On 10/11/2024 12:13, Nuo Mi wrote:
> This commit introduced a regression to
> VVC_HDR_UHDTV1_OpenGOP_3840x2160_50fps_HLG10_mosaic.ts.
>
> Root Cause:
> The AV_CEIL_RSHIFT(a, b) macro uses bit tricks that work only when -a is a
> negative value.
> However, due to integer promotion rules, this behavior does not extend to the
> unsigned int type.
>
> See "6.3.1.1 Boolean, characters, and integers" in the "ISO/IEC 9899" for
> details.
>
> Reported-by: Frank Plowman <p...@frankplowman.com>
> ---
> libavcodec/cbs_h266_syntax_template.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/libavcodec/cbs_h266_syntax_template.c
> b/libavcodec/cbs_h266_syntax_template.c
> index b21d07491b..6b2d6534ef 100644
> --- a/libavcodec/cbs_h266_syntax_template.c
> +++ b/libavcodec/cbs_h266_syntax_template.c
> @@ -1162,7 +1162,7 @@ static int FUNC(sps)(CodedBitstreamContext *ctx,
> RWContext *rw,
> for (i = 1; i <= current->sps_num_subpics_minus1; i++) {
> if (!current->sps_subpic_same_size_flag) {
> if (current->sps_pic_width_max_in_luma_samples >
> ctb_size_y) {
> - const unsigned int win_right_edge =
> + const int win_right_edge =
> current->sps_pic_width_max_in_luma_samples
> - current->sps_conf_win_right_offset * sub_width_c;
> us(wlen, sps_subpic_ctu_top_left_x[i], 0,
> @@ -1172,7 +1172,7 @@ static int FUNC(sps)(CodedBitstreamContext *ctx,
> RWContext *rw,
> infer(sps_subpic_ctu_top_left_x[i], 0);
> if (current->sps_pic_height_max_in_luma_samples >
> ctb_size_y) {
> - const unsigned int win_bottom_edge =
> + const int win_bottom_edge =
> current->sps_pic_height_max_in_luma_samples
> - current->sps_conf_win_bottom_offset *
> sub_height_c;
> us(hlen, sps_subpic_ctu_top_left_y[i], 0,
> @@ -1183,9 +1183,9 @@ static int FUNC(sps)(CodedBitstreamContext *ctx,
> RWContext *rw,
> if (i < current->sps_num_subpics_minus1 &&
> current->sps_pic_width_max_in_luma_samples >
> ctb_size_y) {
> - const unsigned int win_left_edge =
> + const int win_left_edge =
> current->sps_conf_win_left_offset * sub_width_c;
> - const unsigned int win_left_edge_ctus =
> + const int win_left_edge_ctus =
> AV_CEIL_RSHIFT(win_left_edge, ctb_log2_size_y);
> us(wlen, sps_subpic_width_minus1[i],
> win_left_edge_ctus >
> current->sps_subpic_ctu_top_left_x[i]
> @@ -1200,9 +1200,9 @@ static int FUNC(sps)(CodedBitstreamContext *ctx,
> RWContext *rw,
> if (i < current->sps_num_subpics_minus1 &&
> current->sps_pic_height_max_in_luma_samples >
> ctb_size_y) {
> - const unsigned int win_top_edge =
> + const int win_top_edge =
> current->sps_conf_win_top_offset * sub_height_c;
> - const unsigned int win_top_edge_ctus =
> + const int win_top_edge_ctus =
> AV_CEIL_RSHIFT(win_top_edge, ctb_log2_size_y);
> us(hlen, sps_subpic_height_minus1[i],
> win_top_edge_ctus >
> current->sps_subpic_ctu_top_left_y[i]
LGTM!
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