| /* | |
| * Copyright (C) 2013 Reimar Döffinger <[email protected]> | |
| * | |
| * 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 | |
| */ | |
| /** | |
| * @file | |
| * @ingroup lavu_murmur3 | |
| * Public header for MurmurHash3 hash function implementation. | |
| */ | |
| /** | |
| * @defgroup lavu_murmur3 Murmur3 | |
| * @ingroup lavu_hash | |
| * MurmurHash3 hash function implementation. | |
| * | |
| * MurmurHash3 is a non-cryptographic hash function, of which three | |
| * incompatible versions were created by its inventor Austin Appleby: | |
| * | |
| * - 32-bit output | |
| * - 128-bit output for 32-bit platforms | |
| * - 128-bit output for 64-bit platforms | |
| * | |
| * FFmpeg only implements the last variant: 128-bit output designed for 64-bit | |
| * platforms. Even though the hash function was designed for 64-bit platforms, | |
| * the function in reality works on 32-bit systems too, only with reduced | |
| * performance. | |
| * | |
| * @anchor lavu_murmur3_seedinfo | |
| * By design, MurmurHash3 requires a seed to operate. In response to this, | |
| * libavutil provides two functions for hash initiation, one that requires a | |
| * seed (av_murmur3_init_seeded()) and one that uses a fixed arbitrary integer | |
| * as the seed, and therefore does not (av_murmur3_init()). | |
| * | |
| * To make hashes comparable, you should provide the same seed for all calls to | |
| * this hash function -- if you are supplying one yourself, that is. | |
| * | |
| * @{ | |
| */ | |
| /** | |
| * Allocate an AVMurMur3 hash context. | |
| * | |
| * @return Uninitialized hash context or `NULL` in case of error | |
| */ | |
| struct AVMurMur3 *av_murmur3_alloc(void); | |
| /** | |
| * Initialize or reinitialize an AVMurMur3 hash context with a seed. | |
| * | |
| * @param[out] c Hash context | |
| * @param[in] seed Random seed | |
| * | |
| * @see av_murmur3_init() | |
| * @see @ref lavu_murmur3_seedinfo "Detailed description" on a discussion of | |
| * seeds for MurmurHash3. | |
| */ | |
| void av_murmur3_init_seeded(struct AVMurMur3 *c, uint64_t seed); | |
| /** | |
| * Initialize or reinitialize an AVMurMur3 hash context. | |
| * | |
| * Equivalent to av_murmur3_init_seeded() with a built-in seed. | |
| * | |
| * @param[out] c Hash context | |
| * | |
| * @see av_murmur3_init_seeded() | |
| * @see @ref lavu_murmur3_seedinfo "Detailed description" on a discussion of | |
| * seeds for MurmurHash3. | |
| */ | |
| void av_murmur3_init(struct AVMurMur3 *c); | |
| /** | |
| * Update hash context with new data. | |
| * | |
| * @param[out] c Hash context | |
| * @param[in] src Input data to update hash with | |
| * @param[in] len Number of bytes to read from `src` | |
| */ | |
| void av_murmur3_update(struct AVMurMur3 *c, const uint8_t *src, size_t len); | |
| /** | |
| * Finish hashing and output digest value. | |
| * | |
| * @param[in,out] c Hash context | |
| * @param[out] dst Buffer where output digest value is stored | |
| */ | |
| void av_murmur3_final(struct AVMurMur3 *c, uint8_t dst[16]); | |
| /** | |
| * @} | |
| */ | |