fifo.h File Reference

a very simple circular buffer FIFO implementation More...

#include <stdint.h>
#include "avutil.h"
#include "attributes.h"

Go to the source code of this file.

Data Structures
struct	AVFifoBuffer

Functions
AVFifoBuffer *	av_fifo_alloc (unsigned int size)
	Initialize an AVFifoBuffer. More...
AVFifoBuffer *	av_fifo_alloc_array (size_t nmemb, size_t size)
	Initialize an AVFifoBuffer. More...
void	av_fifo_free (AVFifoBuffer *f)
	Free an AVFifoBuffer. More...
void	av_fifo_freep (AVFifoBuffer **f)
	Free an AVFifoBuffer and reset pointer to NULL. More...
void	av_fifo_reset (AVFifoBuffer *f)
	Reset the AVFifoBuffer to the state right after av_fifo_alloc, in particular it is emptied. More...
int	av_fifo_size (const AVFifoBuffer *f)
	Return the amount of data in bytes in the AVFifoBuffer, that is the amount of data you can read from it. More...
int	av_fifo_space (const AVFifoBuffer *f)
	Return the amount of space in bytes in the AVFifoBuffer, that is the amount of data you can write into it. More...
int	av_fifo_generic_peek_at (AVFifoBuffer *f, void *dest, int offset, int buf_size, void(*func)(void *, void *, int))
	Feed data at specific position from an AVFifoBuffer to a user-supplied callback. More...
int	av_fifo_generic_peek (AVFifoBuffer *f, void *dest, int buf_size, void(*func)(void *, void *, int))
	Feed data from an AVFifoBuffer to a user-supplied callback. More...
int	av_fifo_generic_read (AVFifoBuffer *f, void *dest, int buf_size, void(*func)(void *, void *, int))
	Feed data from an AVFifoBuffer to a user-supplied callback. More...
int	av_fifo_generic_write (AVFifoBuffer *f, void *src, int size, int(*func)(void *, void *, int))
	Feed data from a user-supplied callback to an AVFifoBuffer. More...
int	av_fifo_realloc2 (AVFifoBuffer *f, unsigned int size)
	Resize an AVFifoBuffer. More...
int	av_fifo_grow (AVFifoBuffer *f, unsigned int additional_space)
	Enlarge an AVFifoBuffer. More...
void	av_fifo_drain (AVFifoBuffer *f, int size)
	Read and discard the specified amount of data from an AVFifoBuffer. More...
static uint8_t *	av_fifo_peek2 (const AVFifoBuffer *f, int offs)
	Return a pointer to the data stored in a FIFO buffer at a certain offset. More...

Detailed Description

a very simple circular buffer FIFO implementation

Definition in file fifo.h.

Function Documentation

av_fifo_alloc()

AVFifoBuffer* av_fifo_alloc

(

unsigned int

size

)

Initialize an AVFifoBuffer.

Parameters

size

of FIFO

Returns

AVFifoBuffer or NULL in case of memory allocation failure

av_fifo_alloc_array()

AVFifoBuffer* av_fifo_alloc_array	(	size_t	nmemb,
		size_t	size
	)

Initialize an AVFifoBuffer.

Parameters

nmemb	number of elements
size	size of the single element

Returns

AVFifoBuffer or NULL in case of memory allocation failure

av_fifo_free()

void av_fifo_free

(

AVFifoBuffer *

f

)

Free an AVFifoBuffer.

Parameters

f	AVFifoBuffer to free

av_fifo_freep()

void av_fifo_freep

(

AVFifoBuffer **

f

)

Free an AVFifoBuffer and reset pointer to NULL.

Parameters

f	AVFifoBuffer to free

av_fifo_reset()

void av_fifo_reset

(

AVFifoBuffer *

f

)

Reset the AVFifoBuffer to the state right after av_fifo_alloc, in particular it is emptied.

Parameters

f	AVFifoBuffer to reset

av_fifo_size()

int av_fifo_size

(

const AVFifoBuffer *

f

)

Return the amount of data in bytes in the AVFifoBuffer, that is the amount of data you can read from it.

