Source of file SupportedSite.php

<?php

namespace AudioDidact\SupportedSites;

abstract class SupportedSite {

	/** @var \AudioDidact\Video local video object */

	protected $video;

	public static function supportsURL($url){

		return false;

	}

	/**

	 * Get duration of media file from ffmpeg

	 *

	 * @param $file

	 * @return bool|string

	 */

	public static function getDuration($file){

		$dur = shell_exec("ffmpeg -i " . $file . " 2>&1");

		if(preg_match("/: Invalid /", $dur)){

			return false;

		}

		preg_match("/Duration: (.{2}):(.{2}):(.{2})/", $dur, $duration);

		if(!isset($duration[1])){

			return false;

		}

		return $duration[1] . ":" . $duration[2] . ":" . $duration[3];

	}

	/**

	 * Get duration in seconds of media file from ffmpeg

	 *

	 * @param $file

	 * @return bool|string

	 */

	public static function getDurationSeconds($file){

		$dur = shell_exec("ffmpeg -i " . $file . " 2>&1");

		if(preg_match("/: Invalid /", $dur)){

			return false;

		}

		preg_match("/Duration: (.{2}):(.{2}):(.{2})/", $dur, $duration);

		if(!isset($duration[1])){

			return false;

		}

		$hours = $duration[1];

		$minutes = $duration[2];

		$seconds = $duration[3];

		return $seconds + ($minutes * 60) + ($hours * 60 * 60);

	}

	/**

	 * Checks if all thumbnail, video, and mp3 are downloaded and have a length (ie. video or audio are not null)

	 *

	 * @param \AudioDidact\Video $vid

	 * @return bool

	 */

	public static function allDownloadedVideo(\AudioDidact\Video $vid){

		$downloadPath = DOWNLOAD_PATH . DIRECTORY_SEPARATOR;

		$downloadFilePath = $downloadPath . $vid->getFilename();

		$fullDownloadPath = $downloadFilePath . $vid->getFileExtension();

		if($vid->isIsVideo() && file_exists($fullDownloadPath) && SupportedSite::getDuration($fullDownloadPath)){

			// If only the mp4 is downloaded (and has a duration)

			$vid->setDuration(SupportedSite::getDurationSeconds($fullDownloadPath));

			return true;

		}

		else if(file_exists($downloadFilePath . ".mp3") &&

			file_exists($downloadFilePath . ".mp4") &&

			SupportedSite::getDuration($downloadFilePath . ".mp3") &&

			abs(SupportedSite::getDurationSeconds($downloadFilePath . ".mp4") - SupportedSite::getDurationSeconds

			($downloadFilePath . ".mp3")) <= 5

		){

			// Before returning true, set the duration since convert will not be run

			$vid->setDuration(SupportedSite::getDurationSeconds($fullDownloadPath));

			return true;

		}

		// If all else fails, return false

		return false;

	}

	public function allDownloaded(){

		// If the thumbnail has not been downloaded, go ahead and download it

		if(!file_exists(DOWNLOAD_PATH . DIRECTORY_SEPARATOR . $this->video->getThumbnailFilename())){

			$this->downloadThumbnail();

		}

		return static::allDownloadedVideo($this->video);

	}

	abstract public function downloadThumbnail();

	abstract public function downloadVideo();

	public function applyArt(){

		$path = getcwd() . DIRECTORY_SEPARATOR . DOWNLOAD_PATH . DIRECTORY_SEPARATOR;

		$ffmpegAlbumArt = $path . $this->video->getThumbnailFilename();

		$ffmpegOutFile = $path . $this->video->getFilename() . $this->video->getFileExtension();

		$ffmpegTempFile = $path . $this->video->getFilename() . "-art.mp3";

		exec("ffmpeg -i \"$ffmpegOutFile\" -i \"$ffmpegAlbumArt\" -y -c copy -map 0 -map 1 -id3v2_version 3 -metadata:s:v title=\"Album cover\" -metadata:s:v comment=\"Cover (Front)\"  \"$ffmpegTempFile\" 2>&1");

		rename($ffmpegTempFile, $ffmpegOutFile);

		$this->video->setDuration(SupportedSite::getDurationSeconds($ffmpegOutFile));

		return;

	}

	/**

	 * Converts mp4 video to mp3 audio using ffmpeg

	 */

	public function convert(){

		$path = getcwd() . DIRECTORY_SEPARATOR . DOWNLOAD_PATH . DIRECTORY_SEPARATOR;

		$ffmpegInFile = $path . $this->video->getFilename() . ".mp4";

