Add stream method to identify a video's rotation.

src/FFMpeg/FFProbe/DataMapping/Stream.php

@@ -81,6 +81,24 @@ public function getDimensions()
         return new Dimension($width, $height);
     }
 
+    /**
+     * Returns the rotation of the video stream, in degrees.
+     * Use this to determine if the dimensions are rotated.
+     *
+     * @return Integer
+     *
+     * @throws LogicException   In case the stream is not a video stream.
+     */
+    public function getRotation()
+    {
+      if (!$this->isVideo()) {
+        throw new LogicException('Rotation can only be retrieved from video streams.');
+      }
+      $tags = $this->get('tags');
+      if(empty($tags['rotate'])) return 0;
+      return intval($tags['rotate']);
+    }
+
     /**
      * Extracts a ratio from a string in a \d+:\d+ format given a key name.
      *

tests/Unit/FFProbe/DataMapping/StreamTest.php

@@ -131,4 +131,20 @@ public function providePropertiesForDimensionsExtraction()
             ),
         );
     }
+
+    public function testGetRotationFromVideo()
+    {
+      $stream = new Stream(array(
+          'codec_type' => 'video',
+          'tags' => array()
+      ));
+      $this->assertEquals(0, $stream->getRotation());
+
+      $stream = new Stream(array(
+          'codec_type' => 'video',
+          'tags' => array('rotate' => 90)
+      ));
+      $this->assertEquals(90, $stream->getRotation());
+    }
+
 }