/*

 * VVC parameter set parser

 *

 * Copyright (C) 2023 Nuo Mi

 * Copyright (C) 2022 Xu Mu

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * FFmpeg is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with FFmpeg; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#include <stdbool.h>

#include "libavcodec/cbs_h266.h"

#include "libavcodec/decode.h"

#include "libavcodec/h2645data.h"

#include "libavutil/mem.h"

#include "libavutil/pixdesc.h"

#include "libavutil/refstruct.h"

#include "data.h"

#include "ps.h"

#include "dec.h"

static int sps_map_pixel_format(VVCSPS *sps, void *log_ctx)

{

    const H266RawSPS *r = sps->r;

    const AVPixFmtDescriptor *desc;

    switch (sps->bit_depth) {

    case 8:

        if (r->sps_chroma_format_idc == 0) sps->pix_fmt = AV_PIX_FMT_GRAY8;

        if (r->sps_chroma_format_idc == 1) sps->pix_fmt = AV_PIX_FMT_YUV420P;

        if (r->sps_chroma_format_idc == 2) sps->pix_fmt = AV_PIX_FMT_YUV422P;

        if (r->sps_chroma_format_idc == 3) sps->pix_fmt = AV_PIX_FMT_YUV444P;

       break;

    case 10:

        if (r->sps_chroma_format_idc == 0) sps->pix_fmt = AV_PIX_FMT_GRAY10;

        if (r->sps_chroma_format_idc == 1) sps->pix_fmt = AV_PIX_FMT_YUV420P10;

        if (r->sps_chroma_format_idc == 2) sps->pix_fmt = AV_PIX_FMT_YUV422P10;

        if (r->sps_chroma_format_idc == 3) sps->pix_fmt = AV_PIX_FMT_YUV444P10;

        break;

    case 12:

        if (r->sps_chroma_format_idc == 0) sps->pix_fmt = AV_PIX_FMT_GRAY12;

        if (r->sps_chroma_format_idc == 1) sps->pix_fmt = AV_PIX_FMT_YUV420P12;

        if (r->sps_chroma_format_idc == 2) sps->pix_fmt = AV_PIX_FMT_YUV422P12;

        if (r->sps_chroma_format_idc == 3) sps->pix_fmt = AV_PIX_FMT_YUV444P12;

        break;

    default:

        av_log(log_ctx, AV_LOG_ERROR,

               "The following bit-depths are currently specified: 8, 10, 12 bits, "

               "chroma_format_idc is %d, depth is %d\n",

               r->sps_chroma_format_idc, sps->bit_depth);

        return AVERROR_INVALIDDATA;

    }

    desc = av_pix_fmt_desc_get(sps->pix_fmt);

    if (!desc)

        return AVERROR(EINVAL);

    sps->hshift[0] = sps->vshift[0] = 0;

    sps->hshift[2] = sps->hshift[1] = desc->log2_chroma_w;

    sps->vshift[2] = sps->vshift[1] = desc->log2_chroma_h;

    sps->pixel_shift = sps->bit_depth > 8;

    return 0;

}

static int sps_bit_depth(VVCSPS *sps, void *log_ctx)

{

    const H266RawSPS *r = sps->r;

    sps->bit_depth = r->sps_bitdepth_minus8 + 8;

    sps->qp_bd_offset = 6 * (sps->bit_depth - 8);

    sps->log2_transform_range =

        r->sps_extended_precision_flag ? FFMAX(15, FFMIN(20, sps->bit_depth + 6)) : 15;

    return sps_map_pixel_format(sps, log_ctx);

}

static int sps_chroma_qp_table(VVCSPS *sps)

{

    const H266RawSPS *r = sps->r;

    const int num_qp_tables = r->sps_same_qp_table_for_chroma_flag ?

        1 : (r->sps_joint_cbcr_enabled_flag ? 3 : 2);

    for (int i = 0; i < num_qp_tables; i++) {

        int num_points_in_qp_table;

        int8_t qp_in[VVC_MAX_POINTS_IN_QP_TABLE], qp_out[VVC_MAX_POINTS_IN_QP_TABLE];

        unsigned int delta_qp_in[VVC_MAX_POINTS_IN_QP_TABLE];

        int off = sps->qp_bd_offset;

        num_points_in_qp_table = r->sps_num_points_in_qp_table_minus1[i] + 1;

        qp_out[0] = qp_in[0] = r->sps_qp_table_start_minus26[i] + 26;

        for (int j = 0; j < num_points_in_qp_table; j++ ) {

            const uint8_t delta_qp_out = (r->sps_delta_qp_in_val_minus1[i][j] ^ r->sps_delta_qp_diff_val[i][j]);

            delta_qp_in[j] = r->sps_delta_qp_in_val_minus1[i][j] + 1;

            // Note: we cannot check qp_{in,out}[j+1] here as qp_*[j] + delta_qp_*

            //       may not fit in an 8-bit signed integer.

            if (qp_in[j] + delta_qp_in[j] > 63 || qp_out[j] + delta_qp_out > 63)

                return AVERROR(EINVAL);

            qp_in[j+1] = qp_in[j] + delta_qp_in[j];

            qp_out[j+1] = qp_out[j] + delta_qp_out;

