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Diffstat (limited to '')
| -rw-r--r-- | media/ffvpx/libavcodec/vlc.h | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/media/ffvpx/libavcodec/vlc.h b/media/ffvpx/libavcodec/vlc.h new file mode 100644 index 0000000000..e63c484755 --- /dev/null +++ b/media/ffvpx/libavcodec/vlc.h @@ -0,0 +1,144 @@ +/* + * 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 + */ + +#ifndef AVCODEC_VLC_H +#define AVCODEC_VLC_H + +#include <stdint.h> + +// When changing this, be sure to also update tableprint_vlc.h accordingly. +typedef int16_t VLCBaseType; + +typedef struct VLCElem { + VLCBaseType sym, len; +} VLCElem; + +typedef struct VLC { + int bits; + VLCElem *table; + int table_size, table_allocated; +} VLC; + +typedef struct RL_VLC_ELEM { + int16_t level; + int8_t len; + uint8_t run; +} RL_VLC_ELEM; + +#define init_vlc(vlc, nb_bits, nb_codes, \ + bits, bits_wrap, bits_size, \ + codes, codes_wrap, codes_size, \ + flags) \ + ff_init_vlc_sparse(vlc, nb_bits, nb_codes, \ + bits, bits_wrap, bits_size, \ + codes, codes_wrap, codes_size, \ + NULL, 0, 0, flags) + +int ff_init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes, + const void *bits, int bits_wrap, int bits_size, + const void *codes, int codes_wrap, int codes_size, + const void *symbols, int symbols_wrap, int symbols_size, + int flags); + +/** + * Build VLC decoding tables suitable for use with get_vlc2() + * + * This function takes lengths and symbols and calculates the codes from them. + * For this the input lengths and symbols have to be sorted according to "left + * nodes in the corresponding tree first". + * + * @param[in,out] vlc The VLC to be initialized; table and table_allocated + * must have been set when initializing a static VLC, + * otherwise this will be treated as uninitialized. + * @param[in] nb_bits The number of bits to use for the VLC table; + * higher values take up more memory and cache, but + * allow to read codes with fewer reads. + * @param[in] nb_codes The number of provided length and (if supplied) symbol + * entries. + * @param[in] lens The lengths of the codes. Entries > 0 correspond to + * valid codes; entries == 0 will be skipped and entries + * with len < 0 indicate that the tree is incomplete and + * has an open end of length -len at this position. + * @param[in] lens_wrap Stride (in bytes) of the lengths. + * @param[in] symbols The symbols, i.e. what is returned from get_vlc2() + * when the corresponding code is encountered. + * May be NULL, then 0, 1, 2, 3, 4,... will be used. + * @param[in] symbols_wrap Stride (in bytes) of the symbols. + * @param[in] symbols_size Size of the symbols. 1 and 2 are supported. + * @param[in] offset An offset to apply to all the valid symbols. + * @param[in] flags A combination of the INIT_VLC_* flags; notice that + * INIT_VLC_INPUT_LE is pointless and ignored. + */ +int ff_init_vlc_from_lengths(VLC *vlc, int nb_bits, int nb_codes, + const int8_t *lens, int lens_wrap, + const void *symbols, int symbols_wrap, int symbols_size, + int offset, int flags, void *logctx); + +void ff_free_vlc(VLC *vlc); + +/* If INIT_VLC_INPUT_LE is set, the LSB bit of the codes used to + * initialize the VLC table is the first bit to be read. */ +#define INIT_VLC_INPUT_LE 2 +/* If set the VLC is intended for a little endian bitstream reader. */ +#define INIT_VLC_OUTPUT_LE 8 +#define INIT_VLC_LE (INIT_VLC_INPUT_LE | INIT_VLC_OUTPUT_LE) +#define INIT_VLC_USE_NEW_STATIC 4 +#define INIT_VLC_STATIC_OVERLONG (1 | INIT_VLC_USE_NEW_STATIC) + +#define INIT_CUSTOM_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, \ + h, i, j, flags, static_size) \ + do { \ + static VLCElem table[static_size]; \ + (vlc)->table = table; \ + (vlc)->table_allocated = static_size; \ + ff_init_vlc_sparse(vlc, bits, a, b, c, d, e, f, g, h, i, j, \ + flags | INIT_VLC_USE_NEW_STATIC); \ + } while (0) + +#define INIT_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, h, i, j, static_size) \ + INIT_CUSTOM_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, \ + h, i, j, 0, static_size) + +#define INIT_LE_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, h, i, j, static_size) \ + INIT_CUSTOM_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, \ + h, i, j, INIT_VLC_LE, static_size) + +#define INIT_CUSTOM_VLC_STATIC(vlc, bits, a, b, c, d, e, f, g, flags, static_size) \ + INIT_CUSTOM_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, \ + NULL, 0, 0, flags, static_size) + +#define INIT_VLC_STATIC(vlc, bits, a, b, c, d, e, f, g, static_size) \ + INIT_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, NULL, 0, 0, static_size) + +#define INIT_LE_VLC_STATIC(vlc, bits, a, b, c, d, e, f, g, static_size) \ + INIT_LE_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, NULL, 0, 0, static_size) + +#define INIT_VLC_STATIC_FROM_LENGTHS(vlc, bits, nb_codes, lens, len_wrap, \ + symbols, symbols_wrap, symbols_size, \ + offset, flags, static_size) \ + do { \ + static VLCElem table[static_size]; \ + (vlc)->table = table; \ + (vlc)->table_allocated = static_size; \ + ff_init_vlc_from_lengths(vlc, bits, nb_codes, lens, len_wrap, \ + symbols, symbols_wrap, symbols_size, \ + offset, flags | INIT_VLC_USE_NEW_STATIC, \ + NULL); \ + } while (0) + +#endif /* AVCODEC_VLC_H */ |