From acc69e082fff67398834de3045ef48d33d2f4d54 Mon Sep 17 00:00:00 2001
From: Mike Will <myQwil@gmail.com>
Date: Wed, 7 Aug 2024 15:59:28 -0400
Subject: [PATCH] img_format: prevent an offset >= MP_MAX_PLANES into bpp

Addresses the warning: "writing 1 byte into a region of size 0"
---
 video/img_format.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/video/img_format.c b/video/img_format.c
index c9e2a3c0e6..20e23a9eb0 100644
--- a/video/img_format.c
+++ b/video/img_format.c
@@ -399,7 +399,8 @@ fail:
     for (int n = 0; n < 4; n++)
         desc->comps[n] = (struct mp_imgfmt_comp_desc){0};
     // Average bit size fallback.
-    desc->num_planes = av_pix_fmt_count_planes(fmt);
+    int num_planes = av_pix_fmt_count_planes(fmt);
+    desc->num_planes = MPCLAMP(num_planes, 0, MP_MAX_PLANES);
     for (int p = 0; p < desc->num_planes; p++) {
         int ls = av_image_get_linesize(fmt, 256, p);
         desc->bpp[p] = ls > 0 ? ls * 8 / 256 : 0;