		$ffmpegOutFile = $path . $this->video->getFilename() . $this->video->getFileExtension();

		// Use ffmpeg to convert the audio in the background and save output to a file called videoID.txt

		$cmd = "ffmpeg -i \"$ffmpegInFile\" -y -q:a 5 -map a \"$ffmpegOutFile\" > " . $this->video->getID() . ".txt 2>&1";

		// Check if we're on Windows or *nix

		if(strtoupper(mb_substr(PHP_OS, 0, 3)) === 'WIN'){

			// Start the command in the background

			pclose(popen("start /B " . $cmd, "r"));

		}

		else{

			pclose(popen($cmd . " &", "r"));

		}

		$progress = 0;

		// Get the conversion progress and output the progress to the UI using a JSON array

		while($progress != 100){

			$content = @file_get_contents($this->video->getID() . '.txt');

			// Get the total duration of the file

			preg_match("/Duration: (.*?), start:/", $content, $matches);

			// If there is no match, then wait and continue

			if(!isset($matches[1])){

				usleep(500000);

				continue;

			}

			$rawDuration = $matches[1];

			$ar = array_reverse(explode(":", $rawDuration));

			$duration = floatval($ar[0]);

			if(!empty($ar[1])){

				$duration += intval($ar[1]) * 60;

			}

			if(!empty($ar[2])){

				$duration += intval($ar[2]) * 60 * 60;

			}

			preg_match_all("/time=(.*?) bitrate/", $content, $matches);

			// Matches time of the converted file and gets the percentage complete

			$rawTime = array_pop($matches);

			if(is_array($rawTime)){

				$rawTime = array_pop($rawTime);

			}

			$ar = array_reverse(explode(":", $rawTime));

			$time = floatval($ar[0]);

			if(!empty($ar[1])){

				$time += intval($ar[1]) * 60;

			}

			if(!empty($ar[2])){

				$time += intval($ar[2]) * 60 * 60;

			}

			$progress = round(($time / $duration) * 100);

			// Send progress to UI

			$response = ['stage' => 1, 'progress' => $progress];

			echo json_encode($response);

			usleep(500000);

		}

		// Delete the temporary file that contained the ffmpeg output

		@unlink($this->video->getID() . ".txt");

		return $ffmpegOutFile;

	}

	/**

	 * Download the video to $localFile with a given $url

	 * While downloading output progress to UI as JSON array

	 *

	 * @param $url

	 * @param $localFile

	 * @return bool

	 * @throws \Exception

	 */

	protected function downloadWithPercentage($url, $localFile){

		// Use CURL to get the download content length in order to print the progress

		$ch = curl_init($url);

		curl_setopt($ch, CURLOPT_NOBODY, true);

		curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

		curl_setopt($ch, CURLOPT_HEADER, true);

		curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);

		curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);

		$data = curl_exec($ch);

		if($data === false){

			throw new \Exception("Download failed, URL tried was " . $url . "\ncURL error (" . curl_errno($ch) . "): "

				. curl_error($ch));

		}

		curl_close($ch);

		// Get content length in bytes

		$contentLength = 'unknown';

		if(preg_match_all('/Content-Length: (\d+)/', $data, $matches)){

			$contentLength = (int)$matches[count($matches) - 1][count($matches[count($matches) - 1]) - 1];

		}

		if(intval($contentLength) > 0){

			// Open local and remote files for write and read respectively

			$remote = fopen($url, 'r');

			$local = fopen($localFile, 'w');

			$readBytes = 0;

			// Read until the end of the remote file

			while(!feof($remote)){

				// Read 4KB and write them to the local file

				$buffer = fread($remote, 4096);

				fwrite($local, $buffer);

				$readBytes += 4096;

				// Get progress percentage from the read bytes and total length

				$progress = min(100, 100 * $readBytes / $contentLength);

				// Print progress to the UI using a JSON array

				$response = ['stage' => 0, 'progress' => $progress];

				echo json_encode($response);

			}

			// Close the handles of both files

			fclose($remote);

			fclose($local);

		}

		else{

			error_log("Content length was 0 for URL: " . $url);

			throw new \Exception("Downloaded file length was 0, please try again later");

		}

		return true;

	}

	/**

	 * Returns the current Video object

	 *

	 * @return \AudioDidact\Video

	 */

	public function getVideo(){

		return $this->video;

	}

	public static function echoErrorJSON($message){

		echo json_encode(['stage' => -1, 'progress' => 0, 'error' => $message]);

	}

}