--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/miscutil/gsmx-to-tw5a.c	Thu Sep 19 01:06:58 2024 +0000
@@ -0,0 +1,78 @@
+/*
+ * This program converts FR/EFR speech recordings from gsmx binary format
+ * into more formally standardized TW-TS-005 Annex A format.
+ *
+ * FR and EFR frames are written in basic format (no TEH);
+ * BFI marker records are converted into TW-TS-001 No_Data frames.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include "../libgsmfr2/tw_gsmfr.h"
+#include "../libgsmefr/gsm_efr.h"
+#include "../libtest/binreader.h"
+
+static void
+emit_hex_frame(frame, nbytes)
+	uint8_t *frame;
+	unsigned nbytes;
+{
+	unsigned n;
+
+	for (n = 0; n < nbytes; n++)
+		printf("%02X", frame[n]);
+	putchar('\n');
+}
+
+main(argc, argv)
+	char **argv;
+{
+	FILE *binf, *outf;
+	unsigned frame_index;
+	uint8_t frame[BINFILE_MAX_FRAME];
+	int rc;
+
+	if (argc != 3) {
+		fprintf(stderr, "usage: %s input.gsmx output.hex\n", argv[0]);
+		exit(1);
+	}
+	binf = fopen(argv[1], "r");
+	if (!binf) {
+		perror(argv[1]);
+		exit(1);
+	}
+	if (strcmp(argv[2], "-")) {
+		outf = fopen(argv[2], "w");
+		if (!outf) {
+			perror(argv[2]);
+			exit(1);
+		}
+	} else
+		outf = stdout;
+	for (frame_index = 0; ; frame_index++) {
+		rc = binfile_read_frame(binf, frame);
+		if (rc < 0) {
+			fprintf(stderr,
+				"error: garbage in %s after %u frames\n",
+				argv[1], frame_index);
+			exit(1);
+		}
+		if (!rc)
+			break;
+		switch (frame[0] & 0xF0) {
+		case 0xB0:
+			printf("%02X\n", 0xE6 | frame[1] & 1);
+			break;
+		case 0xC0:
+			emit_hex_frame(frame, EFR_RTP_FRAME_LEN);
+			break;
+		case 0xD0:
+			emit_hex_frame(frame, GSMFR_RTP_FRAME_LEN);
+			break;
+		}
+	}
+	exit(0);
+}