下方为YouTube视频解析API源码，存储为.php文件调用即可

<?php
/**
*
* YouTuBe API
*
* @author DanMo <https://www.cheshirex.com/>
* @date 2018-08-18 19:42:30
* @version 0.26
*
*
*/
error_reporting(0);
header('Content-type: text/json;charset=utf-8');

$ui = array();
foreach($_GET as $key => $value){
$ui[$key] = trim($value);
}

if( empty($ui['vid']) ){
die('Please attach relevant parameters!');
}

define('VID',$ui['vid'] );
define('VIDEO_URL',"https://www.youtube.com/watch?v=");
define('YouTuBe_Api',"https://y2mate.com/zh-cn/analyze/ajax");
define('TEST_API_KEY', 'AIzaSyCOz5Yml_mICULfhM0s_u87l4MRvcL7_p0' );
define('API_KEY', 'AIzaSyBiMxVlkwUqqHbxVU3HJV3KcPFQPikfZwE' );

function https_curl($url,$params=false,$ispost=0){
$httpInfo = array();
$ch = curl_init();

curl_setopt( $ch, CURLOPT_HTTP_VERSION , CURL_HTTP_VERSION_1_1 );
curl_setopt( $ch, CURLOPT_USERAGENT , 'JuheData' );
curl_setopt( $ch, CURLOPT_CONNECTTIMEOUT , 60 );
curl_setopt( $ch, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt( $ch, CURLOPT_SSL_VERIFYHOST, FALSE);
curl_setopt( $ch, CURLOPT_TIMEOUT , 60);
curl_setopt( $ch, CURLOPT_RETURNTRANSFER , true );
curl_setopt ($ch, CURLOPT_FOLLOWLOCATION, true);
if( $ispost )
{
curl_setopt( $ch , CURLOPT_POST , true );
curl_setopt( $ch , CURLOPT_POSTFIELDS , $params );
curl_setopt( $ch , CURLOPT_URL , $url );
}
else
{
if($params){
curl_setopt( $ch , CURLOPT_URL , $url.'?'.$params );
}else{
curl_setopt( $ch , CURLOPT_URL , $url);
}
}
$response = curl_exec( $ch );
if ($response === FALSE) {
//echo "cURL Error: " . curl_error($ch);
return false;
}
$httpCode = curl_getinfo( $ch , CURLINFO_HTTP_CODE );
$httpInfo = array_merge( $httpInfo , curl_getinfo( $ch ) );
curl_close( $ch );
return $response;
}

function api_curl($url,$data){
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_POST, 1);
curl_setopt($curl, CURLOPT_SSL_VERIFYPEER, FALSE);
curl_setopt($curl, CURLOPT_SSL_VERIFYHOST, FALSE);
curl_setopt($curl, CURLOPT_POSTFIELDS,$data);
curl_setopt($curl, CURLOPT_HEADER,0);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
$response = curl_exec($curl);
if (curl_errno($curl)) {
return 'ERROR '.curl_error($curl);
}
curl_close($curl);
return $response ;
}

$APIs = [
'categories.list' => 'https://www.googleapis.com/youtube/v3/videoCategories',
'videos.list' => 'https://www.googleapis.com/youtube/v3/videos',
'search.list' => 'https://www.googleapis.com/youtube/v3/search',
'channels.list' => 'https://www.googleapis.com/youtube/v3/channels',
'playlists.list' => 'https://www.googleapis.com/youtube/v3/playlists',
'playlistItems.list' => 'https://www.googleapis.com/youtube/v3/playlistItems',
'activities' => 'https://www.googleapis.com/youtube/v3/activities',
];

function getApi($name){
global $APIs;
return $APIs[$name]."?";
}

function _parse_url_path($url){
$array = parse_url($url);
return $array['path'];
}

function _parse_url_query($url){
$array = parse_url($url);
$query = $array['query'];
$queryParts = explode('&', $query);
$params = [];
foreach ($queryParts as $param) {
$item = explode('=', $param);
$params[$item[0]] = empty($item[1]) ? '' : $item[1];
}
return $params;
}

function getVideoInfo($vId, $part = ['id', 'snippet', 'contentDetails', 'player', 'statistics', 'status']){
$API_URL = getApi('videos.list');
$params = [
'id' => is_array($vId) ? implode(',', $vId) : $vId,
'key' => API_KEY,
'part' => implode(', ', $part),
];
return https_curl($API_URL,$params,0);
}

function getPageContent($id){
$page = 'http://www.youtube.com/watch?v='.$id;
$arr = array(
"ssl" => array(
"verify_peer" => false,
"verify_peer_name" => false,
),
); 
$content = file_get_contents($page, false, stream_context_create($arr));
return $content;
}

function getDownloadLinks($id){
$videoMap = array(
"13" => array("3GP", "Low Quality - 176x144"),
"17" => array("3GP", "Medium Quality - 176x144"),
"36" => array("3GP", "High Quality - 320x240"),
"5" => array("FLV", "Low Quality - 400x226"),
"6" => array("FLV", "Medium Quality - 640x360"),
"34" => array("FLV", "Medium Quality - 640x360"),
"35" => array("FLV", "High Quality - 854x480"),
"43" => array("WEBM", "Low Quality - 640x360"),
"44" => array("WEBM", "Medium Quality - 854x480"),
"45" => array("WEBM", "High Quality - 1280x720"),
"18" => array("MP4", "Medium Quality - 480x360"),
"22" => array("MP4", "High Quality - 1280x720"),
"37" => array("MP4", "High Quality - 1920x1080"),
"38" => array("MP4", "High Quality - 4096x230")
);

