nest-open-source / manifest_repos / ffmpeg / 62cf23d89db2251203d6207e2261ddc5498167c6 / . / libavcodec / vlc.h

/* | |

* 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> | |

#define VLC_TYPE int16_t | |

typedef struct VLC { | |

int bits; | |

VLC_TYPE (*table)[2]; ///< code, bits | |

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 VLC_TYPE table[static_size][2]; \ | |

(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 VLC_TYPE table[static_size][2]; \ | |

(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 */ |