<?php

	class Mediainfo {

		var $xml, $audiobitrate, $videobitrate, $audiochannels, $duration, $width, $height, $audiocodec, $videocodec;

		function Mediainfo($source) {

			// May need full path to mediainfo, usually /usr/bin/mediainfo
			$this->xml = new SimpleXMLElement(shell_exec('mediainfo --output=XML '. $source));
			$this->parse();
		} 

		function parse() {

			foreach ($this->xml->File->track as $track) {

				$type = strtolower($track['type']);
				$bitrate = $track->Bit_rate;
				$bitrate = (int)substr($bitrate,0,strpos($bitrate,' '));
				$bitrate = $bitrate * 1000;

				switch ($type) {

					case 'general':
						// Get duration in seconds
						preg_match_all('/\d+/', $this->xml->File->track[0]->Duration, $matches);
						if (count($matches) == 1)
							$this->duration = $matches[0];
						if (count($matches) == 2)
							$this->duration = $matches[0] * 60 + $matches[1];
						if (count($matches) == 3)
							$this->duration = $matches[0] * 60 * 60 + $matches[1] * 60 + $matches[2];
						break;
					case 'video':
						// Get some details from the video stream
						$this->videobitrate = $bitrate;
						$this->height = $track->Height;
						$this->width = $track->Width;
						$this->videocodec = strtolower($track->Format);
						break;
					case 'audio':
						// Audio stream - If there's many and they differ then the last one is chosen.
						$this->audiobitrate = $bitrate;
						preg_match('/\d+/', $track->Channel_s_, $matches);
						$this->audiochannels = $matches[0];
						$this->audiocodec = strtolower($track->Format);
						break;
				}
			}

			if ($this->audiobitrate == null) $this->audiobitrate = 0;
			if ($this->audiochannels == null) $this->audiochannels = 0;
		}
	}

	function CreateVideo($videoFile) {

		$mediainfo = new Mediainfo($videoFile);
		$videobitrate = $mediainfo->videobitrate;
		$audiobitrate = $mediainfo->audiobitrate;
		$audiochannels = $mediainfo->audiochannels;

		$width = $mediainfo->width;
		$height = $mediainfo->height;

		$pcmd = "ffmpeg -i " . $videoFile;

		if ($height >= 720) {

			$pcmd .= " -vf ";

			if ($height == 1088) {
				$pcmd .= "crop=iw:1080:x:y,";
			}

			$pcmd .= 'scale="trunc(oh*in_w/in_h/2)*2:720"';
			$width = (float)(720 * $width) / $height;
		} 

		// Bitrate depending on bitrate of input
		if ($width <= 320)
			$vbitrate = $videobitrate >= 310000 ? "300" : null;
		else if ($width <= 480)
			$vbitrate = $videobitrate >= 510000 ? "500" : null;
		else if ($width <= 640)
			$vbitrate = $videobitrate >= 710000 ? "700" : null;
		else if ($width <= 900)
			$vbitrate = $videobitrate >= 810000 ? "800" : null;
		else if ($width <= 1280)
			$vbitrate = $videobitrate >= 1010000 ? "1000" : null;
		else
			$vbitrate = $videobitrate >= 1210000 ? "1200" : null;

		// If source codec is h264 then we don't need to change it.
		if ($mediainfo->videocodec == "h264" && empty($vbitrate)) {
			$pcmd .= " -vcodec copy";
		} else {

			$pcmd .= " -vcodec libx264 -r 29.97 -g 160 -cmp 2 -subcmp 2 -mbd 2 -flags +aic+cbp+mv0+mv4 -trellis 1";

			if (!empty($vbitrate)) {
				$pcmd .= " -b:v ${vbitrate}k";
			} else {
				$pcmd .= " -b:v ${videobitrate}";
			}
		}
     
		// Same as before - Don't reencode audio if it's already AAC and less than 96k
		if ($mediainfo->audiocodec == "aac" && $audiobitrate <= 96000) {
			$pcmd .= " -acodec copy";
		} else {
			if ($audiobitrate > 96000) $audiobitrate = 96000;
			// if ($audiochannels == 1) $audiobitrate /= 2;
			$pcmd .= " -acodec aac -strict experimental -ac " . $audiochannels . " -ar 44100 -ab " . $audiobitrate;
		}

		// $pcmd .= " ".$this->ffmpeg_extra;

		$pcmd .= " -y ./video.mp4";
		echo $pcmd;
     
		//if(run($pcmd) != 0) throw new Exception("FFmpeg error: ".$flvname, posix_get_last_error());
     
		// MP4Box available in gpac package in debian (May need another repo, can't remember)
		$pcmd = sprintf("MP4Box -inter 3000 video.mp4 -out video_new.mp4");
     
		echo $pcmd;
		//if(run($pcmd) != 0) throw new Exception("MP4Box error: ".$flvname, posix_get_last_error());
	}

$_POST['filename'] = "test/data/test3.mp4";

	CreateVideo($_POST['filename']);