Commit 4b0fad0c61 for ffmpeg

commit 4b0fad0c61a9ba93e7bc8a469dac8ff208a45d7b
Author: Baptiste Coudurier <baptiste.coudurier@gmail.com>
Date:   Thu Nov 12 13:40:38 2026 -0800

    avcodec/svq1dec: set the key flag on intra frames

    Intra frames are self-contained and were only marked as
    AV_PICTURE_TYPE_I, so every decoded SVQ1 frame had key_frame=0 and
    players waiting for a keyframe never showed the video.

    Fixes #25938.

    Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
    Signed-off-by: Baptiste Coudurier <baptiste.coudurier@gmail.com>

diff --git a/libavcodec/svq1dec.c b/libavcodec/svq1dec.c
index c1927d7d3b..9a78c34fc1 100644
--- a/libavcodec/svq1dec.c
+++ b/libavcodec/svq1dec.c
@@ -555,6 +555,7 @@ static int svq1_decode_frame_header(AVCodecContext *avctx, AVFrame *frame, int *
     switch (get_bits(bitbuf, 2)) {
     case 0:
         frame->pict_type = AV_PICTURE_TYPE_I;
+        frame->flags    |= AV_FRAME_FLAG_KEY;
         break;
     case 2:
         s->nonref = 1;