1 files changed, 152 insertions, 0 deletions
diff --git a/lib/private/Preview/HEIC.php b/lib/private/Preview/HEIC.php
new file mode 100644
index 00000000000..64eb48e58df
--- /dev/null
+++ b/lib/private/Preview/HEIC.php
@@ -0,0 +1,152 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2018 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-FileCopyrightText: 2018 ownCloud GmbH
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+namespace OC\Preview;
+
+use OCP\Files\File;
+use OCP\Files\FileInfo;
+use OCP\IImage;
+use OCP\Server;
+use Psr\Log\LoggerInterface;
+
+/**
+ * Creates a JPG preview using ImageMagick via the PECL extension
+ *
+ * @package OC\Preview
+ */
+class HEIC extends ProviderV2 {
+	/**
+	 * {@inheritDoc}
+	 */
+	public function getMimeType(): string {
+		return '/image\/(x-)?hei(f|c)/';
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function isAvailable(FileInfo $file): bool {
+		return in_array('HEIC', \Imagick::queryFormats('HEI*'));
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	public function getThumbnail(File $file, int $maxX, int $maxY): ?IImage {
+		if (!$this->isAvailable($file)) {
+			return null;
+		}
+
+		$tmpPath = $this->getLocalFile($file);
+		if ($tmpPath === false) {
+			Server::get(LoggerInterface::class)->error(
+				'Failed to get local file to generate thumbnail for: ' . $file->getPath(),
+				['app' => 'core']
+			);
+			return null;
+		}
+
+		// Creates \Imagick object from the heic file
+		try {
+			$bp = $this->getResizedPreview($tmpPath, $maxX, $maxY);
+			$bp->setFormat('jpg');
+		} catch (\Exception $e) {
+			\OC::$server->get(LoggerInterface::class)->error(
+				'File: ' . $file->getPath() . ' Imagick says:',
+				[
+					'exception' => $e,
+					'app' => 'core',
+				]
+			);
+			return null;
+		}
+
+		$this->cleanTmpFiles();
+
+		//new bitmap image object
+		$image = new \OCP\Image();
+		$image->loadFromData((string)$bp);
+		//check if image object is valid
+		return $image->valid() ? $image : null;
+	}
+
+	/**
+	 * Returns a preview of maxX times maxY dimensions in JPG format
+	 *
+	 *    * The default resolution is already 72dpi, no need to change it for a bitmap output
+	 *    * It's possible to have proper colour conversion using profileimage().
+	 *    ICC profiles are here: http://www.color.org/srgbprofiles.xalter
+	 *    * It's possible to Gamma-correct an image via gammaImage()
+	 *
+	 * @param string $tmpPath the location of the file to convert
+	 * @param int $maxX
+	 * @param int $maxY
+	 *
+	 * @return \Imagick
+	 *
+	 * @throws \Exception
+	 */
+	private function getResizedPreview($tmpPath, $maxX, $maxY) {
+		$bp = new \Imagick();
+
+		// Some HEIC files just contain (or at least are identified as) other formats
+		// like JPEG. We just need to check if the image is safe to process.
+		$bp->pingImage($tmpPath . '[0]');
+		$mimeType = $bp->getImageMimeType();
+		if (!preg_match('/^image\/(x-)?(png|jpeg|gif|bmp|tiff|webp|hei(f|c)|avif)$/', $mimeType)) {
+			throw new \Exception('File mime type does not match the preview provider: ' . $mimeType);
+		}
+
+		// Layer 0 contains either the bitmap or a flat representation of all vector layers
+		$bp->readImage($tmpPath . '[0]');
+
+		// Fix orientation from EXIF
+		$bp->autoOrient();
+
+		$bp->setImageFormat('jpg');
+
+		$bp = $this->resize($bp, $maxX, $maxY);
+
+		return $bp;
+	}
+
+	/**
+	 * Returns a resized \Imagick object
+	 *
+	 * If you want to know more on the various methods available to resize an
+	 * image, check out this link : @link https://stackoverflow.com/questions/8517304/what-the-difference-of-sample-resample-scale-resize-adaptive-resize-thumbnail-im
+	 *
+	 * @param \Imagick $bp
+	 * @param int $maxX
+	 * @param int $maxY
+	 *
+	 * @return \Imagick
+	 */
+	private function resize($bp, $maxX, $maxY) {
+		[$previewWidth, $previewHeight] = array_values($bp->getImageGeometry());
+
+		// We only need to resize a preview which doesn't fit in the maximum dimensions
+		if ($previewWidth > $maxX || $previewHeight > $maxY) {
+			// If we want a small image (thumbnail) let's be most space- and time-efficient
+			if ($maxX <= 500 && $maxY <= 500) {
+				$bp->thumbnailImage($maxY, $maxX, true);
+				$bp->stripImage();
+			} else {
+				// A bigger image calls for some better resizing algorithm
+				// According to http://www.imagemagick.org/Usage/filter/#lanczos
+				// the catrom filter is almost identical to Lanczos2, but according
+				// to https://www.php.net/manual/en/imagick.resizeimage.php it is
+				// significantly faster
+				$bp->resizeImage($maxX, $maxY, \Imagick::FILTER_CATROM, 1, true);
+			}
+		}
+
+		return $bp;
+	}
+}