--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/miscutil/tw5a-to-gsmx.c	Thu Sep 19 05:02:45 2024 +0000
@@ -0,0 +1,100 @@
+/*
+ * This program converts FR/EFR speech recordings from TW-TS-005 Annex A
+ * hexadecimal format into our older gsmx binary format.
+ */
+
+#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/tw5reader.h"
+
+main(argc, argv)
+	char **argv;
+{
+	FILE *hexf, *outf;
+	unsigned lineno;
+	uint8_t frame[TWTS005_MAX_FRAME];
+	unsigned frame_len;
+	int rc;
+
+	if (argc != 3) {
+		fprintf(stderr, "usage: %s input.hex output.gsmx\n", argv[0]);
+		exit(1);
+	}
+	hexf = fopen(argv[1], "r");
+	if (!hexf) {
+		perror(argv[1]);
+		exit(1);
+	}
+	lineno = 0;
+	outf = fopen(argv[2], "w");
+	if (!outf) {
+		perror(argv[2]);
+		exit(1);
+	}
+	for (;;) {
+		rc = twts005_read_frame(hexf, &lineno, frame, &frame_len);
+		if (rc < 0) {
+			fprintf(stderr, "%s line %u: not valid TW-TS-005\n",
+				argv[1], lineno);
+			exit(1);
+		}
+		if (!rc)
+			break;
+		switch (frame_len) {
+		case 0:
+			putc(0xBF, outf);
+			putc(0, outf);
+			break;
+		case 1:
+			if ((frame[0] & 0xF6) != 0xE6)
+				goto invalid;
+			putc(0xBF, outf);
+			putc(frame[0] & 1, outf);
+			break;
+		case GSMFR_RTP_FRAME_LEN:
+			if ((frame[0] & 0xF0) != 0xD0)
+				goto invalid;
+			fwrite(frame, 1, GSMFR_RTP_FRAME_LEN, outf);
+			break;
+		case GSMFR_RTP_FRAME_LEN+1:
+			if ((frame[0] & 0xF4) != 0xE0)
+				goto invalid;
+			if ((frame[1] & 0xF0) != 0xD0)
+				goto invalid;
+			if (frame[0] & 0x02) {
+				putc(0xBF, outf);
+				putc(frame[0] & 1, outf);
+			} else
+				fwrite(frame + 1, 1, GSMFR_RTP_FRAME_LEN, outf);
+			break;
+		case EFR_RTP_FRAME_LEN:
+			if ((frame[0] & 0xF0) != 0xC0)
+				goto invalid;
+			fwrite(frame, 1, EFR_RTP_FRAME_LEN, outf);
+			break;
+		case EFR_RTP_FRAME_LEN+1:
+			if ((frame[0] & 0xF4) != 0xE0)
+				goto invalid;
+			if ((frame[1] & 0xF0) != 0xC0)
+				goto invalid;
+			if (frame[0] & 0x02) {
+				putc(0xBF, outf);
+				putc(frame[0] & 1, outf);
+			} else
+				fwrite(frame + 1, 1, EFR_RTP_FRAME_LEN, outf);
+			break;
+		default:
+		invalid:
+			fprintf(stderr,
+				"%s line %u: not a valid FR or EFR frame\n",
+				argv[1], lineno);
+			exit(1);
+		}
+	}
+	exit(0);
+}