From 0c4ec68f554996b4321cd0c0c6a80d9b6c9df321 Mon Sep 17 00:00:00 2001
From: Carl Hetherington <cth@carlh.net>
Date: Sun, 21 May 2017 23:18:57 +0100
Subject: [PATCH] Fix _position with VIDEO_FRAME_TYPE_3D_ALTERNATE.

---
 src/lib/video_decoder.cc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/lib/video_decoder.cc b/src/lib/video_decoder.cc
index 9afbd31c4..eb5d2e71f 100644
--- a/src/lib/video_decoder.cc
+++ b/src/lib/video_decoder.cc
@@ -76,6 +76,7 @@ VideoDecoder::emit (shared_ptr<const ImageProxy> image, Frame frame)
 	}
 	case VIDEO_FRAME_TYPE_3D_ALTERNATE:
 		Data (ContentVideo (image, frame / 2, (frame % 2) ? EYES_RIGHT : EYES_LEFT, PART_WHOLE));
+		frame /= 2;
 		break;
 	case VIDEO_FRAME_TYPE_3D_LEFT_RIGHT:
 		Data (ContentVideo (image, frame, EYES_LEFT, PART_LEFT_HALF));
-- 
2.30.2