--- a/.hgignore	Thu Feb 13 23:43:40 2025 +0000
+++ b/.hgignore	Fri Feb 14 01:34:48 2025 +0000
@@ -86,6 +86,7 @@
 ^hrutil/gsmhr-hex2dec$
 ^hrutil/gsmhr-hex2rpf$
 ^hrutil/gsmhr-rpf2hex$
+^hrutil/gsmhr-tfo-xfrm$
 ^hrutil/tw5b-dump$
 
 ^libgsmhr1/dhf_packed\.c$

--- a/hrutil/Makefile	Thu Feb 13 23:43:40 2025 +0000
+++ b/hrutil/Makefile	Fri Feb 14 01:34:48 2025 +0000
@@ -1,6 +1,6 @@
 PROGS=	gsmhr-cod-craft gsmhr-cod-parse gsmhr-cod2hex gsmhr-dec-craft \
 	gsmhr-dec-parse gsmhr-dec2hex gsmhr-hex2dec gsmhr-hex2rpf gsmhr-rpf2hex\
-	tw5b-dump
+	gsmhr-tfo-xfrm tw5b-dump
 LIBHR1=	../libgsmhr1/libgsmhr1.a
 LIBTEST=../libtest/libtest.a
 LIBS=	${LIBHR1} ${LIBTEST}
@@ -36,6 +36,9 @@
 gsmhr-rpf2hex:	rpf2hex.o ${LIBHR1}
 	${CC} ${CFLAGS} -o $@ $^
 
+gsmhr-tfo-xfrm:	tfo-xfrm.o tw5b-out-cod.o ${LIBS}
+	${CC} ${CFLAGS} -o $@ $^
+
 tw5b-dump:	print-frame.o tw5b-dump.o ${LIBS}
 	${CC} ${CFLAGS} -o $@ $^
 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hrutil/tfo-xfrm.c	Fri Feb 14 01:34:48 2025 +0000
@@ -0,0 +1,87 @@
+/*
+ * This program exercises our ThemWi implementation of TFO transform for
+ * GSM-HR.  It reads a stream of radio leg A Rx frames from a TW-TS-005 Annex B
+ * hex file and writes the "pristine" stream intended for radio leg B Tx
+ * into another TW-TS-005 Annex B hex file.  DTXd can be enabled or disabled;
+ * the output can be in either TS 101 318 or RFC 5993 format.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include "../libgsmhr1/tw_gsmhr.h"
+#include "../libtest/tw5reader.h"
+
+main(argc, argv)
+	char **argv;
+{
+	char *infname, *outfname;
+	FILE *inf, *outf;
+	unsigned lineno;
+	struct gsmhr_rxfe_state *state;
+	uint8_t frame_in[TWTS005_MAX_FRAME];
+	unsigned frame_in_len;
+	int16_t prm_in[GSMHR_NUM_PARAMS_DEC], prm_out[GSMHR_NUM_PARAMS_ENC];
+	int opt, rc, dtxd = 0, emit_5993 = 0;
+	extern int optind;
+
+	while ((opt = getopt(argc, argv, "dx")) != EOF) {
+		switch (opt) {
+		case 'd':
+			dtxd = 1;
+			continue;
+		case 'x':
+			emit_5993 = 1;
+			continue;
+		default:
+		usage:
+			fprintf(stderr,
+				"usage: %s [-d] [-x] input.hex output.hex\n",
+				argv[0]);
+			exit(1);
+		}
+	}
+	if (argc != optind + 2)
+		goto usage;
+	infname = argv[optind];
+	outfname = argv[optind+1];
+
+	inf = fopen(infname, "r");
+	if (!inf) {
+		perror(infname);
+		exit(1);
+	}
+	lineno = 0;
+	outf = fopen(outfname, "w");
+	if (!outf) {
+		perror(outfname);
+		exit(1);
+	}
+	state = gsmhr_rxfe_create();
+	if (!state) {
+		fprintf(stderr, "gsmhr_rxfe_create() failed!\n");
+		exit(1);
+	}
+	for (;;) {
+		rc = twts005_read_frame(inf, &lineno, frame_in, &frame_in_len);
+		if (rc < 0) {
+			fprintf(stderr, "%s line %u: not valid TW-TS-005\n",
+				argv[1], lineno);
+			exit(1);
+		}
+		if (!rc)
+			break;
+		rc = gsmhr_rtp_in_direct(frame_in, frame_in_len, prm_in);
+		if (rc < 0) {
+			fprintf(stderr,
+				"%s line %u: not a valid GSM-HR frame\n",
+				infname, lineno);
+			exit(1);
+		}
+		gsmhr_tfo_xfrm(state, dtxd, prm_in, prm_out);
+		emit_cod_to_tw5b(outf, prm_out, emit_5993);
+	}
+	fclose(outf);
+	exit(0);
+}