Scroll to navigation

RQ_SYMBOL(3) Librecast Programmer's Manual RQ_SYMBOL(3)

NAME

rq_symbol - generate RaptorQ encoding symbol

SYNOPSIS

#include <lcrq.h>
int rq_symbol(rq_t *rq, rq_pid_t *pid, uint8_t *sym, int flags);

Compile and link with -llcrq.

DESCRIPTION

Generates a RaptorQ encoding symbol ready for sending.

Before calling rq_symbol() the intermediate symbols must first be created with a call to rq_encode(3).

rq must be a pointer to valid rq_t context

pid will be set to the FEC payload ID as per Section 3.2 of RFC6330:

0                   1                   2                   3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|     SBN       |               Encoding Symbol ID              |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

SBN (Source Block Number) is an 8 bit unsigned integer. The Encoding Symbol ID (ESI) is a 24 bit unsigned integer in network byte order.

On success, sym will be a pointer to the encoding symbol.

flags can be set to:

Generate a random repair symbol instead of returning the next ESI.

RETURN VALUE

Returns a pointer to the encoded symbol.

ERRORS

None.

SEE ALSO

rq_init(3), rq_free(3), rq_encode(3), rq_decode(3), rq_query(3), lcrq(7), errno(3)

2022-07-07 LCRQ