Commit 7c06aea6f0 for ffmpeg

commit 7c06aea6f0d26dd70c94ccba6127059cd0a0e352
Author: Ruk Doe <info@doany.io>
Date:   Sat Oct 10 12:04:49 2026 +0900

    avcodec/libaribcaption: allocate one rect in text mode

    aribcaption_trans_text_subtitle() always fills exactly one rect, but
    allocated the rects array with ctx->caption.region_count entries. For a
    caption without regions, such as a clear screen, that is a zero-sized
    allocation, and writing sub->rects[0] goes past its end.

    Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
    Claude-Session: https://claude.ai/code/session_01DdDiDRusmi6eD7qSrKBjHb
    Found-by: Joshua Rogers <joshua.rogers@aisle.com>

diff --git a/libavcodec/libaribcaption.c b/libavcodec/libaribcaption.c
index 03deca7a8b..9bad475f57 100644
--- a/libavcodec/libaribcaption.c
+++ b/libavcodec/libaribcaption.c
@@ -814,7 +814,7 @@ static int aribcaption_trans_text_subtitle(ARIBCaptionContext *ctx)
     int ret = 0;
     const char *text;

-    sub->rects = av_calloc(ctx->caption.region_count, sizeof(*sub->rects));
+    sub->rects = av_calloc(1, sizeof(*sub->rects));
     if (!sub->rects) {
         ret = AVERROR(ENOMEM);
         goto fail;