interval.c File Reference

Compute the interpretation interval for LSB and W-LSB encoding. More...

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

Include dependency graph for interval.c:

Functions
struct rohc_interval32	rohc_f_32bits (const uint32_t v_ref, const size_t k, const rohc_lsb_shift_t p)
	The f function as defined in LSB encoding for 32-bit fields. More...
int32_t	rohc_interval_get_rfc5225_msn_p (const size_t k, rohc_reordering_offset_t reorder_ratio)
	Get shift parameter p from number of bytes k and reorder ratio. More...
int32_t	rohc_interval_get_rfc5225_id_id_p (const size_t k)
	Get shift parameter p from number of bytes k for ip_id_lsb. More...

Detailed Description

Compute the interpretation interval for LSB and W-LSB encoding.

Author

Didier Barvaux didie.nosp@m.r.ba.nosp@m.rvaux.nosp@m.@tou.nosp@m.louse.nosp@m..viv.nosp@m.eris..nosp@m.com

Didier Barvaux didie.nosp@m.r@ba.nosp@m.rvaux.nosp@m..org

David Moreau from TAS

Function Documentation

rohc_f_32bits()

struct rohc_interval32 rohc_f_32bits	(	const uint32_t	v_ref,
		const size_t	k,
		const rohc_lsb_shift_t	p
	)

The f function as defined in LSB encoding for 32-bit fields.

Find out the interval [v_ref - p, v_ref + (2^k - 1) - p] for a given k. See 4.5.1 in the RFC 3095 for details.

As stated RFC, the values to be encoded have a finite range and the interpretation interval can straddle the wraparound boundary. So, the min value may be greater than the max value!

Parameters

v_ref	The reference value
k	The number of least significant bits of the value that are transmitted
p	The shift parameter (may be negative)

Returns

The computed interval

rohc_interval_get_rfc5225_id_id_p()

int32_t rohc_interval_get_rfc5225_id_id_p

(

const size_t

k

)

Get shift parameter p from number of bytes k for ip_id_lsb.

Parameters

k	The number of least significant bits of the value that are transmitted

Returns

The shift parameter p

rohc_interval_get_rfc5225_msn_p()

int32_t rohc_interval_get_rfc5225_msn_p	(	const size_t	k,
		rohc_reordering_offset_t	reorder_ratio
	)

Get shift parameter p from number of bytes k and reorder ratio.

Parameters

k	The number of least significant bits of the value that are transmitted
reorder_ratio	The reordering ratio

Returns

The shift parameter p