/*
 * The set of AMR test sequences shipped by 3GPP as TS 26.074 includes
 * not only linear PCM (13-bit left-justified) and AMR-encoded files,
 * but also 8-bit PCM sequences in both A-law and mu-law.  However,
 * those PCM8 sequences are shipped in a stupid and inconvenient format:
 * each 8-bit PCM sample is expanded to a 16-bit word, written in LE
 * byte order.  This utility converts a PCM8 test sequence file
 * from this weird format into sane PCM8 format with one byte per sample.
 * For this conversion, it does not matter whether the PCM8 test sequence
 * in question is A-law or mu-law.
 */

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

main(argc, argv)
	char **argv;
{
	FILE *inf, *outf;
	int cdat, cpad;

	if (argc != 3) {
		fprintf(stderr, "usage: %s in-file out-file\n", argv[0]);
		exit(1);
	}
	inf = fopen(argv[1], "r");
	if (!inf) {
		perror(argv[1]);
		exit(1);
	}
	outf = fopen(argv[2], "w");
	if (!outf) {
		perror(argv[2]);
		exit(1);
	}
	for (;;) {
		cdat = getc(inf);
		if (cdat < 0)
			break;
		cpad = getc(inf);
		if (cpad < 0) {
			fprintf(stderr, "error: %s has odd length\n", argv[1]);
			exit(1);
		}
		if (cpad != 0) {
			fprintf(stderr,
				"error: presumed padding byte in %s is not 0\n",
				argv[1]);
			exit(1);
		}
		putc(cdat, outf);
	}
	fclose(outf);
	exit(0);
}