$content = getPageContent($id);
$videos = array('MP4' => array(), 'FLV' => array(), '3GP' => array(), 'WEBM' => array());

if(preg_match("'\"url_encoded_fmt_stream_map\":\"(.*?)\"'si", $content, $r)){
$data = $r[1];
$data = explode(',', $data);

foreach($data As $cdata){
$cdata = str_replace('\u0026', '&', $cdata);
$cdata = explode('&', $cdata);

foreach($cdata As $xdata){
if(preg_match('/^sig/', $xdata)){
$sig = substr($xdata, 4);
}

if(preg_match('/^url/', $xdata)){
$url = substr($xdata, 4);
}

if(preg_match('/^itag/', $xdata)){
$type = substr($xdata, 5);
}
}
$url = urldecode($url);
$videos[$videoMap[$type][0]][$videoMap[$type][1]] = $url;
}
}
return $videos;
}
function format_bytes($size){
$units = array(' B', ' KB', ' MB', ' GB', ' TB');
for($i = 0; $size >= 1024 && $i < 4; $i++){
$size /= 1024;
}
return round($size, 2).$units[$i];
}
function itag($itag){
$stream_itag = array(
"38" =>"3072p",
"85" =>"1080p",
"46" =>"1080p",
"37" =>"1080p",
"102" =>"720p",
"45" =>"720p",
"84" =>"720p",
"22" =>"720p",
"120" =>"720p",
"44" =>"480p",
"35" =>"480p",
"101" =>"360p",
"100" =>"360p",
"43" =>"360p",
"34" =>"360p",
"82" =>"360p",
"18" =>"270p/360p",
"6" =>"270p",
"83" =>"240p",
"13" =>"144p",
"5" =>"240p",
"36" =>"240p",
"17" =>"144p"
);
//return $stream_itag[$itag];
parse_str($itag,$info);

return array(
'iTag' => $stream_itag[$info['itag']],//清晰度
//'Duration' => $info['dur'],//时间
'mt' => $info['expire'],//文件大小
'type' => $info['mime'] //文件形式
);
}

function compress_html_main($buffer){
$initial=strlen($buffer);
$buffer=explode("<!--html-->", $buffer);
$count=count ($buffer);
for ($i = 0; $i <= $count; $i++){
if (stristr($buffer[$i], '<!--html no compression-->')){
$buffer[$i]=(str_replace("<!--html no compression-->", " ", $buffer[$i]));
}else{
$buffer[$i]=(str_replace("\t", " ", $buffer[$i]));
$buffer[$i]=(str_replace("\n\n", "\n", $buffer[$i]));
$buffer[$i]=(str_replace("\n", "", $buffer[$i]));
$buffer[$i]=(str_replace("\r", "", $buffer[$i]));
while (stristr($buffer[$i], ' '))
{
$buffer[$i]=(str_replace(" ", " ", $buffer[$i]));
}
}
$buffer_out.=$buffer[$i];
}
return $buffer_out;
}

function returns($data){
global $ui;
return $ui['callback'] ? $ui['callback']."({$data})" : "Jquery_".bin2hex(base64_encode('sbtencentsbtencent'))."({$data})";
}

$params = [
'url' => VIDEO_URL.VID,
'ajax' => 1,
];

//$_loc1_ = json_decode(api_curl(YouTuBe_Api,$params),true);
$_loc1_ = json_decode(https_curl(YouTuBe_Api,$params,1),true);

preg_match('|<div class="tab-pane fade active in" id="mp4">(.*?)</div> <div class="tab-pane fade" id="mp3">|',compress_html_main($_loc1_['result']),$_loc2_);

preg_match("#data-vlink=\"(.*?)\" .*class=\"video-thumbnail\".* >#",compress_html_main($_loc1_['result']),$_loc3_);//默认播放
preg_match_all("#data-vlink=\"(.*?)\" >#",$_loc2_[1],$_loc4_);//视频链接

//preg_match_all("#</td> <td>(.*?)</td> <td class=\"txt-center\">#",$_loc2_[1],$_loc5_);//视频大小

foreach( $_loc4_[1] as $row ){
$vinfo = itag($row);
$video[] = array(
'url' => $row,
'itag' => $vinfo['iTag'],//清晰度
'mt' => $vinfo['mt'],//文件大小
'type' => $vinfo['type'] //文件形式
);
}
$_loc6_ = itag($_loc3_[1]);
$data = array(
'date' => gmdate("D M d Y h:i:s ")."GMT+0800 (中国标准时间)",
'api' => 'mtop.api.video.url.youtube.get',
'version' => '0.26',
'tip' => 'More than 1080 definition films and audio segmentation are not provided', 
'result' => array(
'default' => array(
'url' => $_loc3_[1],
'itag' => $_loc6_['iTag'],//清晰度
'mt' => $_loc6_['mt'],//文件大小
'type' => $_loc6_['type'] //文件形式
),
'video' => $video,
)
);

//print_r( $_loc4_[1] );
//print_r( compress_html_main($_loc1_['result']) );
print_r( returns(json_encode($data)) );