        }

        sps->chroma_qp_table[i][qp_in[0] + off] = qp_out[0];

        for (int k = qp_in[0] - 1 + off; k >= 0; k--)

            sps->chroma_qp_table[i][k] = av_clip(sps->chroma_qp_table[i][k+1]-1, -off, 63);

        for (int j  = 0; j < num_points_in_qp_table; j++) {

            int sh = delta_qp_in[j] >> 1;

            for (int k = qp_in[j] + 1 + off, m = 1; k <= qp_in[j+1] + off; k++, m++) {

                sps->chroma_qp_table[i][k] = sps->chroma_qp_table[i][qp_in[j] + off] +

                    ((qp_out[j+1] - qp_out[j]) * m + sh) / delta_qp_in[j];

            }

        }

        for (int k = qp_in[num_points_in_qp_table] + 1 + off; k <= 63 + off; k++)

            sps->chroma_qp_table[i][k]  = av_clip(sps->chroma_qp_table[i][k-1] + 1, -sps->qp_bd_offset, 63);

    }

    if (r->sps_same_qp_table_for_chroma_flag) {

        memcpy(&sps->chroma_qp_table[1], &sps->chroma_qp_table[0], sizeof(sps->chroma_qp_table[0]));

        memcpy(&sps->chroma_qp_table[2], &sps->chroma_qp_table[0], sizeof(sps->chroma_qp_table[0]));

    }

    return 0;

}

static void sps_poc(VVCSPS *sps)

{

    sps->max_pic_order_cnt_lsb = 1 << (sps->r->sps_log2_max_pic_order_cnt_lsb_minus4 + 4);

}

static void sps_inter(VVCSPS *sps)

{

    const H266RawSPS *r = sps->r;

    sps->max_num_merge_cand     = 6 - r->sps_six_minus_max_num_merge_cand;

    sps->max_num_ibc_merge_cand = 6 - r->sps_six_minus_max_num_ibc_merge_cand;

    if (sps->r->sps_gpm_enabled_flag) {

        sps->max_num_gpm_merge_cand = 2;

        if (sps->max_num_merge_cand >= 3)

            sps->max_num_gpm_merge_cand = sps->max_num_merge_cand - r->sps_max_num_merge_cand_minus_max_num_gpm_cand;

    }

    sps->log2_parallel_merge_level = r->sps_log2_parallel_merge_level_minus2 + 2;

}

static void sps_partition_constraints(VVCSPS* sps)

{

    const H266RawSPS *r = sps->r;

    sps->ctb_log2_size_y    = r->sps_log2_ctu_size_minus5 + 5;

    sps->ctb_size_y         = 1 << sps->ctb_log2_size_y;

    sps->min_cb_log2_size_y = r->sps_log2_min_luma_coding_block_size_minus2 + 2;

    sps->min_cb_size_y      = 1 << sps->min_cb_log2_size_y;

    sps->max_tb_size_y      = 1 << (r->sps_max_luma_transform_size_64_flag ? 6 : 5);

    sps->max_ts_size        = 1 << (r->sps_log2_transform_skip_max_size_minus2 + 2);

}

static void sps_ladf(VVCSPS* sps)

{

    const H266RawSPS *r = sps->r;

    if (r->sps_ladf_enabled_flag) {

        sps->num_ladf_intervals = r->sps_num_ladf_intervals_minus2 + 2;

        sps->ladf_interval_lower_bound[0] = 0;

        for (int i = 0; i < sps->num_ladf_intervals - 1; i++) {

            sps->ladf_interval_lower_bound[i + 1] =

                sps->ladf_interval_lower_bound[i] + r->sps_ladf_delta_threshold_minus1[i] + 1;

        }

    }

}

#define EXTENDED_SAR       255

static void sps_vui(AVCodecContext *c, const H266RawVUI *vui)

{

    AVRational sar = (AVRational){ 0, 1 };

    if (vui->vui_aspect_ratio_info_present_flag) {

        if (vui->vui_aspect_ratio_idc < FF_ARRAY_ELEMS(ff_h2645_pixel_aspect))

            sar = ff_h2645_pixel_aspect[vui->vui_aspect_ratio_idc];

        else if (vui->vui_aspect_ratio_idc == EXTENDED_SAR) {

            sar = (AVRational){ vui->vui_sar_width, vui->vui_sar_height };

        } else {

            av_log(c, AV_LOG_WARNING, "Unknown SAR index: %u.\n", vui->vui_aspect_ratio_idc);

        }

    }

    ff_set_sar(c, sar);

    if (vui->vui_colour_description_present_flag) {

        c->color_primaries = vui->vui_colour_primaries;

        c->color_trc       = vui->vui_transfer_characteristics;

        c->colorspace      = vui->vui_matrix_coeffs;

        c->color_range     = vui->vui_full_range_flag ? AVCOL_RANGE_JPEG : AVCOL_RANGE_MPEG;

        // Set invalid values to "unspecified"

        if (!av_color_primaries_name(c->color_primaries))

            c->color_primaries = AVCOL_PRI_UNSPECIFIED;

        if (!av_color_transfer_name(c->color_trc))

            c->color_trc = AVCOL_TRC_UNSPECIFIED;

        if (!av_color_space_name(c->colorspace))

            c->colorspace = AVCOL_SPC_UNSPECIFIED;

    } else {

        c->color_primaries = AVCOL_PRI_UNSPECIFIED;

        c->color_trc       = AVCOL_TRC_UNSPECIFIED;

        c->colorspace      = AVCOL_SPC_UNSPECIFIED;

        c->color_range     = AVCOL_RANGE_MPEG;

    }

}

static void sps_export_stream_params(AVCodecContext *c, const VVCSPS *sps)

