Implement the missing requirements from H.266 (V3) p. 106 on the position and size of subpictures whose dimensions are provided explicitly.
Signed-off-by: Frank Plowman <[email protected]> --- Changes since v1 ([email protected]): * Use temporary variables and AV_CEIL_RSHIFT to make bound calculations more readable. * Fix bounds on size. The calculated values are minimums, not maximums as in v1. Additionally, fix an integer overflow in the bound calculations. libavcodec/cbs_h266_syntax_template.c | 49 +++++++++++++++++++++------ 1 file changed, 38 insertions(+), 11 deletions(-) diff --git a/libavcodec/cbs_h266_syntax_template.c b/libavcodec/cbs_h266_syntax_template.c index 9c37996947..a8f5af04d0 100644 --- a/libavcodec/cbs_h266_syntax_template.c +++ b/libavcodec/cbs_h266_syntax_template.c @@ -1061,7 +1061,7 @@ static int FUNC(sps)(CodedBitstreamContext *ctx, RWContext *rw, unsigned int ctb_log2_size_y, min_cb_log2_size_y, min_qt_log2_size_intra_y, min_qt_log2_size_inter_y, ctb_size_y, max_num_merge_cand, tmp_width_val, tmp_height_val; - uint8_t qp_bd_offset; + uint8_t qp_bd_offset, sub_width_c, sub_height_c; static const uint8_t h266_sub_width_c[] = { 1, 2, 2, 1 @@ -1089,6 +1089,9 @@ static int FUNC(sps)(CodedBitstreamContext *ctx, RWContext *rw, u(3, sps_max_sublayers_minus1, 0, VVC_MAX_SUBLAYERS - 1); u(2, sps_chroma_format_idc, 0, 3); + sub_width_c = h266_sub_width_c[current->sps_chroma_format_idc]; + sub_height_c = h266_sub_height_c[current->sps_chroma_format_idc]; + u(2, sps_log2_ctu_size_minus5, 0, 3); ctb_log2_size_y = current->sps_log2_ctu_size_minus5 + 5; ctb_size_y = 1 << ctb_log2_size_y; @@ -1110,8 +1113,6 @@ static int FUNC(sps)(CodedBitstreamContext *ctx, RWContext *rw, flag(sps_conformance_window_flag); if (current->sps_conformance_window_flag) { - uint8_t sub_width_c = h266_sub_width_c[current->sps_chroma_format_idc]; - uint8_t sub_height_c = h266_sub_height_c[current->sps_chroma_format_idc]; uint16_t width = current->sps_pic_width_max_in_luma_samples / sub_width_c; uint16_t height = current->sps_pic_height_max_in_luma_samples / sub_height_c; ue(sps_conf_win_left_offset, 0, width); @@ -1160,19 +1161,37 @@ 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) - ubs(wlen, sps_subpic_ctu_top_left_x[i], 1, i); - else + if (current->sps_pic_width_max_in_luma_samples > ctb_size_y) { + const unsigned 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, + AV_CEIL_RSHIFT(win_right_edge, ctb_log2_size_y) - 1, + 1, i); + } else infer(sps_subpic_ctu_top_left_x[i], 0); if (current->sps_pic_height_max_in_luma_samples > - ctb_size_y) - ubs(hlen, sps_subpic_ctu_top_left_y[i], 1, i); - else + ctb_size_y) { + const unsigned 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, + AV_CEIL_RSHIFT(win_bottom_edge, ctb_log2_size_y) - 1, + 1, i); + } else infer(sps_subpic_ctu_top_left_y[i], 0); if (i < current->sps_num_subpics_minus1 && current->sps_pic_width_max_in_luma_samples > ctb_size_y) { - ubs(wlen, sps_subpic_width_minus1[i], 1, i); + const unsigned int win_left_edge = + current->sps_conf_win_left_offset * sub_width_c; + const unsigned 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] + ? win_left_edge_ctus - current->sps_subpic_ctu_top_left_x[i] + : 0, + MAX_UINT_BITS(wlen), 1, i); } else { infer(sps_subpic_width_minus1[i], tmp_width_val - @@ -1181,7 +1200,15 @@ 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) { - ubs(hlen, sps_subpic_height_minus1[i], 1, i); + const unsigned int win_top_edge = + current->sps_conf_win_top_offset * sub_height_c; + const unsigned 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] + ? win_top_edge_ctus - current->sps_subpic_ctu_top_left_y[i] + : 0, + MAX_UINT_BITS(wlen), 1, i); } else { infer(sps_subpic_height_minus1[i], tmp_height_val - -- 2.46.0 _______________________________________________ ffmpeg-devel mailing list [email protected] https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
