From b1172b8cc615a884d4051517d7356d5842939bb6 Mon Sep 17 00:00:00 2001
From: James Almer <jamrial@gmail.com>
Date: Sun, 22 Jun 2025 10:51:06 -0300
Subject: [PATCH] avcodec/mss2dsp: use FF_PTR_ADD to add offsets to a pointer

Fixes: libavcodec/mss2dsp.c:59:14: runtime error: applying zero offset to null pointer

Tested-by: Kacper Michajlow <kasper93@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>
---
 libavcodec/mss2dsp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/mss2dsp.c b/libavcodec/mss2dsp.c
index cc39dd637f..ace92ef9c7 100644
--- a/libavcodec/mss2dsp.c
+++ b/libavcodec/mss2dsp.c
@@ -56,7 +56,7 @@ static av_always_inline void mss2_blit_wmv9_template(uint8_t *dst,
                 }
             }
         }
-        mask +=  mask_stride;
+        mask  = FF_PTR_ADD(mask, mask_stride);
         dst  +=   dst_stride;
         srcy +=  srcy_stride;
         srcu += srcuv_stride * (r & 1);