{

    const H266RawSPS *r = sps->r;

    c->has_b_frames = !!r->sps_dpb_params.dpb_max_num_reorder_pics[r->sps_max_sublayers_minus1];

    if (r->sps_vui_parameters_present_flag)

        sps_vui(c, &r->vui);

}

static int sps_derive(VVCSPS *sps, AVCodecContext *c)

{

    int ret;

    const H266RawSPS *r = sps->r;

    ret = sps_bit_depth(sps, c);

    if (ret < 0)

        return ret;

    sps_poc(sps);

    sps_inter(sps);

    sps_partition_constraints(sps);

    sps_ladf(sps);

    if (r->sps_chroma_format_idc != 0) {

        ret = sps_chroma_qp_table(sps);

        if (ret < 0)

            return ret;

    }

    sps_export_stream_params(c, sps);

    return 0;

}

static void sps_free(AVRefStructOpaque opaque, void *obj)

{

    VVCSPS *sps = obj;

    av_refstruct_unref(&sps->r);

}

static const VVCSPS *sps_alloc(const H266RawSPS *rsps, AVCodecContext *c)

{

    int ret;

    VVCSPS *sps = av_refstruct_alloc_ext(sizeof(*sps), 0, NULL, sps_free);

    if (!sps)

        return NULL;

    av_refstruct_replace(&sps->r, rsps);

    ret = sps_derive(sps, c);

    if (ret < 0)

        goto fail;

    return sps;

fail:

    av_refstruct_unref(&sps);

    return NULL;

}

static int decode_sps(VVCParamSets *ps, AVCodecContext *c, const H266RawSPS *rsps, int is_clvss)

{

    VVCContext *s           = c->priv_data;

    const int sps_id        = rsps->sps_seq_parameter_set_id;

    const VVCSPS *old_sps   = ps->sps_list[sps_id];

    const VVCSPS *sps;

    if (is_clvss) {

        ps->sps_id_used = 0;

        s->seq_decode = (s->seq_decode + 1) & 0xff;

    }

    if (old_sps) {

        if (old_sps->r == rsps || !memcmp(old_sps->r, rsps, sizeof(*old_sps->r))) {

            ps->sps_id_used |= (1 << sps_id);

            return 0;

        } else if (ps->sps_id_used & (1 << sps_id))

            return AVERROR_INVALIDDATA;

    }

    sps = sps_alloc(rsps, c);

    if (!sps)

        return AVERROR(ENOMEM);

    av_refstruct_unref(&ps->sps_list[sps_id]);

    ps->sps_list[sps_id] = sps;

    ps->sps_id_used |= (1 << sps_id);

    return 0;

}

static void pps_chroma_qp_offset(VVCPPS *pps)

{

    pps->chroma_qp_offset[CB - 1]   = pps->r->pps_cb_qp_offset;

    pps->chroma_qp_offset[CR - 1]   = pps->r->pps_cr_qp_offset;

    pps->chroma_qp_offset[JCBCR - 1]= pps->r->pps_joint_cbcr_qp_offset_value;

    for (int i = 0; i < 6; i++) {

        pps->chroma_qp_offset_list[i][CB - 1]   = pps->r->pps_cb_qp_offset_list[i];

        pps->chroma_qp_offset_list[i][CR - 1]   = pps->r->pps_cr_qp_offset_list[i];

        pps->chroma_qp_offset_list[i][JCBCR - 1]= pps->r->pps_joint_cbcr_qp_offset_list[i];

    }

}

static void pps_width_height(VVCPPS *pps, const VVCSPS *sps)

{

    const H266RawPPS *r = pps->r;

    pps->width          = r->pps_pic_width_in_luma_samples;

    pps->height         = r->pps_pic_height_in_luma_samples;

    pps->ctb_width      = AV_CEIL_RSHIFT(pps->width,  sps->ctb_log2_size_y);

    pps->ctb_height     = AV_CEIL_RSHIFT(pps->height, sps->ctb_log2_size_y);

    pps->ctb_count      = pps->ctb_width * pps->ctb_height;

    pps->min_cb_width   = pps->width  >> sps->min_cb_log2_size_y;

    pps->min_cb_height  = pps->height >> sps->min_cb_log2_size_y;

    pps->min_pu_width   = pps->width  >> MIN_PU_LOG2;

    pps->min_pu_height  = pps->height >> MIN_PU_LOG2;

    pps->min_tu_width   = pps->width  >> MIN_TU_LOG2;

    pps->min_tu_height  = pps->height >> MIN_TU_LOG2;

    pps->width32        = AV_CEIL_RSHIFT(pps->width,  5);

    pps->height32       = AV_CEIL_RSHIFT(pps->height, 5);

    pps->width64        = AV_CEIL_RSHIFT(pps->width,  6);

    pps->height64       = AV_CEIL_RSHIFT(pps->height, 6);

}

static int pps_bd(VVCPPS *pps)

{

    const H266RawPPS *r = pps->r;

    pps->col_bd        = av_calloc(r->num_tile_columns  + 1, sizeof(*pps->col_bd));

    pps->row_bd        = av_calloc(r->num_tile_rows  + 1,    sizeof(*pps->row_bd));

    pps->ctb_to_col_bd = av_calloc(pps->ctb_width  + 1,      sizeof(*pps->ctb_to_col_bd));

    pps->ctb_to_row_bd = av_calloc(pps->ctb_height + 1,      sizeof(*pps->ctb_to_col_bd));

    if (!pps->col_bd || !pps->row_bd || !pps->ctb_to_col_bd || !pps->ctb_to_row_bd)

        return AVERROR(ENOMEM);

    for (int i = 0, j = 0; i < r->num_tile_columns; i++) {

        pps->col_bd[i] = j;

        j += r->col_width_val[i];

        for (int k = pps->col_bd[i]; k < j; k++)

            pps->ctb_to_col_bd[k] = pps->col_bd[i];

