Commit 1080be2816 for ffmpeg

commit 1080be28164859f1ea6191c9cb304e1a2b2cb633
Author: zhang xingxing <2388969553@qq.com>
Date:   Fri Nov 6 02:08:08 2026 +0100

    avcodec/jpeg2000_parser: fix the tile-part length check

    This is not a security issue.

    Fixes: integer underflow
    Fixes: kgusFCuY3WYo
    Fixes: swarm-Unsigned-arithmetic-underflow-in-tile-part-skip_bytes-calculation-d23292

    Found-by: zhang xingxing <2388969553@qq.com>

    Merged frames Replicated through UnModified FFmpeg with ffprobe

    Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

diff --git a/libavcodec/jpeg2000_parser.c b/libavcodec/jpeg2000_parser.c
index a5dcc9c9f1..edf47934d5 100644
--- a/libavcodec/jpeg2000_parser.c
+++ b/libavcodec/jpeg2000_parser.c
@@ -122,7 +122,7 @@ static int find_frame_end(JPEG2000ParserContext *m, const uint8_t *buf, int buf_
         }
         if (m->read_tp) { // Find out how many bytes inside Tile part codestream to skip.
             if (m->read_tp == 1) {
-                m->skip_bytes = (state64 & 0xFFFFFFFF) - 9 > 0?
+                m->skip_bytes = (state64 & 0xFFFFFFFF) > 9 ?
                                 (state64 & 0xFFFFFFFF) - 9 : 0;
             }
             m->read_tp--;