[isp] Fix luma cbf writing for ISP splits. Do not write luma cbf if first three splits had luma cbf 0.

This commit is contained in:
siivonek 2022-09-13 13:27:16 +03:00 committed by Marko Viitanen
parent a28e61eff7
commit 7ba557af6b

View file

@ -622,6 +622,7 @@ static void encode_transform_coeff(
lcu_coeff_t* coeff,
enum uvg_tree_type tree_type,
bool last_split,
bool can_skip_last_cbf,
int *luma_cbf_ctx, // Always true except when writing sub partition coeffs (ISP)
cu_loc_t *original_loc) // Original dimensions before ISP split
{
@ -631,6 +632,8 @@ static void encode_transform_coeff(
const int width = cu_loc->width;
const int height = cu_loc->height;
bool isp_split = cu_loc->x != original_loc->x || cu_loc->y != original_loc->y;
//const encoder_control_t *const ctrl = state->encoder_control;
const videoframe_t * const frame = state->tile->frame;
const cu_array_t* used_array = tree_type != UVG_CHROMA_T ? frame->cu_array : frame->chroma_cu_array;
@ -710,7 +713,7 @@ static void encode_transform_coeff(
cu_loc_t loc;
uvg_cu_loc_ctor(&loc, (x + i * split_width), (y + j * split_height), width >> 1, height >> 1);
encode_transform_coeff(state, &loc, depth + 1, tr_depth + 1, cb_flag_u, cb_flag_v, only_chroma, coeff, tree_type, true, luma_cbf_ctx, &loc);
encode_transform_coeff(state, &loc, depth + 1, tr_depth + 1, cb_flag_u, cb_flag_v, only_chroma, coeff, tree_type, true, false, luma_cbf_ctx, &loc);
}
}
return;
@ -722,11 +725,15 @@ static void encode_transform_coeff(
// - we have chroma coefficients at this level
// When it is not present, it is inferred to be 1.
if ((cur_cu->type == CU_INTRA || tr_depth > 0 || cb_flag_u || cb_flag_v) && !only_chroma && tree_type != UVG_CHROMA_T) {
if (can_skip_last_cbf && isp_split && last_split) {
// Do not write luma cbf if first three isp splits have luma cbf 0
} else {
cabac->cur_ctx = &(cabac->ctx.qt_cbf_model_luma[*luma_cbf_ctx]);
CABAC_BIN(cabac, cb_flag_y, "cbf_luma");
if (tr_depth == 0) {
*luma_cbf_ctx = 2 + cb_flag_y;
}
}
}
if (cb_flag_y | cb_flag_u | cb_flag_v) {
@ -1621,7 +1628,7 @@ void uvg_encode_coding_tree(
// Code (possible) coeffs to bitstream
if (cbf) {
int luma_cbf_ctx = 0;
encode_transform_coeff(state, &cu_loc, depth, 0, 0, 0, 0, coeff, tree_type, true, &luma_cbf_ctx, &cu_loc);
encode_transform_coeff(state, &cu_loc, depth, 0, 0, 0, 0, coeff, tree_type, true, false, &luma_cbf_ctx, &cu_loc);
}
encode_mts_idx(state, cabac, cur_cu);
@ -1645,13 +1652,16 @@ void uvg_encode_coding_tree(
int split_type = cur_cu->intra.isp_mode;
int split_limit = split_type == ISP_MODE_NO_ISP ? 1 : uvg_get_isp_split_num(cu_width, cu_height, split_type);
luma_cbf_ctx = split_limit != 1 ? 2 : 0;
// If all first three splits have luma cbf 0, the last one must be one. Since the value ca be derived, no need to write it
bool can_skip_last_cbf = true;
for (int i = 0; i < split_limit; ++i) {
cu_loc_t split_loc;
uvg_get_isp_split_loc(&split_loc, x, y, cu_width, cu_height, i, split_type);
// Check if last split to write chroma
bool last_split = (i + 1) == split_limit;
encode_transform_coeff(state, &split_loc, depth, 0, 0, 0, 0, coeff, tree_type, last_split, &luma_cbf_ctx, &cu_loc);
encode_transform_coeff(state, &split_loc, depth, 0, 0, 0, 0, coeff, tree_type, last_split, can_skip_last_cbf, &luma_cbf_ctx, &cu_loc);
can_skip_last_cbf &= luma_cbf_ctx == 2;
}
}
@ -1670,7 +1680,7 @@ void uvg_encode_coding_tree(
tmp->violates_lfnst_constrained_luma = false;
tmp->violates_lfnst_constrained_chroma = false;
tmp->lfnst_last_scan_pos = false;
encode_transform_coeff(state, &cu_loc, depth, 0, 0, 0, 1, coeff, tree_type, true, &luma_cbf_ctx, &cu_loc);
encode_transform_coeff(state, &cu_loc, depth, 0, 0, 0, 1, coeff, tree_type, true, false, &luma_cbf_ctx, &cu_loc);
// Write LFNST only once for single tree structure
encode_lfnst_idx(state, cabac, tmp, x, y, depth, cu_width, cu_height, tree_type, COLOR_UV);
}