    }

    pps->col_bd[r->num_tile_columns] = pps->ctb_to_col_bd[pps->ctb_width] = pps->ctb_width;

    for (int i = 0, j = 0; i < r->num_tile_rows; i++) {

        pps->row_bd[i] = j;

        j += r->row_height_val[i];

        for (int k = pps->row_bd[i]; k < j; k++)

            pps->ctb_to_row_bd[k] = pps->row_bd[i];

    }

    pps->row_bd[r->num_tile_rows] = pps->ctb_to_row_bd[pps->ctb_height] = pps->ctb_height;

    return 0;

}

static int next_tile_idx(int tile_idx, const int i, const H266RawPPS *r)

{

    if (r->pps_tile_idx_delta_present_flag) {

        tile_idx += r->pps_tile_idx_delta_val[i];

    } else {

        tile_idx += r->pps_slice_width_in_tiles_minus1[i] + 1;

        if (tile_idx % r->num_tile_columns == 0)

            tile_idx += (r->pps_slice_height_in_tiles_minus1[i]) * r->num_tile_columns;

    }

    return tile_idx;

}

static void tile_xy(int *tile_x, int *tile_y, const int tile_idx, const VVCPPS *pps)

{

    *tile_x = tile_idx % pps->r->num_tile_columns;

    *tile_y = tile_idx / pps->r->num_tile_columns;

}

static void ctu_xy(int *rx, int *ry, const int tile_x, const int tile_y, const VVCPPS *pps)

{

    *rx = pps->col_bd[tile_x];

    *ry = pps->row_bd[tile_y];

}

static int ctu_rs(const int rx, const int ry, const VVCPPS *pps)

{

    return pps->ctb_width * ry + rx;

}

static int pps_add_ctus(VVCPPS *pps, int *off, const int rx, const int ry,

    const int w, const int h)

{

    int start = *off;

    for (int y = 0; y < h; y++) {

        for (int x = 0; x < w; x++) {

            if (*off >= pps->ctb_count)

                return AVERROR_INVALIDDATA;

            pps->ctb_addr_in_slice[*off] = ctu_rs(rx + x, ry + y, pps);

            (*off)++;

        }

    }

    return *off - start;

}

static int pps_single_slice_picture(VVCPPS *pps, int *off)

{

    pps->num_ctus_in_slice[0] = 0;

    for (int j = 0; j < pps->r->num_tile_rows; j++) {

        for (int i = 0; i < pps->r->num_tile_columns; i++) {

            const int ret = pps_add_ctus(pps, off,

                pps->col_bd[i], pps->row_bd[j],

                pps->r->col_width_val[i], pps->r->row_height_val[j]);

            if (ret < 0)

                return ret;

            pps->num_ctus_in_slice[0] += ret;

        }

    }

    return 0;

}

static void subpic_tiles(int *tile_x, int *tile_y, int *tile_x_end, int *tile_y_end,

    const VVCSPS *sps, const VVCPPS *pps,  const int i)

{

    const int rx = sps->r->sps_subpic_ctu_top_left_x[i];

    const int ry = sps->r->sps_subpic_ctu_top_left_y[i];

    *tile_x = *tile_y = 0;

    while (pps->col_bd[*tile_x] < rx)

        (*tile_x)++;

    while (pps->row_bd[*tile_y] < ry)

        (*tile_y)++;

    *tile_x_end = (*tile_x);

    *tile_y_end = (*tile_y);

    while (pps->col_bd[*tile_x_end] < rx + sps->r->sps_subpic_width_minus1[i] + 1)

        (*tile_x_end)++;

    while (pps->row_bd[*tile_y_end] < ry + sps->r->sps_subpic_height_minus1[i] + 1)

        (*tile_y_end)++;

}

static int pps_subpic_less_than_one_tile_slice(VVCPPS *pps, const VVCSPS *sps, const int i, const int tx, const int ty, int *off)

{

    const int ret = pps_add_ctus(pps, off,

        sps->r->sps_subpic_ctu_top_left_x[i], sps->r->sps_subpic_ctu_top_left_y[i],

        sps->r->sps_subpic_width_minus1[i] + 1, sps->r->sps_subpic_height_minus1[i] + 1);

    if (ret < 0)

        return ret;

    pps->num_ctus_in_slice[i] = ret;

    return 0;

}

static int pps_subpic_one_or_more_tiles_slice(VVCPPS *pps, const int tile_x, const int tile_y, const int x_end, const int y_end,

    const int i, int *off)

{

    for (int ty = tile_y; ty < y_end; ty++) {

        for (int tx = tile_x; tx < x_end; tx++) {

            const int ret = pps_add_ctus(pps, off,

                pps->col_bd[tx], pps->row_bd[ty],

                pps->r->col_width_val[tx], pps->r->row_height_val[ty]);

            if (ret < 0)

                return ret;

            pps->num_ctus_in_slice[i] += ret;

        }

    }

    return 0;

}

static int pps_subpic_slice(VVCPPS *pps, const VVCSPS *sps, const int i, int *off)

