/* * 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 <stdint.h> #include <string.h> #include "libavutil/attributes.h" #include "libavutil/avassert.h" #include "rl.h" av_cold void ff_rl_init_level_run(uint8_t max_level[MAX_LEVEL + 1], uint8_t index_run[MAX_RUN + 1], const uint8_t table_run[/* n */], const uint8_t table_level[/* n*/], int n) { memset(index_run, n, MAX_RUN + 1); for (int i = 0; i < n; i++) { int run = table_run[i]; int level = table_level[i]; if (index_run[run] == n) index_run[run] = i; if (level > max_level[run]) max_level[run] = level; } } av_cold void ff_rl_init(RLTable *rl, uint8_t static_store[2][2 * MAX_RUN + MAX_LEVEL + 3]) { int last, run, level, start, end, i; /* compute max_level[], max_run[] and index_run[] */ for (last = 0; last < 2; last++) { int8_t *max_level = static_store[last]; int8_t *max_run = static_store[last] + MAX_RUN + 1; uint8_t *index_run = static_store[last] + MAX_RUN + 1 + MAX_LEVEL + 1; if (last == 0) { start = 0; end = rl->last; } else { start = rl->last; end = rl->n; } memset(index_run, rl->n, MAX_RUN + 1); for (i = start; i < end; i++) { run = rl->table_run[i]; level = rl->table_level[i]; if (index_run[run] == rl->n) index_run[run] = i; if (level > max_level[run]) max_level[run] = level; if (run > max_run[level]) max_run[level] = run; } rl->max_level[last] = max_level; rl->max_run[last] = max_run; rl->index_run[last] = index_run; } } av_cold void ff_rl_init_vlc(RLTable *rl, unsigned static_size) { int i, q; VLCElem table[1500] = { 0 }; VLC vlc = { .table = table, .table_allocated = static_size }; av_assert0(static_size <= FF_ARRAY_ELEMS(table)); vlc_init(&vlc, 9, rl->n + 1, &rl->table_vlc[0][1], 4, 2, &rl->table_vlc[0][0], 4, 2, VLC_INIT_USE_STATIC); for (q = 0; q < 32; q++) { int qmul = q * 2; int qadd = (q - 1) | 1; if (!rl->rl_vlc[q]) return; if (q == 0) { qmul = 1; qadd = 0; } for (i = 0; i < vlc.table_size; i++) { int code = vlc.table[i].sym; int len = vlc.table[i].len; int level, run; if (len == 0) { // illegal code run = 66; level = MAX_LEVEL; } else if (len < 0) { // more bits needed run = 0; level = code; } else { if (code == rl->n) { // esc run = 66; level = 0; } else { run = rl->table_run[code] + 1; level = rl->table_level[code] * qmul + qadd; if (code >= rl->last) run += 192; } } rl->rl_vlc[q][i].len = len; rl->rl_vlc[q][i].level = level; rl->rl_vlc[q][i].run = run; } } }