/* * FFv1 codec * * Copyright (c) 2024 Lynne <dev@lynne.ee> * * 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 */ struct SliceContext {    RangeCoder c; #ifdef GOLOMB    PutBitContext pb; /* 8*8 bytes */#endif     ivec2 slice_dim;    ivec2 slice_pos;    ivec2 slice_rct_coef;     uint hdr_len; // only used for golomb    int slice_coding_mode;}; /* -1, { -1, 0 } */int predict(int L, ivec2 top){    return mid_pred(L, L + top[1] - top[0], top[1]);} /* { -2, -1 }, { -1, 0, 1 }, 0 */int get_context(VTYPE2 cur_l, VTYPE3 top_l, TYPE top2, uint8_t quant_table_idx){    const int LT = top_l[0]; /* -1 */    const int T  = top_l[1]; /*  0 */    const int RT = top_l[2]; /*  1 */    const int L  = cur_l[1]; /* -1 */     int base = quant_table[quant_table_idx][0][(L - LT) & MAX_QUANT_TABLE_MASK] +               quant_table[quant_table_idx][1][(LT - T) & MAX_QUANT_TABLE_MASK] +               quant_table[quant_table_idx][2][(T - RT) & MAX_QUANT_TABLE_MASK];     if ((quant_table[quant_table_idx][3][127] == 0) &&        (quant_table[quant_table_idx][4][127] == 0))        return base;     const int TT = top2;     /* -2 */    const int LL = cur_l[0]; /* -2 */    return base +           quant_table[quant_table_idx][3][(LL - L) & MAX_QUANT_TABLE_MASK] +           quant_table[quant_table_idx][4][(TT - T) & MAX_QUANT_TABLE_MASK];} const uint32_t log2_run[41] = {     0,  0,  0,  0,  1,  1,  1,  1,     2,  2,  2,  2,  3,  3,  3,  3,     4,  4,  5,  5,  6,  6,  7,  7,     8,  9, 10, 11, 12, 13, 14, 15,    16, 17, 18, 19, 20, 21, 22, 23,    24,};