{

    int tx, ty, x_end, y_end;

    pps->slice_start_offset[i] = *off;

    pps->num_ctus_in_slice[i] = 0;

    subpic_tiles(&tx, &ty, &x_end, &y_end, sps, pps, i);

    if (ty + 1 == y_end && sps->r->sps_subpic_height_minus1[i] + 1 < pps->r->row_height_val[ty])

        return pps_subpic_less_than_one_tile_slice(pps, sps, i, tx, ty, off);

    else

        return pps_subpic_one_or_more_tiles_slice(pps, tx, ty, x_end, y_end, i, off);

}

static int pps_single_slice_per_subpic(VVCPPS *pps, const VVCSPS *sps, int *off)

{

    int ret;

    if (!sps->r->sps_subpic_info_present_flag) {

        ret = pps_single_slice_picture(pps, off);

        if (ret < 0)

            return ret;

    } else {

        for (int i = 0; i < pps->r->pps_num_slices_in_pic_minus1 + 1; i++) {

            const int ret = pps_subpic_slice(pps, sps, i, off);

            if (ret < 0)

                return ret;

        }

    }

    return 0;

}

static int pps_one_tile_slices(VVCPPS *pps, const int tile_idx, int i, int *off)

{

    const H266RawPPS *r = pps->r;

    int rx, ry, ctu_y_end, tile_x, tile_y;

    tile_xy(&tile_x, &tile_y, tile_idx, pps);

    ctu_xy(&rx, &ry, tile_x, tile_y, pps);

    ctu_y_end = ry + r->row_height_val[tile_y];

    while (ry < ctu_y_end) {

        int ret;

        pps->slice_start_offset[i] = *off;

        ret = pps_add_ctus(pps, off, rx, ry,

            r->col_width_val[tile_x], r->slice_height_in_ctus[i]);

        if (ret < 0)

            return ret;

        pps->num_ctus_in_slice[i] = ret;

        ry += r->slice_height_in_ctus[i++];

    }

    i--;

    return i;

}

static int pps_multi_tiles_slice(VVCPPS *pps, const int tile_idx, const int i, int *off, bool *tile_in_slice)

{

    const H266RawPPS *r = pps->r;

    int rx, ry, tile_x, tile_y;

    tile_xy(&tile_x, &tile_y, tile_idx, pps);

    pps->slice_start_offset[i] = *off;

    pps->num_ctus_in_slice[i] = 0;

    for (int ty = tile_y; ty <= tile_y + r->pps_slice_height_in_tiles_minus1[i]; ty++) {

        for (int tx = tile_x; tx <= tile_x + r->pps_slice_width_in_tiles_minus1[i]; tx++) {

            int ret;

            const int idx = ty * r->num_tile_columns + tx;

            if (tile_in_slice[idx])

                return AVERROR_INVALIDDATA;

            tile_in_slice[idx] = true;

            ctu_xy(&rx, &ry, tx, ty, pps);

            ret = pps_add_ctus(pps, off, rx, ry,

                r->col_width_val[tx], r->row_height_val[ty]);

            if (ret < 0)

                return ret;

            pps->num_ctus_in_slice[i] += ret;

        }

    }

    return 0;

}

static int pps_rect_slice(VVCPPS *pps, const VVCSPS *sps)

{

    const H266RawPPS *r = pps->r;

    bool tile_in_slice[VVC_MAX_TILES_PER_AU] = {false};

    int tile_idx = 0, off = 0, ret;

    if (r->pps_single_slice_per_subpic_flag) {

        return pps_single_slice_per_subpic(pps, sps, &off);

    }

    for (int i = 0; i < r->pps_num_slices_in_pic_minus1 + 1; i++) {

        if (!r->pps_slice_width_in_tiles_minus1[i] &&

            !r->pps_slice_height_in_tiles_minus1[i]) {

            if (tile_in_slice[tile_idx])

                return AVERROR_INVALIDDATA;

            tile_in_slice[tile_idx] = true;

            ret = pps_one_tile_slices(pps, tile_idx, i, &off);

            if (ret < 0)

                return ret;

            i = ret;

        } else {

            ret = pps_multi_tiles_slice(pps, tile_idx, i, &off, tile_in_slice);

            if (ret < 0)

                return ret;

        }

        tile_idx = next_tile_idx(tile_idx, i, r);

    }

    for (int i = 0; i < r->num_tiles_in_pic; i++) {

        if (!tile_in_slice[i])

            return AVERROR_INVALIDDATA;

    }

    return 0;

}

static int pps_no_rect_slice(VVCPPS* pps)

{

    const H266RawPPS* r = pps->r;

    int rx, ry, off = 0;

    for (int tile_y = 0; tile_y < r->num_tile_rows; tile_y++) {

        for (int tile_x = 0; tile_x < r->num_tile_columns; tile_x++) {

            int ret;

            ctu_xy(&rx, &ry, tile_x, tile_y, pps);

            ret = pps_add_ctus(pps, &off, rx, ry, r->col_width_val[tile_x], r->row_height_val[tile_y]);

            if (ret < 0)

                return ret;

        }

    }

    return 0;

}

static int pps_slice_map(VVCPPS *pps, const VVCSPS *sps)

{

    int ret;

    pps->ctb_addr_in_slice = av_calloc(pps->ctb_count, sizeof(*pps->ctb_addr_in_slice));

    if (!pps->ctb_addr_in_slice)

        return AVERROR(ENOMEM);

    if (pps->r->pps_rect_slice_flag)

        return pps_rect_slice(pps, sps);

    ret = pps_no_rect_slice(pps);

    if (ret < 0)

        return ret;

    return 0;

}

static void pps_ref_wraparound_offset(VVCPPS *pps, const VVCSPS *sps)

