From b5391a5fc9049addae418073393765703ecbbf9a Mon Sep 17 00:00:00 2001
From: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
Date: Mon, 17 Mar 2025 09:53:42 +0100
Subject: [PATCH 1/3] avcodec/h261enc: Don't use (size_t)-1
Fixes "runtime error: addition of unsigned offset to 0x765a09523a90
overflowed to 0x765a09523a8e". This fixes all H.261 tests when run
under UBsan.
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
---
libavcodec/h261enc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/libavcodec/h261enc.c b/libavcodec/h261enc.c
index 36436ee60f..5e6d5d1f9c 100644
--- a/libavcodec/h261enc.c
+++ b/libavcodec/h261enc.c
@@ -337,7 +337,7 @@ static av_cold void h261_encode_init_static(void)
uni_h261_rl_len_last[UNI_AC_ENC_INDEX(run, 64 - level)] = len + 2;
}
- for (size_t i = 1;; i++) {
+ for (ptrdiff_t i = 1;; i++) {
// sign-one MV codes; diff -16..-1, 16..31
mv_codes[32 - i][0] = mv_codes[-i][0] = (ff_h261_mv_tab[i][0] << 1) | 1 /* sign */;
mv_codes[32 - i][1] = mv_codes[-i][1] = ff_h261_mv_tab[i][1] + 1;
--
2.45.2