[FFmpeg-devel] [PATCH 1/2] avcodec/cbs_h265: fix valid range of num_tile_{columns, rows}_minus1 in H265RawPPS

[Gyan]

On 20-06-2019 11:15 PM, James Almer wrote:
> The spec states they can't be higher than the respective dimensions of the
> stream in CTBs.
>
> Signed-off-by: James Almer <jamrial at gmail.com>
> ---
> I don't think it's wise further limiting the range to the maximum currently
> defined for level 6.2 using those two HEVC_ defines, since a stream could in
> theory go beyond them (New levels defined in the future?), but the alternative
> is making the column_width_minus1 and row_height_minus1 arrays much bigger, or
> dinamically allocated.
dinamically--> dynamically

>
>   libavcodec/cbs_h265_syntax_template.c | 13 +++++++++++--
>   1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/libavcodec/cbs_h265_syntax_template.c b/libavcodec/cbs_h265_syntax_template.c
> index f279d283d9..d2a20ddb35 100644
> --- a/libavcodec/cbs_h265_syntax_template.c
> +++ b/libavcodec/cbs_h265_syntax_template.c
> @@ -1045,8 +1045,17 @@ static int FUNC(pps)(CodedBitstreamContext *ctx, RWContext *rw,
>       flag(entropy_coding_sync_enabled_flag);
>   
>       if (current->tiles_enabled_flag) {
> -        ue(num_tile_columns_minus1, 0, HEVC_MAX_TILE_COLUMNS);
> -        ue(num_tile_rows_minus1,    0, HEVC_MAX_TILE_ROWS);
> +        unsigned int min_cb_log2_size_y = sps->log2_min_luma_coding_block_size_minus3 + 3;
> +        unsigned int ctb_log2_size_y =
> +            min_cb_log2_size_y + sps->log2_diff_max_min_luma_coding_block_size;
> +        unsigned int ctb_size_y = 1 << ctb_log2_size_y;
> +        unsigned int pic_width_in_ctbs_y =
> +            (sps->pic_width_in_luma_samples + ctb_size_y - 1) / ctb_size_y;
> +        unsigned int pic_height_in_ctbs_y =
> +            (sps->pic_height_in_luma_samples + ctb_size_y - 1) / ctb_size_y;
> +
> +        ue(num_tile_columns_minus1, 0, FFMIN(pic_width_in_ctbs_y - 1, HEVC_MAX_TILE_COLUMNS - 1));
> +        ue(num_tile_rows_minus1,    0, FFMIN(pic_height_in_ctbs_y - 1, HEVC_MAX_TILE_ROWS - 1));
>           flag(uniform_spacing_flag);
>           if (!current->uniform_spacing_flag) {
>               for (i = 0; i < current->num_tile_columns_minus1; i++)

Gyan