{

    const H266RawPPS *r = pps->r;

    if (r->pps_ref_wraparound_enabled_flag)

        pps->ref_wraparound_offset = (pps->width / sps->min_cb_size_y) - r->pps_pic_width_minus_wraparound_offset;

}

static void pps_subpic(VVCPPS *pps, const VVCSPS *sps)

{

    const H266RawSPS *rsps = sps->r;

    for (int i = 0; i < rsps->sps_num_subpics_minus1 + 1; i++) {

        if (rsps->sps_subpic_treated_as_pic_flag[i]) {

            pps->subpic_x[i]      = rsps->sps_subpic_ctu_top_left_x[i] << sps->ctb_log2_size_y;

            pps->subpic_y[i]      = rsps->sps_subpic_ctu_top_left_y[i] << sps->ctb_log2_size_y;

            pps->subpic_width[i]  = FFMIN(pps->width  - pps->subpic_x[i], (rsps->sps_subpic_width_minus1[i]  + 1) << sps->ctb_log2_size_y);

            pps->subpic_height[i] = FFMIN(pps->height - pps->subpic_y[i], (rsps->sps_subpic_height_minus1[i] + 1) << sps->ctb_log2_size_y);

        } else {

            pps->subpic_x[i]      = 0;

            pps->subpic_y[i]      = 0;

            pps->subpic_width[i]  = pps->width;

            pps->subpic_height[i] = pps->height;

        }

    }

}

static int pps_derive(VVCPPS *pps, const VVCSPS *sps)

{

    int ret;

    pps_chroma_qp_offset(pps);

    pps_width_height(pps, sps);

    ret = pps_bd(pps);

    if (ret < 0)

        return ret;

    ret = pps_slice_map(pps, sps);

    if (ret < 0)

        return ret;

    pps_ref_wraparound_offset(pps, sps);

    pps_subpic(pps, sps);

    return 0;

}

static void pps_free(AVRefStructOpaque opaque, void *obj)

{

    VVCPPS *pps = obj;

    av_refstruct_unref(&pps->r);

    av_freep(&pps->col_bd);

    av_freep(&pps->row_bd);

    av_freep(&pps->ctb_to_col_bd);

    av_freep(&pps->ctb_to_row_bd);

    av_freep(&pps->ctb_addr_in_slice);

}

static const VVCPPS *pps_alloc(const H266RawPPS *rpps, const VVCSPS *sps)

{

    int ret;

    VVCPPS *pps = av_refstruct_alloc_ext(sizeof(*pps), 0, NULL, pps_free);

    if (!pps)

        return NULL;

    av_refstruct_replace(&pps->r, rpps);

    ret = pps_derive(pps, sps);

    if (ret < 0)

        goto fail;

    return pps;

fail:

    av_refstruct_unref(&pps);

    return NULL;

}

static int decode_pps(VVCParamSets *ps, const H266RawPPS *rpps)

{

    int ret                 = 0;

    const int pps_id        = rpps->pps_pic_parameter_set_id;

    const int sps_id        = rpps->pps_seq_parameter_set_id;

    const VVCPPS *old_pps   = ps->pps_list[pps_id];

    const VVCPPS *pps;

    if (old_pps && old_pps->r == rpps)

        return 0;

    pps = pps_alloc(rpps, ps->sps_list[sps_id]);

    if (!pps)

        return AVERROR(ENOMEM);

    av_refstruct_unref(&ps->pps_list[pps_id]);

    ps->pps_list[pps_id] = pps;

    return ret;

}

static int decode_ps(VVCParamSets *ps, AVCodecContext *c, const SliceContext *sc, int is_clvss)

{

    const H266RawSlice *sl = sc->ref;

    const H266RawPPS *rpps = sl->pps;

    const H266RawSPS *rsps = sl->sps;

    int ret;

    if (!rpps)

        return AVERROR_INVALIDDATA;

    if (!rsps)

        return AVERROR_INVALIDDATA;

    ret = decode_sps(ps, c, rsps, is_clvss);

    if (ret < 0)

        return ret;

    if (rsps->sps_log2_ctu_size_minus5 > 2) {

        // CTU > 128 are reserved in vvc spec v3

        av_log(c, AV_LOG_ERROR, "CTU size > 128. \n");

        return AVERROR_PATCHWELCOME;

    }

    ret = decode_pps(ps, rpps);

    if (ret < 0)

        return ret;

    return 0;

}

#define WEIGHT_TABLE(x)                                                                                 \

    w->nb_weights[L##x] = r->num_weights_l##x;                                                          \

    for (int i = 0; i < w->nb_weights[L##x]; i++) {                                                     \

        w->weight_flag[L##x][LUMA][i]     = r->luma_weight_l##x##_flag[i];                              \

        w->weight_flag[L##x][CHROMA][i]   = r->chroma_weight_l##x##_flag[i];                            \

        w->weight[L##x][LUMA][i]          = denom[LUMA] + r->delta_luma_weight_l##x[i];                 \

        w->offset[L##x][LUMA][i]          = r->luma_offset_l##x[i];                                     \

        for (int j = CB; j <= CR; j++) {                                                                \

            w->weight[L##x][j][i]         = denom[CHROMA] + r->delta_chroma_weight_l##x[i][j - 1];      \

            w->offset[L##x][j][i]         = 128 + r->delta_chroma_offset_l##x[i][j - 1];                \

            w->offset[L##x][j][i]        -= (128 * w->weight[L##x][j][i]) >> w->log2_denom[CHROMA];     \

            w->offset[L##x][j][i]         = av_clip_intp2(w->offset[L##x][j][i], 7);                    \

