Self-Describing Variable-Length (SDVL) encoding. More...

#include "sdvl.h"
#include "rohc_bit_ops.h"
#include <assert.h>

Include dependency graph for sdvl.c:

Enumerations
enum	rohc_sdvl_max_value_t { ROHC_SDVL_MAX_VALUE_IN_1_BYTE = ((1 << ROHC_SDVL_MAX_BITS_IN_1_BYTE) - 1), ROHC_SDVL_MAX_VALUE_IN_2_BYTES = ((1 << ROHC_SDVL_MAX_BITS_IN_2_BYTES) - 1), ROHC_SDVL_MAX_VALUE_IN_3_BYTES = ((1 << ROHC_SDVL_MAX_BITS_IN_3_BYTES) - 1), ROHC_SDVL_MAX_VALUE_IN_4_BYTES = ((1 << ROHC_SDVL_MAX_BITS_IN_4_BYTES) - 1) }
Functions
bool	sdvl_can_value_be_encoded (const uint32_t value)
	Can the given value be encoded with SDVL?
bool	sdvl_can_length_be_encoded (const size_t bits_nr)
	Is the given length (in bits) compatible with SDVL?
size_t	sdvl_get_min_len (const size_t nr_min_required, const size_t nr_encoded)
	Find out how many SDVL bits are needed to represent a value.
size_t	sdvl_get_encoded_len (const uint32_t value)
	Find out how many bytes are needed to represent the value using Self-Describing Variable-Length (SDVL) encoding.
bool	sdvl_encode (uint8_t const sdvl_bytes, const size_t sdvl_bytes_max_nr, size_t const sdvl_bytes_nr, const uint32_t value, const size_t bits_nr)
	Encode a value using Self-Describing Variable-Length (SDVL) encoding.
bool	sdvl_encode_full (uint8_t const sdvl_bytes, const size_t sdvl_bytes_max_nr, size_t const sdvl_bytes_nr, const uint32_t value)
	Encode a value using Self-Describing Variable-Length (SDVL) encoding.
size_t	sdvl_decode (const uint8_t const data, const size_t length, uint32_t const value, size_t *const bits_nr)
	Decode a Self-Describing Variable-Length (SDVL) value.

Detailed Description

Self-Describing Variable-Length (SDVL) encoding.

Author:: Didier Barvaux <didier.barvaux@toulouse.viveris.com>; Didier Barvaux <didier@barvaux.org>

Enumeration Type Documentation

enum rohc_sdvl_max_value_t

The maximum values that can be SDVL-encoded in 1, 2, 3 and 4 bytes

Enumerator:

ROHC_SDVL_MAX_VALUE_IN_1_BYTE	Maximum value in 1 SDVL-encoded byte
ROHC_SDVL_MAX_VALUE_IN_2_BYTES	Maximum value in 2 SDVL-encoded byte
ROHC_SDVL_MAX_VALUE_IN_3_BYTES	Maximum value in 3 SDVL-encoded byte
ROHC_SDVL_MAX_VALUE_IN_4_BYTES	Maximum value in 4 SDVL-encoded byte

Function Documentation

bool sdvl_can_length_be_encoded ( const size_t bits_nr )

Is the given length (in bits) compatible with SDVL?

See 4.5.6 in the RFC 3095 for details about SDVL encoding.

Parameters:

bits_nr The length (in bits) of the value to encode

Returns:: Whether the value can be encoded with SDVL or not

bool sdvl_can_value_be_encoded ( const uint32_t value )

Can the given value be encoded with SDVL?

See 4.5.6 in the RFC 3095 for details about SDVL encoding.

Parameters:

value The value to encode

Returns:: Whether the value can be encoded with SDVL or not

size_t sdvl_decode	(	const uint8_t *const	data,
		const size_t	length,
		uint32_t *const	value,
		size_t *const	bits_nr
	)

Decode a Self-Describing Variable-Length (SDVL) value.

See 4.5.6 in the RFC 3095 for details about SDVL encoding.

Parameters:

data	The SDVL data to decode
length	The maximum data length available (in bytes)
value	OUT: The decoded value
bits_nr	OUT: The number of useful bits

Returns:: The number of bytes used by the SDVL field (value between 1 and 4), 0 in case of problem

bool sdvl_encode	(	uint8_t *const	sdvl_bytes,
		const size_t	sdvl_bytes_max_nr,
		size_t *const	sdvl_bytes_nr,
		const uint32_t	value,
		const size_t	bits_nr
	)

Encode a value using Self-Describing Variable-Length (SDVL) encoding.

See 4.5.6 in the RFC 3095 for details about SDVL encoding.

Encoding failures may be due to a value greater than 2^29.

Parameters:

sdvl_bytes	IN/OUT: The SDVL-encoded bytes
sdvl_bytes_max_nr	The maximum available free bytes for SDVL
sdvl_bytes_nr	OUT: The number of SDVL bytes written
value	The value to encode
bits_nr	The number of bits to encode

Returns:: true if SDVL encoding is successful, false in case of failure

bool sdvl_encode_full	(	uint8_t *const	sdvl_bytes,
		const size_t	sdvl_bytes_max_nr,
		size_t *const	sdvl_bytes_nr,
		const uint32_t	value
	)

Encode a value using Self-Describing Variable-Length (SDVL) encoding.

See 4.5.6 in the RFC 3095 for details about SDVL encoding.

Encoding failures may be due to a value greater than 2^29.

Parameters:

sdvl_bytes	IN/OUT: The SDVL-encoded bytes
sdvl_bytes_max_nr	The maximum available free bytes for SDVL
sdvl_bytes_nr	OUT: The number of SDVL bytes written
value	The value to encode

Returns:: true if SDVL encoding is successful, false in case of failure

size_t sdvl_get_encoded_len ( const uint32_t value )

Find out how many bytes are needed to represent the value using Self-Describing Variable-Length (SDVL) encoding.

See 4.5.6 in the RFC 3095 for details about SDVL encoding.

Parameters:

value The value to encode

Returns:: The size needed to represent the SDVL-encoded value

size_t sdvl_get_min_len	(	const size_t	nr_min_required,
		const size_t	nr_encoded
	)

Find out how many SDVL bits are needed to represent a value.

The number of bits already encoded in another field may be specified.

See 4.5.6 in the RFC 3095 for details about SDVL encoding.

Parameters:

nr_min_required	The minimum required number of bits to encode
nr_encoded	The number of bits already encoded in another field

Returns:: The number of bits needed to encode the value

Enumerations

Functions

Detailed Description

Enumeration Type Documentation

Function Documentation