+
−/*
+
− * This program reads a 16-bit PCM recording in raw format (robe by default,
+
− * or LE with -l option) and checks whether or not every sample fits into
+
− * left-justified 13 bits, with the 3 least significant bits of every 16-bit
+
− * sample cleared.
+
− */
+
−
+
−#include <stdio.h>
+
−#include <stdint.h>
+
−#include <stdlib.h>
+
−#include <string.h>
+
−#include <strings.h>
+
−
+
−main(argc, argv)
+
−	char **argv;
+
−{
+
−	int little_endian;
+
−	char *infname;
+
−	FILE *inf;
+
−	unsigned sample_count;
+
−	uint8_t inb[2];
+
−	uint16_t ins, lowbits;
+
−	int cc;
+
−
+
−	if (argc == 2 && argv[1][0] != '-') {
+
−		little_endian = 0;
+
−		infname = argv[1];
+
−	} else if (argc == 3 && !strcmp(argv[1], "-l")) {
+
−		little_endian = 1;
+
−		infname = argv[2];
+
−	} else {
+
−		fprintf(stderr, "usage: %s [-l] input.pcm16\n", argv[0]);
+
−		exit(1);
+
−	}
+
−	inf = fopen(infname, "r");
+
−	if (!inf) {
+
−		perror(infname);
+
−		exit(1);
+
−	}
+
−	for (sample_count = 0; ; sample_count++) {
+
−		cc = fread(inb, 1, 2, inf);
+
−		if (cc <= 0)
+
−			break;
+
−		if (cc & 1) {
+
−			fprintf(stderr, "error: %s has odd number of bytes\n",
+
−				infname);
+
−			exit(1);
+
−		}
+
−		if (little_endian)
+
−			ins = ((uint16_t) inb[1] << 8) | ((uint16_t) inb[0]);
+
−		else
+
−			ins = ((uint16_t) inb[0] << 8) | ((uint16_t) inb[1]);
+
−		lowbits = ins & 7;
+
−		if (lowbits) {
+
−			fprintf(stderr,
+
−			"check13 fail: %s sample #%u low 3 bits are %u\n",
+
−				infname, sample_count, lowbits);
+
−			exit(1);
+
−		}
+
−	}
+
−	exit(0);
+
−}