        }                                                                                               \

    }                                                                                                   \

static void pred_weight_table(PredWeightTable *w, const H266RawPredWeightTable *r)

{

    int denom[2];

    w->log2_denom[LUMA] = r->luma_log2_weight_denom;

    w->log2_denom[CHROMA] = w->log2_denom[LUMA] + r->delta_chroma_log2_weight_denom;

    denom[LUMA] = 1 << w->log2_denom[LUMA];

    denom[CHROMA] = 1 << w->log2_denom[CHROMA];

    WEIGHT_TABLE(0)

    WEIGHT_TABLE(1)

}

// 8.3.1 Decoding process for picture order count

static int ph_compute_poc(const H266RawPictureHeader *ph, const H266RawSPS *sps, const int poc_tid0, const int is_clvss)

{

    const int max_poc_lsb       = 1 << (sps->sps_log2_max_pic_order_cnt_lsb_minus4 + 4);

    const int prev_poc_lsb      = poc_tid0 % max_poc_lsb;

    const int prev_poc_msb      = poc_tid0 - prev_poc_lsb;

    const int poc_lsb           = ph->ph_pic_order_cnt_lsb;

    int poc_msb;

    if (ph->ph_poc_msb_cycle_present_flag) {

        poc_msb = ph->ph_poc_msb_cycle_val * max_poc_lsb;

    } else if (is_clvss) {

        poc_msb = 0;

    } else {

        if (poc_lsb < prev_poc_lsb && prev_poc_lsb - poc_lsb >= max_poc_lsb / 2)

            poc_msb = prev_poc_msb + max_poc_lsb;

        else if (poc_lsb > prev_poc_lsb && poc_lsb - prev_poc_lsb > max_poc_lsb / 2)

            poc_msb = prev_poc_msb - max_poc_lsb;

        else

            poc_msb = prev_poc_msb;

    }

    return poc_msb + poc_lsb;

}

static av_always_inline uint16_t lmcs_derive_lut_sample(uint16_t sample,

    uint16_t *pivot1, uint16_t *pivot2, uint16_t *scale_coeff, const int idx, const int max)

{

    const int lut_sample =

        pivot1[idx] + ((scale_coeff[idx] * (sample - pivot2[idx]) + (1<< 10)) >> 11);

    return av_clip(lut_sample, 0, max - 1);

}

//8.8.2.2 Inverse mapping process for a luma sample

static int lmcs_derive_lut(VVCLMCS *lmcs, const H266RawAPS *rlmcs, const H266RawSPS *sps)

{

    const int bit_depth = (sps->sps_bitdepth_minus8 + 8);

    const int max       = (1 << bit_depth);

    const int org_cw    = max / LMCS_MAX_BIN_SIZE;

    const int shift     = av_log2(org_cw);

    const int off       = 1 << (shift - 1);

    int cw[LMCS_MAX_BIN_SIZE];

    uint16_t input_pivot[LMCS_MAX_BIN_SIZE];

    uint16_t scale_coeff[LMCS_MAX_BIN_SIZE];

    uint16_t inv_scale_coeff[LMCS_MAX_BIN_SIZE];

    int i, delta_crs, sum_cw = 0;

    if (bit_depth > LMCS_MAX_BIT_DEPTH)

        return AVERROR_PATCHWELCOME;

    if (!rlmcs)

        return AVERROR_INVALIDDATA;

    lmcs->min_bin_idx = rlmcs->lmcs_min_bin_idx;

    lmcs->max_bin_idx = LMCS_MAX_BIN_SIZE - 1 - rlmcs->lmcs_delta_max_bin_idx;

    memset(cw, 0, sizeof(cw));

    for (int i = lmcs->min_bin_idx; i <= lmcs->max_bin_idx; i++) {

        cw[i] = org_cw + (1 - 2 * rlmcs->lmcs_delta_sign_cw_flag[i]) * rlmcs->lmcs_delta_abs_cw[i];

        sum_cw += cw[i];

    }

    if (sum_cw > (1 << bit_depth) - 1)

        return AVERROR_INVALIDDATA;

    delta_crs = (1 - 2 * rlmcs->lmcs_delta_sign_crs_flag) * rlmcs->lmcs_delta_abs_crs;

    lmcs->pivot[0] = 0;

    for (i = 0; i < LMCS_MAX_BIN_SIZE; i++) {

        input_pivot[i]        = i * org_cw;

        lmcs->pivot[i + 1] = lmcs->pivot[i] + cw[i];

        if (i >= lmcs->min_bin_idx && i <= lmcs->max_bin_idx &&

            lmcs->pivot[i] % (1 << (bit_depth - 5)) != 0 &&

            lmcs->pivot[i] >> (bit_depth - 5) == lmcs->pivot[i + 1] >> (bit_depth - 5))

            return AVERROR_INVALIDDATA;

        scale_coeff[i]        = (cw[i] * (1 << 11) +  off) >> shift;

        if (cw[i] == 0) {

            inv_scale_coeff[i] = 0;

            lmcs->chroma_scale_coeff[i] = (1 << 11);

        } else {

            const int cw_plus_d = cw[i] + delta_crs;

            if (cw_plus_d < (org_cw >> 3) || cw_plus_d > ((org_cw << 3) - 1))

                return AVERROR_INVALIDDATA;

            inv_scale_coeff[i] = org_cw * (1 << 11) / cw[i];

            lmcs->chroma_scale_coeff[i] = org_cw * (1 << 11) / cw_plus_d;

