bitstream.h File Reference

Include file for the bitstream and derived classes. More...

#include <stdint.h>
#include <cstdio>
#include "bit_constants.h"

Go to the source code of this file.

Classes
class	bitstream
	Bit stream base class. More...
class	obitstream
	Output bit stream. More...
class	ibitstream
	Input bit stream. More...

Functions
static unsigned int	bit_size (int32_t i)
	Find size (on [0,32]) of the smallest # that can hold the integer i.
static unsigned int	bit_size (unsigned int u)
	Find size (on [1,32]) of the smallest # that can hold the unsigned int u.

Detailed Description

Include file for the bitstream and derived classes.

Function Documentation

bit_size() [1/2]

unsigned int bit_size ( int32_t i )

inlinestatic

Find size (on [0,32]) of the smallest # that can hold the integer i.

By our convention, [-1,0] require 1 bit, [-2,1] require 2 bits, [-4,-3, 2,3] require 3 bits, etc. This was implemented as loops, but we find we save a lot of compute cycles by laying it out as an explicit tree of tests.

Parameters

i	The number whose size is being checked.

Referenced by mexp_golomb_write().

bit_size() [2/2]

unsigned int bit_size ( unsigned int u )

inlinestatic

Find size (on [1,32]) of the smallest # that can hold the unsigned int u.

By our convention, [0,1] require 1 bit, [2,3] require 2 bits, [4,5, 6,7] require 3 bits, etc.

Parameters

u	The number whose size is being checked.