Murmur3

Граф связей класса Murmur3:

Файлы
файл	murmur3.h

Функции
struct AVMurMur3 *	av_murmur3_alloc (void)
void	av_murmur3_init_seeded (struct AVMurMur3 *c, uint64_t seed)
void	av_murmur3_init (struct AVMurMur3 *c)
void	av_murmur3_update (struct AVMurMur3 *c, const uint8_t *src, int len)
void	av_murmur3_update (struct AVMurMur3 *c, const uint8_t *src, size_t len)
void	av_murmur3_final (struct AVMurMur3 *c, uint8_t dst[16])

Подробное описание

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.

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.

Функции

av_murmur3_alloc()

struct AVMurMur3* av_murmur3_alloc

(

void

)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/murmur3.h>

Allocate an AVMurMur3 hash context.

Возвращает

Uninitialized hash context or NULL in case of error

av_murmur3_init_seeded()

void av_murmur3_init_seeded	(	struct AVMurMur3 *	c,
		uint64_t	seed
	)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/murmur3.h>

Initialize or reinitialize an AVMurMur3 hash context with a seed.

Аргументы

[out]	c	Hash context
[in]	seed	Random seed

См. также

av_murmur3_init()

Detailed description on a discussion of seeds for MurmurHash3.

av_murmur3_init()

void av_murmur3_init

(

struct AVMurMur3 *

c

)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/murmur3.h>

Initialize or reinitialize an AVMurMur3 hash context.

Equivalent to av_murmur3_init_seeded() with a built-in seed.

Аргументы

[out]

c

Hash context

См. также

av_murmur3_init_seeded()

Detailed description on a discussion of seeds for MurmurHash3.

av_murmur3_update() [1/2]

void av_murmur3_update	(	struct AVMurMur3 *	c,
		const uint8_t *	src,
		int	len
	)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/murmur3.h>

Update hash context with new data.

Аргументы

[out]	c	Hash context
[in]	src	Input data to update hash with
[in]	len	Number of bytes to read from src

av_murmur3_update() [2/2]

void av_murmur3_update	(	struct AVMurMur3 *	c,
		const uint8_t *	src,
		size_t	len
	)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/murmur3.h>

av_murmur3_final()

void av_murmur3_final	(	struct AVMurMur3 *	c,
		uint8_t	dst[16]
	)

#include <C:/git/world-of-might-and-magic/lib/win32/x86/ffmpeg-4.2.2/include/libavutil/murmur3.h>

Finish hashing and output digest value.

Аргументы

[in,out]	c	Hash context
[out]	dst	Buffer where output digest value is stored