nextcloud/lib/private/preview/movies.php

<?php
/**
 * Copyright (c) 2013 Frank Karlitschek frank@owncloud.org
 * Copyright (c) 2013 Georg Ehrke georg@ownCloud.com
 * This file is licensed under the Affero General Public License version 3 or
 * later.
 * See the COPYING-README file.
 */
namespace OC\Preview;

function findBinaryPath($program) {
	exec('command -v ' . escapeshellarg($program) . ' 2> /dev/null', $output, $returnCode);
	if ($returnCode === 0 && count($output) > 0) {
		return escapeshellcmd($output[0]);
	}
	return null;
}

// movie preview is currently not supported on Windows
if (!\OC_Util::runningOnWindows()) {
	$isExecEnabled = \OC_Helper::is_function_enabled('exec');
	$ffmpegBinary = null;
	$avconvBinary = null;

	if ($isExecEnabled) {
		$avconvBinary = findBinaryPath('avconv');
		if (!$avconvBinary) {
			$ffmpegBinary = findBinaryPath('ffmpeg');
		}
	}

	if($isExecEnabled && ( $avconvBinary || $ffmpegBinary )) {

		class Movie extends Provider {
			public static $avconvBinary;
			public static $ffmpegBinary;

			public function getMimeType() {
				return '/video\/.*/';
			}

			public function getThumbnail($path, $maxX, $maxY, $scalingup, $fileview) {
				// TODO: use proc_open() and stream the source file ?

				$fileInfo = $fileview->getFileInfo($path);
				$useFileDirectly = (!$fileInfo->isEncrypted() && !$fileInfo->isMounted());

				if ($useFileDirectly) {
					$absPath = $fileview->getLocalFile($path);
				} else {
					$absPath = \OC_Helper::tmpFile();

					$handle = $fileview->fopen($path, 'rb');

					// we better use 5MB (1024 * 1024 * 5 = 5242880) instead of 1MB.
					// in some cases 1MB was no enough to generate thumbnail
					$firstmb = stream_get_contents($handle, 5242880);
					file_put_contents($absPath, $firstmb);
				}

				$result = $this->generateThumbNail($maxX, $maxY, $absPath, 5);
				if ($result === false) {
					$result = $this->generateThumbNail($maxX, $maxY, $absPath, 1);
					if ($result === false) {
						$result = $this->generateThumbNail($maxX, $maxY, $absPath, 0);
					}
				}

				if (!$useFileDirectly) {
					unlink($absPath);
				}

				return $result;
			}

			/**
			 * @param int $maxX
			 * @param int $maxY
			 * @param string $absPath
			 * @param string $tmpPath
			 * @param int $second
			 * @return bool|\OC_Image
			 */
			private function generateThumbNail($maxX, $maxY, $absPath, $second)
			{
				$tmpPath = \OC_Helper::tmpFile();

				if (self::$avconvBinary) {
					$cmd = self::$avconvBinary . ' -an -y -ss ' . escapeshellarg($second) .
						' -i ' . escapeshellarg($absPath) .
						' -f mjpeg -vframes 1 -vsync 1 ' . escapeshellarg($tmpPath) .
						' > /dev/null 2>&1';
				} else {
					$cmd = self::$ffmpegBinary . ' -y -ss ' . escapeshellarg($second) .
						' -i ' . escapeshellarg($absPath) .
						' -f mjpeg -vframes 1' .
						' -s ' . escapeshellarg($maxX) . 'x' . escapeshellarg($maxY) .
						' ' . escapeshellarg($tmpPath) .
						' > /dev/null 2>&1';
				}

				exec($cmd, $output, $returnCode);

				if ($returnCode === 0) {
					$image = new \OC_Image();
					$image->loadFromFile($tmpPath);
					unlink($tmpPath);
					return $image->valid() ? $image : false;
				}
				unlink($tmpPath);
				return false;
			}
		}

		// a bit hacky but didn't want to use subclasses
		Movie::$avconvBinary = $avconvBinary;
		Movie::$ffmpegBinary = $ffmpegBinary;

		\OC\Preview::registerProvider('OC\Preview\Movie');
	}
}