diff options
Diffstat (limited to 'libavcodec/rl.c')
| -rw-r--r-- | libavcodec/rl.c | 119 |
1 files changed, 119 insertions, 0 deletions
diff --git a/libavcodec/rl.c b/libavcodec/rl.c new file mode 100644 index 0000000000..3dc8a541af --- /dev/null +++ b/libavcodec/rl.c @@ -0,0 +1,119 @@ +/* + * 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 "libavutil/attributes.h" + +#include "rl.h" + +av_cold void ff_init_rl(RLTable *rl, + uint8_t static_store[2][2 * MAX_RUN + MAX_LEVEL + 3]) +{ + int8_t max_level[MAX_RUN + 1], max_run[MAX_LEVEL + 1]; + uint8_t index_run[MAX_RUN + 1]; + int last, run, level, start, end, i; + + /* If table is static, we can quit if rl->max_level[0] is not NULL */ + if (static_store && rl->max_level[0]) + return; + + /* compute max_level[], max_run[] and index_run[] */ + for (last = 0; last < 2; last++) { + if (last == 0) { + start = 0; + end = rl->last; + } else { + start = rl->last; + end = rl->n; + } + + memset(max_level, 0, MAX_RUN + 1); + memset(max_run, 0, MAX_LEVEL + 1); + 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; + } + if (static_store) + rl->max_level[last] = static_store[last]; + else + rl->max_level[last] = av_malloc(MAX_RUN + 1); + memcpy(rl->max_level[last], max_level, MAX_RUN + 1); + if (static_store) + rl->max_run[last] = static_store[last] + MAX_RUN + 1; + else + rl->max_run[last] = av_malloc(MAX_LEVEL + 1); + memcpy(rl->max_run[last], max_run, MAX_LEVEL + 1); + if (static_store) + rl->index_run[last] = static_store[last] + MAX_RUN + MAX_LEVEL + 2; + else + rl->index_run[last] = av_malloc(MAX_RUN + 1); + memcpy(rl->index_run[last], index_run, MAX_RUN + 1); + } +} + +av_cold void ff_init_vlc_rl(RLTable *rl, unsigned static_size) +{ + int i, q; + VLC_TYPE table[1500][2] = {{0}}; + VLC vlc = { .table = table, .table_allocated = static_size }; + av_assert0(static_size <= FF_ARRAY_ELEMS(table)); + init_vlc(&vlc, 9, rl->n + 1, &rl->table_vlc[0][1], 4, 2, &rl->table_vlc[0][0], 4, 2, INIT_VLC_USE_NEW_STATIC); + + for (q = 0; q < 32; q++) { + int qmul = q * 2; + int qadd = (q - 1) | 1; + + if (q == 0) { + qmul = 1; + qadd = 0; + } + for (i = 0; i < vlc.table_size; i++) { + int code = vlc.table[i][0]; + int len = vlc.table[i][1]; + 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; + } + } +} |