How to correctly use oembed to pull thumbs from youtube

问题

I show a lot of thumbs on my homepage from youtube videos. I was using this function below to grab the thumb from a youtube url which works fast but it doesn't work for url's in the shortned form like youtu.be/JSHDLSKL.

function get_youtube_screen_link( $url = '', $type = 'default', $echo = true ) {
if( empty( $url ) )
    return false;

if( !isset( $type ) )
    $type = '';

$url = esc_url( $url );

preg_match("|[\\?&]v=([^&#]*)|",$url,$vid_id);

if( !isset( $vid_id[1] ) )
    return false;

$img_server_num =  'i'. rand(1,4);

switch( $type ) {
    case 'large':
        $img_link = "http://{$img_server_num}.ytimg.com/vi/{$vid_id[1]}/0.jpg";
        break;
    case 'first':
        // Thumbnail of the first frame
        $img_link = "http://{$img_server_num}.ytimg.com/vi/{$vid_id[1]}/1.jpg";
        break;
    case 'small':
        // Thumbnail of a later frame(i'm not sure how they determine this)
        $img_link = "http://{$img_server_num}.ytimg.com/vi/{$vid_id[1]}/2.jpg";
        break;
    case 'default':
    case '':
    default:
        $img_link = "http://{$img_server_num}.ytimg.com/vi/{$vid_id[1]}/default.jpg";
        break;
}
if( $echo )
    echo $img_link;
else
    return $img_link;

}

So I tried to use Oembed to get the thumbs instead which works for all variations of the youtube url but it retrieves the 480px/360px thumb which causes a lot of cropping to get it down to the 120px/90px size I use to display them. The other issue was it caused my page speed to increase by 4 seconds which Im guessing is a problem with the way I'm implementing it. Here's how I call the thumb inside a loop.

<?php 
 require_once(ABSPATH.'wp-includes/class-oembed.php');
 $oembed= new WP_oEmbed;
 $name = get_post_meta($post->ID,'video_code',true);
 $url = $name;
//As noted in the comments below, you can auto-detect the video provider with the following
 $provider = $oembed->discover($name);
//$provider = 'http://www.youtube.com/oembed';
 $video = $oembed->fetch($provider, $url, array('width' => 300, 'height' => 175));
 $thumb = $video->thumbnail_url; if ($thumb) { ?>
   <img src="<?php echo $thumb; ?>" width="120px" height="90px" />
<?php } ?>

So how should I be doing this to maximize efficiency?

回答1:

I came across this page from youtube explaining their oembed support, They mentioned that they output to json format so I made a function that gets the json data and then enables you to use it.

Feel free to ask if you need more help.

<?php

$youtube_url = 'http://youtu.be/oHg5SJYRHA0'; // url to youtube video

function getJson($youtube_url){

    $baseurl = 'http://www.youtube.com/oembed?url='; // youtube oembed base url
    $url = $baseurl . $youtube_url . '&format=json'; // combines the url with format json

    $json = json_decode(file_get_contents($url)); // gets url and decodes the json

    return $json;

}

$json = getJson($youtube_url);

// from this point on you have all your data placed in variables.

$provider_url = $json->{'provider_url'};
$thumbnail_url = $json->{'thumbnail_url'};
$title = $json->{'title'};
$html = $json->{'html'};
$author_name = $json->{'author_name'};
$height = $json->{'height'};
$thumbnail_width = $json->{'thumbnail_width'};
$thumbnail_height = $json->{'thumbnail_height'};
$width = $json->{'width'};
$version = $json->{'version'};
$author_url = $json->{'author_url'};
$provider_name = $json->{'provider_name'};
$type = $json->{'type'};

echo '<img src="'.$thumbnail_url.'" />'; // echo'ing out the thumbnail image

回答2:

Ok I came up with a solution from pieces of other questions. First we need to get the id from any type of url youtube has using this function.

function getVideoId($url)
{
$parsedUrl = parse_url($url);
if ($parsedUrl === false)
    return false;

if (!empty($parsedUrl['query']))
{
    $query = array();
    parse_str($parsedUrl['query'], $query);
    if (!empty($query['v']))
        return $query['v'];
}

if (strtolower($parsedUrl['host']) == 'youtu.be')
    return trim($parsedUrl['path'], '/');

return false;
}

Now we can get use YouTube Data API to get the thumbnail from the video id. Looks like this.

<?php
  $vid_id = getVideoId($video_code);
  $json = json_decode(file_get_contents("http://gdata.youtube.com/feeds/api/videos/$vid_id?v=2&alt=jsonc"));
  echo '<img src="' . $json->data->thumbnail->sqDefault . '" width="176" height="126">'; 
?>

The problem is that is causing an extra 2 seconds load time so I simply use the $vid_id and place it inside http://i3.ytimg.com/vi/<?php echo $vid_id; ?>/default.jpg which gets rid of the 2 seconds added by accessing the youtube api.

来源：https://stackoverflow.com/questions/10377244/how-to-correctly-use-oembed-to-pull-thumbs-from-youtube

标签

youtube-api

thumbnails

oembed