        }

    }

    //derive lmcs_fwd_lut

    for (uint16_t sample = 0; sample < max; sample++) {

        const int idx_y = sample >> shift;

        const uint16_t fwd_sample = lmcs_derive_lut_sample(sample, lmcs->pivot,

            input_pivot, scale_coeff, idx_y, max);

        if (bit_depth > 8)

            lmcs->fwd_lut.u16[sample] = fwd_sample;

        else

            lmcs->fwd_lut.u8 [sample] = fwd_sample;

    }

    //derive lmcs_inv_lut

    i = lmcs->min_bin_idx;

    for (uint16_t sample = 0; sample < max; sample++) {

        uint16_t inv_sample;

        while (i <= lmcs->max_bin_idx && sample >= lmcs->pivot[i + 1])

            i++;

        i = FFMIN(i, LMCS_MAX_BIN_SIZE - 1);

        inv_sample = lmcs_derive_lut_sample(sample, input_pivot, lmcs->pivot,

            inv_scale_coeff, i, max);

        if (bit_depth > 8)

            lmcs->inv_lut.u16[sample] = inv_sample;

        else

            lmcs->inv_lut.u8 [sample] = inv_sample;

    }

    return 0;

}

static int ph_max_num_subblock_merge_cand(const H266RawSPS *sps, const H266RawPictureHeader *ph)

{

    if (sps->sps_affine_enabled_flag)

        return 5 - sps->sps_five_minus_max_num_subblock_merge_cand;

    return sps->sps_sbtmvp_enabled_flag && ph->ph_temporal_mvp_enabled_flag;

}

static int ph_vb_pos(uint16_t *vbs, uint8_t *num_vbs, const uint16_t *pos_minus_1, const uint8_t num_pos, uint16_t max, const int ctb_size_y)

{

    max = FF_CEIL_RSHIFT(max, 3) - 2;

    for (int i = 0; i < num_pos; i++) {

        if (pos_minus_1[i] > max)

            return AVERROR_INVALIDDATA;

        vbs[i] = (pos_minus_1[i] + 1) << 3;

        // The distance between any two vertical virtual boundaries shall be greater than or equal to CtbSizeY luma samples

        if (i && vbs[i] < vbs[i - 1] + ctb_size_y)

            return AVERROR_INVALIDDATA;

    }

    *num_vbs = num_pos;

    return 0;

}

#define VBF(f) (sps->sps_virtual_boundaries_present_flag ? sps->sps_##f : ph->r->ph_##f)

#define VBFS(c, d) VBF(virtual_boundary_pos_##c##_minus1), VBF(num_##d##_virtual_boundaries)

static int ph_vb(VVCPH *ph, const H266RawSPS *sps, const H266RawPPS *pps)

{

    const int ctb_size_y = 1 << (sps->sps_log2_ctu_size_minus5 + 5);

    int ret;

    if (!sps->sps_virtual_boundaries_enabled_flag)

        return 0;

    ret = ph_vb_pos(ph->vb_pos_x, &ph->num_ver_vbs, VBFS(x, ver), pps->pps_pic_width_in_luma_samples, ctb_size_y);

    if (ret < 0)

        return ret;

    ret = ph_vb_pos(ph->vb_pos_y, &ph->num_hor_vbs, VBFS(y, hor), pps->pps_pic_height_in_luma_samples, ctb_size_y);

    if (ret < 0)

        return ret;

    return 0;

}

static int ph_derive(VVCPH *ph, const H266RawSPS *sps, const H266RawPPS *pps, const int poc_tid0, const int is_clvss)

{

    int ret;

    ph->max_num_subblock_merge_cand = ph_max_num_subblock_merge_cand(sps, ph->r);

    ph->poc = ph_compute_poc(ph->r, sps, poc_tid0, is_clvss);

    if (pps->pps_wp_info_in_ph_flag)

        pred_weight_table(&ph->pwt, &ph->r->ph_pred_weight_table);

    ret = ph_vb(ph, sps, pps);

    if (ret < 0)

        return ret;

    return 0;

}

static int decode_ph(VVCFrameParamSets *fps, const H266RawPictureHeader *rph, void *rph_ref,

    const int poc_tid0, const int is_clvss)

{

    int ret;

    VVCPH *ph = &fps->ph;

    const H266RawSPS *sps = fps->sps->r;

    const H266RawPPS *pps = fps->pps->r;

    ph->r = rph;

    av_refstruct_replace(&ph->rref, rph_ref);

    ret = ph_derive(ph, sps, pps, poc_tid0, is_clvss);

    if (ret < 0)

        return ret;

    return 0;

}

static int decode_frame_ps(VVCFrameParamSets *fps, const VVCParamSets *ps,

    const SliceContext *sc, const int poc_tid0, const int is_clvss, const VVCContext *s)

{

    const H266RawSlice *sl         = sc->ref;

    const H266RawPictureHeader *ph = sl->ph;

    const H266RawPPS *rpps         = sl->pps;

    int ret;

    if (!ph)

        return AVERROR_INVALIDDATA;

    if (!rpps)

        return AVERROR_INVALIDDATA;

    av_refstruct_replace(&fps->sps, ps->sps_list[rpps->pps_seq_parameter_set_id]);

    av_refstruct_replace(&fps->pps, ps->pps_list[rpps->pps_pic_parameter_set_id]);

    ret = decode_ph(fps, ph, sl->ph_ref, poc_tid0, is_clvss);

    if (ret < 0)

        return ret;

    if (ph->ph_explicit_scaling_list_enabled_flag)