From 71adb740591ea0b604d41bab3c69786cdb9be99e Mon Sep 17 00:00:00 2001
From: Nicolas George <nicolas.george@normalesup.org>
Date: Tue, 14 Aug 2012 18:50:23 +0200
Subject: [PATCH] vf_tinterlace: leave harmless permissions alone.

---
 libavfilter/vf_tinterlace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavfilter/vf_tinterlace.c b/libavfilter/vf_tinterlace.c
index 559f64b25b..5b03b81bf1 100644
--- a/libavfilter/vf_tinterlace.c
+++ b/libavfilter/vf_tinterlace.c
@@ -294,7 +294,7 @@ static int end_frame(AVFilterLink *inlink)
         break;
     case MODE_INTERLACEX2: /* re-interlace preserving image height, double frame rate */
         /* output current frame first */
-        out = avfilter_ref_buffer(cur, AV_PERM_READ);
+        out = avfilter_ref_buffer(cur, ~AV_PERM_WRITE);
         out->video->interlaced = 1;
 
         ff_start_frame(outlink, out);