/* * FFv1 codec * * Copyright (c) 2024 Lynne * * 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; #if !defined(DECODE) PutBitContext pb; /* 8*8 bytes */ #else GetBitContext gb; #endif ivec2 slice_dim; ivec2 slice_pos; ivec2 slice_rct_coef; u8vec3 quant_table_idx; uint hdr_len; // only used for golomb uint slice_coding_mode; bool slice_reset_contexts; }; /* -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, }; uint slice_coord(uint width, uint sx, uint num_h_slices, uint chroma_shift) { uint mpw = 1 << chroma_shift; uint awidth = align(width, mpw); if ((version < 4) || ((version == 4) && (micro_version < 3))) return width * sx / num_h_slices; sx = (2 * awidth * sx + num_h_slices * mpw) / (2 * num_h_slices * mpw) * mpw; if (sx == awidth) sx = width; return sx; } #ifdef RGB #define RGB_LBUF (RGB_LINECACHE - 1) #define LADDR(p) (ivec2((p).x, ((p).y & RGB_LBUF))) ivec2 get_pred(readonly uimage2D pred, ivec2 sp, ivec2 off, int comp, int sw, uint8_t quant_table_idx, bool extend_lookup) { const ivec2 yoff_border1 = expectEXT(off.x == 0, false) ? off + ivec2(1, -1) : off; /* Thanks to the same coincidence as below, we can skip checking if off == 0, 1 */ VTYPE3 top = VTYPE3(TYPE(imageLoad(pred, sp + LADDR(yoff_border1 + ivec2(-1, -1)))[comp]), TYPE(imageLoad(pred, sp + LADDR(off + ivec2(0, -1)))[comp]), TYPE(imageLoad(pred, sp + LADDR(off + ivec2(min(1, sw - off.x - 1), -1)))[comp])); /* Normally, we'd need to check if off != ivec2(0, 0) here, since otherwise, we must * return zero. However, ivec2(-1, 0) + ivec2(1, -1) == ivec2(0, -1), e.g. previous * row, 0 offset, same slice, which is zero since we zero out the buffer for RGB */ TYPE cur = TYPE(imageLoad(pred, sp + LADDR(yoff_border1 + ivec2(-1, 0)))[comp]); int base = quant_table[quant_table_idx][0][(cur - top[0]) & MAX_QUANT_TABLE_MASK] + quant_table[quant_table_idx][1][(top[0] - top[1]) & MAX_QUANT_TABLE_MASK] + quant_table[quant_table_idx][2][(top[1] - top[2]) & MAX_QUANT_TABLE_MASK]; if (expectEXT(extend_lookup, false)) { TYPE cur2 = TYPE(0); if (expectEXT(off.x > 0, true)) { const ivec2 yoff_border2 = expectEXT(off.x == 1, false) ? ivec2(-1, -1) : ivec2(-2, 0); cur2 = TYPE(imageLoad(pred, sp + LADDR(off + yoff_border2))[comp]); } base += quant_table[quant_table_idx][3][(cur2 - cur) & MAX_QUANT_TABLE_MASK]; /* top-2 became current upon swap */ TYPE top2 = TYPE(imageLoad(pred, sp + LADDR(off))[comp]); base += quant_table[quant_table_idx][4][(top2 - top[1]) & MAX_QUANT_TABLE_MASK]; } /* context, prediction */ return ivec2(base, predict(cur, VTYPE2(top))); } #else /* RGB */ #define LADDR(p) (p) ivec2 get_pred(readonly uimage2D pred, ivec2 sp, ivec2 off, int comp, int sw, uint8_t quant_table_idx, bool extend_lookup) { const ivec2 yoff_border1 = off.x == 0 ? ivec2(1, -1) : ivec2(0, 0); sp += off; VTYPE3 top = VTYPE3(TYPE(0), TYPE(0), TYPE(0)); if (off.y > 0 && off != ivec2(0, 1)) top[0] = TYPE(imageLoad(pred, sp + ivec2(-1, -1) + yoff_border1)[comp]); if (off.y > 0) { top[1] = TYPE(imageLoad(pred, sp + ivec2(0, -1))[comp]); top[2] = TYPE(imageLoad(pred, sp + ivec2(min(1, sw - off.x - 1), -1))[comp]); } TYPE cur = TYPE(0); if (off != ivec2(0, 0)) cur = TYPE(imageLoad(pred, sp + ivec2(-1, 0) + yoff_border1)[comp]); int base = quant_table[quant_table_idx][0][(cur - top[0]) & MAX_QUANT_TABLE_MASK] + quant_table[quant_table_idx][1][(top[0] - top[1]) & MAX_QUANT_TABLE_MASK] + quant_table[quant_table_idx][2][(top[1] - top[2]) & MAX_QUANT_TABLE_MASK]; if (expectEXT(extend_lookup, false)) { TYPE cur2 = TYPE(0); if (off.x > 0 && off != ivec2(1, 0)) { const ivec2 yoff_border2 = off.x == 1 ? ivec2(1, -1) : ivec2(0, 0); cur2 = TYPE(imageLoad(pred, sp + ivec2(-2, 0) + yoff_border2)[comp]); } base += quant_table[quant_table_idx][3][(cur2 - cur) & MAX_QUANT_TABLE_MASK]; TYPE top2 = TYPE(0); if (off.y > 1) top2 = TYPE(imageLoad(pred, sp + ivec2(0, -2))[comp]); base += quant_table[quant_table_idx][4][(top2 - top[1]) & MAX_QUANT_TABLE_MASK]; } /* context, prediction */ return ivec2(base, predict(cur, VTYPE2(top))); } #endif