GNU Radio 3.6.5 C++ API

gr::digital::packet_header_default Class Reference

Default header formatter for digital packet transmission. More...

#include <packet_header_default.h>

Inheritance diagram for gr::digital::packet_header_default:
gr::digital::packet_header_ofdm

List of all members.

Public Types

typedef boost::shared_ptr
< packet_header_default
sptr

Public Member Functions

 packet_header_default (long header_len, const std::string &len_tag_key="packet_len", const std::string &num_tag_key="packet_num", int bits_per_byte=1)
 ~packet_header_default ()
sptr base ()
sptr formatter ()
void set_header_num (unsigned header_num)
long header_len ()
pmt::pmt_t len_tag_key ()
virtual bool header_formatter (long packet_len, unsigned char *out, const std::vector< gr_tag_t > &tags=std::vector< gr_tag_t >())
 Encodes the header information in the given tags into bits and places them into out.
virtual bool header_parser (const unsigned char *header, std::vector< gr_tag_t > &tags)
 Inverse function to header_formatter().

Static Public Member Functions

static sptr make (long header_len, const std::string &len_tag_key="packet_len", const std::string &num_tag_key="packet_num", int bits_per_byte=1)

Protected Attributes

long d_header_len
pmt::pmt_t d_len_tag_key
pmt::pmt_t d_num_tag_key
int d_bits_per_byte
unsigned d_header_number
unsigned d_mask

Detailed Description

Default header formatter for digital packet transmission.

For bursty/packetized digital transmission, packets are usually prepended with a packet header, containing the number of bytes etc. This class is not a block, but a tool to create these packet header.

This is a default packet header (see header_formatter()) for a description on the header format). To create other header, derive packet header creator classes from this function.

gr::digital::packet_headergenerator_bb uses header generators derived from this class to create packet headers from data streams.


Member Typedef Documentation


Constructor & Destructor Documentation

gr::digital::packet_header_default::packet_header_default ( long  header_len,
const std::string &  len_tag_key = "packet_len",
const std::string &  num_tag_key = "packet_num",
int  bits_per_byte = 1 
)
gr::digital::packet_header_default::~packet_header_default ( )

Member Function Documentation

sptr gr::digital::packet_header_default::base ( ) [inline]
sptr gr::digital::packet_header_default::formatter ( ) [inline]
virtual bool gr::digital::packet_header_default::header_formatter ( long  packet_len,
unsigned char *  out,
const std::vector< gr_tag_t > &  tags = std::vectorgr_tag_t >() 
) [virtual]

Encodes the header information in the given tags into bits and places them into out.

Uses the following header format: Bits 0-11: The packet length (what was stored in the tag with key len_tag_key) Bits 12-27: The header number (counts up everytime this function is called) Bit 28: Even parity bit All other bits: Are set to zero

If the header length is smaller than 29, bits are simply left out. For this reason, they always start with the LSB.

long gr::digital::packet_header_default::header_len ( ) [inline]
virtual bool gr::digital::packet_header_default::header_parser ( const unsigned char *  header,
std::vector< gr_tag_t > &  tags 
) [virtual]

Inverse function to header_formatter().

Reads the bit stream in header and writes a corresponding tag into tags.

Reimplemented in gr::digital::packet_header_ofdm.

pmt::pmt_t gr::digital::packet_header_default::len_tag_key ( ) [inline]
static sptr gr::digital::packet_header_default::make ( long  header_len,
const std::string &  len_tag_key = "packet_len",
const std::string &  num_tag_key = "packet_num",
int  bits_per_byte = 1 
) [static]
void gr::digital::packet_header_default::set_header_num ( unsigned  header_num) [inline]

Member Data Documentation


The documentation for this class was generated from the following file: