lsb_decode.c File Reference

Least Significant Bits (LSB) decoding. More...

#include "lsb_decode.h"
#include "interval.h"
#include <assert.h>

Include dependency graph for lsb_decode.c:

Data Structures
struct	rohc_lsb_decode
	The Least Significant Bits (LSB) decoding object. More...
Functions
struct rohc_lsb_decode *	rohc_lsb_new (const rohc_lsb_shift_t p)
	Create a new Least Significant Bits (LSB) decoding context.
void	rohc_lsb_free (struct rohc_lsb_decode *const lsb)
	Destroy a given Least Significant Bits (LSB) decoding context.
bool	rohc_lsb_decode32 (const struct rohc_lsb_decode *const lsb, const uint32_t m, const size_t k, uint32_t *const decoded)
	Decode a 32-bit LSB-encoded value.
bool	rohc_lsb_decode16 (const struct rohc_lsb_decode *const lsb, const uint16_t m, const size_t k, uint16_t *const decoded)
	Decode a 16-bit LSB-encoded value.
void	rohc_lsb_set_ref (struct rohc_lsb_decode *const lsb, const uint32_t v_ref_d)
	Update the LSB reference value.
uint32_t	rohc_lsb_get_ref (struct rohc_lsb_decode *const lsb)
	Get the current LSB reference value.

---

Detailed Description

Least Significant Bits (LSB) decoding.

Author:

Didier Barvaux <didier.barvaux@toulouse.viveris.com>

Didier Barvaux <didier@barvaux.org>

The hackers from ROHC for Linux

---

Function Documentation

bool rohc_lsb_decode16	(	const struct rohc_lsb_decode *const	lsb,
		const uint16_t	m,
		const size_t	k,
		uint16_t *const	decoded
	)

Decode a 16-bit LSB-encoded value.

See rohc_lsb_decode32 for details.

Parameters:

lsb	The LSB object used to decode
m	The LSB value to decode
k	The length of the LSB value to decode
decoded	OUT: The decoded value

Returns:

true in case of success, false otherwise

References rohc_lsb_decode::is_init, and rohc_lsb_decode32().

Referenced by ip_id_offset_decode().

bool rohc_lsb_decode32	(	const struct rohc_lsb_decode *const	lsb,
		const uint32_t	m,
		const size_t	k,
		uint32_t *const	decoded
	)

Decode a 32-bit LSB-encoded value.

See 4.5.1 in the RFC 3095 for details about LSB encoding.

Parameters:

lsb	The LSB object used to decode
m	The LSB value to decode
k	The length of the LSB value to decode
decoded	OUT: The decoded value

Returns:

true in case of success, false otherwise

References rohc_lsb_decode::is_init, rohc_lsb_decode::p, rohc_f_32bits(), and rohc_lsb_decode::v_ref_d.

Referenced by rohc_lsb_decode16(), and ts_decode_scaled().

void rohc_lsb_free

(

struct rohc_lsb_decode *const

lsb

)

Destroy a given Least Significant Bits (LSB) decoding context.

See 4.5.1 in the RFC 3095 for details about LSB encoding.

Parameters:

lsb	The LSB decoding context to destroy

Referenced by d_rtp_create(), d_udp_create(), d_udp_lite_create(), ip_id_offset_free(), and rohc_ts_scaled_free().

uint32_t rohc_lsb_get_ref

(

struct rohc_lsb_decode *const

lsb

)

Get the current LSB reference value.

Parameters:

lsb	The LSB object

Returns:

The current reference value

References rohc_lsb_decode::is_init, and rohc_lsb_decode::v_ref_d.

Referenced by d_generic_get_sn(), and ts_decode_scaled().

struct rohc_lsb_decode* rohc_lsb_new

(

const rohc_lsb_shift_t

p

)

[read]

Create a new Least Significant Bits (LSB) decoding context.

See 4.5.1 in the RFC 3095 for details about LSB encoding.

Parameters:

p	The p value used to efficiently encode/decode the values

Returns:

The new LSB decoding context in case of success, NULL otherwise

References rohc_lsb_decode::is_init, and rohc_lsb_decode::p.

Referenced by d_create_sc(), d_ip_create(), d_rtp_create(), d_udp_create(), d_udp_lite_create(), and ip_id_offset_new().

void rohc_lsb_set_ref	(	struct rohc_lsb_decode *const	lsb,
		const uint32_t	v_ref_d
	)

Update the LSB reference value.

This function is called after a CRC success to update the last decoded value (for example, the SN value). See 4.5.1 in the RFC 3095 for details about LSB encoding.

Parameters:

lsb	The LSB object
v_ref_d	The new reference value

References rohc_lsb_decode::is_init, and rohc_lsb_decode::v_ref_d.

Referenced by ip_id_offset_set_ref(), and ts_update_context().