ROHC compression/decompression library
Functions
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_interval16 rohc_f_16bits (const uint16_t v_ref, const size_t k, const rohc_lsb_shift_t p)
 The f function as defined in LSB encoding for 16-bit fields.
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.

Detailed Description

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

Author:
Didier Barvaux <didier.barvaux@toulouse.viveris.com>
Didier Barvaux <didier@barvaux.org>
David Moreau from TAS

Function Documentation

struct rohc_interval16 rohc_f_16bits ( const uint16_t  v_ref,
const size_t  k,
const rohc_lsb_shift_t  p 
) [read]

The f function as defined in LSB encoding for 16-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_refThe reference value
kThe number of least significant bits of the value that are transmitted
pThe shift parameter (may be negative)
Returns:
The computed interval
struct rohc_interval32 rohc_f_32bits ( const uint32_t  v_ref,
const size_t  k,
const rohc_lsb_shift_t  p 
) [read]

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_refThe reference value
kThe number of least significant bits of the value that are transmitted
pThe shift parameter (may be negative)
Returns:
The computed interval