute();
// save duration
video_duration = document.getElementById(playerid).getDuration();
}
// else keep trying
else {
setTimeout(yt_get_duration[index], 150)
}
}
// get duration
yt_get_duration[index]();
}
回答4:
Here one that converts the time over for you.
<script type="text/javascript">
function youtubeFeedCallback(json){
var totalSec = json["data"]["duration"];
var hours = parseInt( totalSec / 3600 ) % 24;
var minutes = parseInt( totalSec / 60 ) % 60;
var seconds = totalSec % 60;
var result = (hours < 1 ? "" : hours + ":") + (minutes < 1 ? "0" : minutes) + ":" + (seconds < 10 ? "0" + seconds : seconds);
document.write(result);
}
</script>
<script type="text/javascript" src="http://gdata.youtube.com/feeds/api/videos/LzPWWpKlvqQ?v=2&alt=jsonc&callback=youtubeFeedCallback&prettyprint=true"></script>
回答5:
Using jQuery
var youTubeURL = 'http://gdata.youtube.com/feeds/api/videos/oHg5SJYRHA0?v=2&alt=json';
var json = (function () {
$.ajax({
'async': false,
'global': false,
'url': youTubeURL,
'dataType': "jsonp", // necessary for IE9
crossDomain: true,
'success': function (data) {
var duration = data.entry.media$group.yt$duration.seconds;
}
});
})();
来源：https://stackoverflow.com/questions/2086260/youtube-player-api-how-to-get-duration-of-a-loaded-cued-video-without-playing-i