[PATCH v4 04/24] media: h264: Avoid wrapping long_term_frame_idx

From: Nicolas Dufresne
Date: Tue Apr 26 2022 - 08:58:25 EST


For long term references, frame_num is set to long_term_frame_idx which
does not require wrapping. This is fixed by observation, no directly
related issue have been found yet.

Signed-off-by: Nicolas Dufresne <nicolas.dufresne@xxxxxxxxxxxxx>
Reviewed-by: Sebastian Fricke <sebastian.fricke@xxxxxxxxxxxxx>
Reviewed-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxxxxxxxxx>
---
drivers/media/v4l2-core/v4l2-h264.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/media/v4l2-core/v4l2-h264.c b/drivers/media/v4l2-core/v4l2-h264.c
index 5633a242520a..ac47519a9fbe 100644
--- a/drivers/media/v4l2-core/v4l2-h264.c
+++ b/drivers/media/v4l2-core/v4l2-h264.c
@@ -57,8 +57,10 @@ v4l2_h264_init_reflist_builder(struct v4l2_h264_reflist_builder *b,
* '8.2.4.1 Decoding process for picture numbers' of the spec.
* TODO: This logic will have to be adjusted when we start
* supporting interlaced content.
+ * For long term references, frame_num is set to
+ * long_term_frame_idx which requires no wrapping.
*/
- if (dpb[i].frame_num > cur_frame_num)
+ if (!b->refs[i].longterm && dpb[i].frame_num > cur_frame_num)
b->refs[i].frame_num = (int)dpb[i].frame_num -
max_frame_num;
else
--
2.34.1