view dev/efr-bit-packing.c @ 183:452c1d5a6268

libgsmefr BFI w/o data: emit zero output after decoder reset In real-life usage, each EFR decoder session will most likely begin with lots of BFI frames before the first real frame arrives. However, because the spec-defined home state of the decoder is speech rather than CN, our regular logic for BFI w/o data would have to feed pseudorandom noise to the decoder (in the "fixed codebook excitation pulses" part), which is silly to do at the beginning of the decoder session right out of reset. Therefore, let's check reset_flag_old, and if we are still in the reset state, simply emit zero output.
author Mychaela Falconia <falcon@freecalypso.org>
date Tue, 03 Jan 2023 00:12:18 +0000
parents 9639a44ae2e7
children
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/*
 * We would like to generate our EFR RTP frame packing and unpacking code
 * using bitter and sweet utilities from libgsm, so we'll end up packing
 * and unpacking EFR just like good old FR.  However, because of our
 * slightly different approach, entering the spec file for bitter and sweet
 * manually would be tedious and error-prone, hence we are going to
 * generate it with this program.
 */

#include <stdio.h>
#include <stdlib.h>

#define	PRM_NO	57

/* table from ETSI EFR code */
static const unsigned bitno[PRM_NO] =
{
    7, 8, 9, 8, 6,                          /* LSP VQ          */
    9, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 5,  /* first subframe  */
    6, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 5,  /* second subframe */
    9, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 5,  /* third subframe  */
    6, 4, 4, 4, 4, 4, 4, 3, 3, 3, 3, 3, 5   /* fourth subframe */
};

main(argc, argv)
	char **argv;
{
	unsigned n;

	printf("EFR_MAGIC\t4\n");
	for (n = 0; n < PRM_NO; n++)
		printf("params[%u]\t%u\n", n, bitno[n]);
	exit(0);
}