view amrconv/cod-read.c @ 492:cc3a831712a4

libgsmhr1: implement arbitrary RTP input
author Mychaela Falconia <falcon@freecalypso.org>
date Sat, 15 Jun 2024 06:52:37 +0000
parents 0beafaa0623f
children
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/*
 * In this module we implement utility functions for reading ETSI/3GPP
 * *.cod files (AMR version) in either LE or BE format.
 */

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include "amr_defs.h"

read_cod_bits(inf, big_endian, bitvec, filename_for_errs)
	FILE *inf;
	uint8_t *bitvec;
	char *filename_for_errs;
{
	uint8_t file_bytes[COD_FORMAT_NWORDS * 2], *sp;
	int cc;
	unsigned n, upper;

	cc = fread(file_bytes, 2, COD_FORMAT_NWORDS, inf);
	if (cc == 0)
		return 0;
	if (cc != COD_FORMAT_NWORDS) {
		fprintf(stderr, "error: short read from %s\n",
			filename_for_errs);
		exit(1);
	}
	sp = file_bytes;
	for (n = 0; n < COD_FORMAT_NWORDS; n++) {
		if (big_endian) {
			upper = sp[0];
			bitvec[n] = sp[1];
		} else {
			bitvec[n] = sp[0];
			upper = sp[1];
		}
		if (upper && (sp[0] != 0xFF || sp[1] != 0xFF)) {
			fprintf(stderr,
		"error in %s: non-zero in what should be %s upper byte\n",
				filename_for_errs, big_endian ? "BE" : "LE");
			exit(1);
		}
		sp += 2;
	}
	return 1;
}

void
preen_frame_bits(input_bits, nbits, filename_for_errs, frame_no)
	uint8_t *input_bits;
	char *filename_for_errs;
	unsigned nbits, frame_no;
{
	uint8_t *sp;
	unsigned nb;

	sp = input_bits;
	for (nb = 0; nb < nbits; nb++) {
		if (*sp > 1) {
			fprintf(stderr, "error in %s frame #%u: data bit > 1\n",
				filename_for_errs, frame_no);
			exit(1);
		}
		sp++;
	}
}