I am trying to upload a video to Youtube using PHP. I am using Youtube API v3 and I am using the latest checked out source code of Google API PHP Client library.
I am using the sample code given on
https://code.google.com/p/google-api-php-client/ to perform the authentication. The authentication goes through fine but when I try to upload a video I get Google_ServiceException with error code 500 and message as null. 
I had a look at the following question asked earlier:
Upload video to youtube using php client library v3 But the accepted answer doesn't describe how to specify file data to be uploaded.
I found another similar question Uploading file with Youtube API v3 and PHP, where in the comment it is mentioned that categoryId is mandatory, hence I tried setting the categoryId in the snippet but still it gives the same exception.
I also referred to the Python code on the the documentation site ( https://developers.google.com/youtube/v3/docs/videos/insert ), but I couldn't find the function next_chunk in the client library. But I tried to put a loop (mentioned in the code snippet) to retry on getting error code 500, but in all 10 iterations I get the same error.
Following is the code snippet I am trying:
$youTubeService = new Google_YoutubeService($client);
if ($client->getAccessToken()) {
    print "Successfully authenticated";
    $snippet = new Google_VideoSnippet();
    $snippet->setTitle = "My Demo title";
    $snippet->setDescription = "My Demo descrition";
    $snippet->setTags = array("tag1","tag2");
    $snippet->setCategoryId(23); // this was added later after refering to another question on stackoverflow
    $status = new Google_VideoStatus();
    $status->privacyStatus = "private";
    $video = new Google_Video();
    $video->setSnippet($snippet);
    $video->setStatus($status);
    $data = file_get_contents("video.mp4"); // This file is present in the same directory as the code
    $mediaUpload = new Google_MediaFileUpload("video/mp4",$data);
    $error = true;
    $i = 0;
    // I added this loop because on the sample python code on the documentation page
    // mentions we should retry if we get error codes 500,502,503,504
    $retryErrorCodes = array(500, 502, 503, 504);
    while($i < 10 && $error) {
        try{
            $ret = $youTubeService->videos->insert("status,snippet", 
                                                   $video, 
                                                   array("data" => $data));
            // tried the following as well, but even this returns error code 500,
            // $ret = $youTubeService->videos->insert("status,snippet", 
            //                                        $video, 
            //                                        array("mediaUpload" => $mediaUpload); 
            $error = false;
        } catch(Google_ServiceException $e) {
            print "Caught Google service Exception ".$e->getCode()
                  . " message is ".$e->getMessage();
            if(!in_array($e->getCode(), $retryErrorCodes)){
                break;
            }
            $i++;
        }
    }
    print "Return value is ".print_r($ret,true);
    // We're not done yet. Remember to update the cached access token.
    // Remember to replace $_SESSION with a real database or memcached.
    $_SESSION['token'] = $client->getAccessToken();
} else {
    $authUrl = $client->createAuthUrl();
    print "<a href='$authUrl'>Connect Me!</a>";
}
Is it something that I am doing wrong?
 
     
     
     
    