Parameters

f	AVFifoBuffer to read from

Returns

size

av_fifo_space()

int av_fifo_space

(

const AVFifoBuffer *

f

)

Return the amount of space in bytes in the AVFifoBuffer, that is the amount of data you can write into it.

Parameters

f	AVFifoBuffer to write into

Returns

size

av_fifo_generic_peek_at()

int av_fifo_generic_peek_at	(	AVFifoBuffer *	f,
		void *	dest,
		int	offset,
		int	buf_size,
		void(*)(void *, void *, int)	func
	)

Feed data at specific position from an AVFifoBuffer to a user-supplied callback.

Similar as av_fifo_gereric_read but without discarding data.

Parameters

f	AVFifoBuffer to read from
offset	offset from current read position
buf_size	number of bytes to read
func	generic read function
dest	data destination

av_fifo_generic_peek()

int av_fifo_generic_peek	(	AVFifoBuffer *	f,
		void *	dest,
		int	buf_size,
		void(*)(void *, void *, int)	func
	)

Feed data from an AVFifoBuffer to a user-supplied callback.

Similar as av_fifo_gereric_read but without discarding data.

Parameters

f	AVFifoBuffer to read from
buf_size	number of bytes to read
func	generic read function
dest	data destination

av_fifo_generic_read()

int av_fifo_generic_read	(	AVFifoBuffer *	f,
		void *	dest,
		int	buf_size,
		void(*)(void *, void *, int)	func
	)

Feed data from an AVFifoBuffer to a user-supplied callback.

Parameters

f	AVFifoBuffer to read from
buf_size	number of bytes to read
func	generic read function
dest	data destination

av_fifo_generic_write()

int av_fifo_generic_write	(	AVFifoBuffer *	f,
		void *	src,
		int	size,
		int(*)(void *, void *, int)	func
	)

Feed data from a user-supplied callback to an AVFifoBuffer.

Parameters

f	AVFifoBuffer to write to
src	data source; non-const since it may be used as a modifiable context by the function defined in func
size	number of bytes to write
func	generic write function; the first parameter is src, the second is dest_buf, the third is dest_buf_size. func must return the number of bytes written to dest_buf, or <= 0 to indicate no more data available to write. If func is NULL, src is interpreted as a simple byte array for source data.

Returns

the number of bytes written to the FIFO

av_fifo_realloc2()

int av_fifo_realloc2	(	AVFifoBuffer *	f,
		unsigned int	size
	)

Resize an AVFifoBuffer.

In case of reallocation failure, the old FIFO is kept unchanged.

Parameters

f	AVFifoBuffer to resize
size	new AVFifoBuffer size in bytes

Returns

<0 for failure, >=0 otherwise

av_fifo_grow()

int av_fifo_grow	(	AVFifoBuffer *	f,
		unsigned int	additional_space
	)

Enlarge an AVFifoBuffer.

In case of reallocation failure, the old FIFO is kept unchanged. The new fifo size may be larger than the requested size.

Parameters

f	AVFifoBuffer to resize
additional_space	the amount of space in bytes to allocate in addition to av_fifo_size()

Returns

<0 for failure, >=0 otherwise

av_fifo_drain()

void av_fifo_drain	(	AVFifoBuffer *	f,
		int	size
	)

Read and discard the specified amount of data from an AVFifoBuffer.

Parameters

f	AVFifoBuffer to read from
size	amount of data to read in bytes

av_fifo_peek2()

static uint8_t* av_fifo_peek2 ( const AVFifoBuffer *  f, int  offs  )

inlinestatic

Return a pointer to the data stored in a FIFO buffer at a certain offset.

The FIFO buffer is not modified.

Parameters

f	AVFifoBuffer to peek at, f must be non-NULL
offs	an offset in bytes, its absolute value must be less than the used buffer size or the returned pointer will point outside to the buffer data. The used buffer size can be checked with av_fifo_size().

Definition at line 169 of file fifo.h.