Add a rotate filter (fix #15)

src/FFMpeg/Filters/Video/RotateFilter.php

@@ -0,0 +1,73 @@
+<?php
+
+/*
+ * This file is part of PHP-FFmpeg.
+ *
+ * (c) Alchemy <dev.team@alchemy.fr>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace FFMpeg\Filters\Video;
+
+use FFMpeg\Coordinate\Dimension;
+use FFMpeg\Exception\InvalidArgumentException;
+use FFMpeg\Exception\RuntimeException;
+use FFMpeg\Media\Video;
+use FFMpeg\Format\VideoInterface;
+
+class RotateFilter implements VideoFilterInterface
+{
+    const ROTATE_90 = 'transpose=1';
+    const ROTATE_180 = 'hflip,vflip';
+    const ROTATE_270 = 'transpose=2';
+
+    /** @var string */
+    private $angle;
+    /** @var integer */
+    private $priority;
+
+    public function __construct($angle, $priority = 0)
+    {
+        $this->setAngle($angle);
+        $this->priority = (int) $priority;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function getPriority()
+    {
+        return $this->priority;
+    }
+
+    /**
+     * @return Dimension
+     */
+    public function getAngle()
+    {
+        return $this->angle;
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function apply(Video $video, VideoInterface $format)
+    {
+        return array('-vf', $this->angle, '-metadata:s:v:0', 'rotate=0');
+    }
+
+    private function setAngle($angle)
+    {
+        switch ($angle) {
+            case self::ROTATE_90:
+            case self::ROTATE_180:
+            case self::ROTATE_270:
+                $this->angle = $angle;
+                break;
+            default:
+                throw new InvalidArgumentException('Invalid angle value.');
+        }
+    }
+}

src/FFMpeg/Filters/Video/VideoFilters.php

@@ -95,4 +95,11 @@ class VideoFilters extends AudioFilters
 
         return $this;
     }
+
+    public function rotate($angle, $priority = 0)
+    {
+        $this->media->addFilter(new RotateFilter($angle, $priority));
+
+        return $this;
+    }
 }