From 30400f0d03f080c5880ba6c1e728ca35264abd8f Mon Sep 17 00:00:00 2001
From: Baptiste Coudurier <baptiste.coudurier@gmail.com>
Date: Thu, 6 Mar 2008 09:45:59 +0000
Subject: [PATCH] fix interlaced decoding, original patch from reimar

Originally committed as revision 12349 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavcodec/gifdec.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/libavcodec/gifdec.c b/libavcodec/gifdec.c
index 8f0252694b..d8f67b4640 100644
--- a/libavcodec/gifdec.c
+++ b/libavcodec/gifdec.c
@@ -126,11 +126,8 @@ static int gif_read_image(GifState *s)
                 y1 += 8;
                 ptr += linesize * 8;
                 if (y1 >= height) {
-                    y1 = 4;
-                    if (pass == 0)
-                        ptr = ptr1 + linesize * 4;
-                    else
-                        ptr = ptr1 + linesize * 2;
+                    y1 = pass ? 2 : 4;
+                    ptr = ptr1 + linesize * y1;
                     pass++;
                 }
                 break;