[FFmpeg-devel] [PATCH 1/6] lavc/vvc: Use second definition of MinQtLog2SizeIntraC if relevant

[Frank Plowman]

MinQtLog2SizeIntraC is usually (eq. (51) from VVCv3) defined as

sps_log2_diff_min_qt_min_cb_intra_slice_chroma + MinCbLog2SizeY

However, in the case ph_log2_diff_min_qt_min_cb_intra_slice_chroma is
present, it is instead (eq. (83) from VVCv3) defined as

ph_log2_diff_min_qt_min_cb_intra_slice_chroma + MinCbLog2SizeY

When ph_log2_diff_max_bt_min_qt_intra_slice_chroma and
ph_log2_diff_max_tt_min_qt_intra_slice_chroma are present, so is
ph_log2_diff_min_qt_min_cb_intra_slice_chroma, and so we should use the
second definition of MinQtLog2SizeIntraC, rather than the first, when
calculating the bounds for these syntax elements.

Signed-off-by: Frank Plowman <post at frankplowman.com>
---
 libavcodec/cbs_h266_syntax_template.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/cbs_h266_syntax_template.c b/libavcodec/cbs_h266_syntax_template.c
index 6b2d6534ef..83d945ec74 100644
--- a/libavcodec/cbs_h266_syntax_template.c
+++ b/libavcodec/cbs_h266_syntax_template.c
@@ -2811,7 +2811,7 @@ static int FUNC(picture_header) (CodedBitstreamContext *ctx, RWContext *rw,
                    0, 2 * (ctb_log2_size_y - min_cb_log2_size_y));
                 if (sps->sps_max_mtt_hierarchy_depth_intra_slice_chroma != 0) {
                     unsigned int min_qt_log2_size_intra_c =
-                        sps->sps_log2_diff_min_qt_min_cb_intra_slice_chroma +
+                        current->ph_log2_diff_min_qt_min_cb_intra_slice_chroma +
                         min_cb_log2_size_y;
                     ue(ph_log2_diff_max_bt_min_qt_intra_slice_chroma,
                        0, FFMIN(6, ctb_log2_size_y) - min_qt_log2_size_intra_c);
-- 
2.47.0