FFmpeg  2.8.5
Macros | Functions
hash.h File Reference
#include <stdint.h>

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Macros

#define AV_HASH_MAX_SIZE   64
 Maximum value that av_hash_get_size will currently return. More...
 

Functions

int av_hash_alloc (struct AVHashContext **ctx, const char *name)
 Allocate a hash context for the algorithm specified by name. More...
 
const char * av_hash_names (int i)
 Get the names of available hash algorithms. More...
 
const char * av_hash_get_name (const struct AVHashContext *ctx)
 Get the name of the algorithm corresponding to the given hash context. More...
 
int av_hash_get_size (const struct AVHashContext *ctx)
 Get the size of the resulting hash value in bytes. More...
 
void av_hash_init (struct AVHashContext *ctx)
 Initialize or reset a hash context. More...
 
void av_hash_update (struct AVHashContext *ctx, const uint8_t *src, int len)
 Update a hash context with additional data. More...
 
void av_hash_final (struct AVHashContext *ctx, uint8_t *dst)
 Finalize a hash context and compute the actual hash value. More...
 
void av_hash_final_bin (struct AVHashContext *ctx, uint8_t *dst, int size)
 Finalize a hash context and compute the actual hash value. More...
 
void av_hash_final_hex (struct AVHashContext *ctx, uint8_t *dst, int size)
 Finalize a hash context and compute the actual hash value as a hex string. More...
 
void av_hash_final_b64 (struct AVHashContext *ctx, uint8_t *dst, int size)
 Finalize a hash context and compute the actual hash value as a base64 string. More...
 
void av_hash_freep (struct AVHashContext **ctx)
 Free hash context. More...
 

Macro Definition Documentation

#define AV_HASH_MAX_SIZE   64

Maximum value that av_hash_get_size will currently return.

You can use this if you absolutely want or need to use static allocation and are fine with not supporting hashes newly added to libavutil without recompilation. Note that you still need to check against av_hash_get_size, adding new hashes with larger sizes will not be considered an ABI change and should not cause your code to overflow a buffer.

Definition at line 61 of file hash.h.

Function Documentation

int av_hash_alloc ( struct AVHashContext **  ctx,
const char *  name 
)

Allocate a hash context for the algorithm specified by name.

Returns
>= 0 for success, a negative error code for failure
Note
The context is not initialized, you must call av_hash_init().
const char* av_hash_names ( int  i)

Get the names of available hash algorithms.

This function can be used to enumerate the algorithms.

Parameters
iindex of the hash algorithm, starting from 0
Returns
a pointer to a static string or NULL if i is out of range
const char* av_hash_get_name ( const struct AVHashContext *  ctx)

Get the name of the algorithm corresponding to the given hash context.

int av_hash_get_size ( const struct AVHashContext *  ctx)

Get the size of the resulting hash value in bytes.

The pointer passed to av_hash_final have space for at least this many bytes.

void av_hash_init ( struct AVHashContext *  ctx)

Initialize or reset a hash context.

void av_hash_update ( struct AVHashContext *  ctx,
const uint8_t *  src,
int  len 
)

Update a hash context with additional data.

void av_hash_final ( struct AVHashContext *  ctx,
uint8_t *  dst 
)

Finalize a hash context and compute the actual hash value.

void av_hash_final_bin ( struct AVHashContext *  ctx,
uint8_t *  dst,
int  size 
)

Finalize a hash context and compute the actual hash value.

If size is smaller than the hash size, the hash is truncated; if size is larger, the buffer is padded with 0.

void av_hash_final_hex ( struct AVHashContext *  ctx,
uint8_t *  dst,
int  size 
)

Finalize a hash context and compute the actual hash value as a hex string.

The string is always 0-terminated. If size is smaller than 2 * hash_size + 1, the hex string is truncated.

void av_hash_final_b64 ( struct AVHashContext *  ctx,
uint8_t *  dst,
int  size 
)

Finalize a hash context and compute the actual hash value as a base64 string.

The string is always 0-terminated. If size is smaller than AV_BASE64_SIZE(hash_size), the base64 string is truncated.

void av_hash_freep ( struct AVHashContext **  ctx)

Free hash context.