--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/miscutil/pcm16-check13.c	Sun Apr 23 03:36:25 2023 +0000
@@ -0,0 +1,62 @@
+/*
+ * 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);
+}