--- a/.hgignore	Wed Dec 28 09:08:50 2022 +0000
+++ b/.hgignore	Wed Dec 28 10:05:46 2022 +0000
@@ -68,6 +68,7 @@
 ^target-utils/tf-breakin/embed\.c$
 ^target-utils/tf-breakin/mkembed$
 
+^tchtools/fc-efr2tch$
 ^tchtools/fc-fr2tch$
 ^tchtools/fc-gsm2vm$
 ^tchtools/fc-tch2fr$

--- a/tchtools/Makefile	Wed Dec 28 09:08:50 2022 +0000
+++ b/tchtools/Makefile	Wed Dec 28 10:05:46 2022 +0000
@@ -1,6 +1,6 @@
 CC=	gcc
 CFLAGS=	-O2
-PROGS=	fc-fr2tch fc-gsm2vm fc-tch2fr fc-vm2gsmx fc-vm2hex
+PROGS=	fc-efr2tch fc-fr2tch fc-gsm2vm fc-tch2fr fc-vm2gsmx fc-vm2hex
 
 INSTALL_PREFIX=	/opt/freecalypso
 
@@ -8,11 +8,15 @@
 
 all:	${PROGS}
 
+EFR2TCH_OBJS=	fc-efr2tch.o efr2dsp.o
 FR2TCH_OBJS=	fc-fr2tch.o gsm0610.o
 GSM2VM_OBJS=	fc-gsm2vm.o gsm0610.o
 TCH2FR_OBJS=	fc-tch2fr.o gsm0610.o
 VM2GSMX_OBJS=	fc-vm2gsmx.o gsm0610.o
 
+fc-efr2tch:	${EFR2TCH_OBJS}
+	${CC} ${CFLAGS} -o $@ ${EFR2TCH_OBJS}
+
 fc-fr2tch:	${FR2TCH_OBJS}
 	${CC} ${CFLAGS} -o $@ ${FR2TCH_OBJS}
 

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tchtools/efr2dsp.c	Wed Dec 28 10:05:46 2022 +0000
@@ -0,0 +1,75 @@
+/*
+ * The utility function implemented in this module constructs a 33-byte
+ * frame for loading into Calypso DSP TCH UL buffer from a standard
+ * 244-bit EFR codec frame in the RTP encoding format of ETSI TS 101 318.
+ */
+
+#include <sys/types.h>
+#include <string.h>
+#include <strings.h>
+
+static const u_short efr_to_tidsp_table[244] = {
+	 50,  24,  25,  37,  38,  43,  44,  26,  42,  27,  39,  40,
+	 45,  51,  52,  41,  46,  28,  29,  47,  53,  77,  78,  30,
+	 54,  55,  79,  56,  80, 109, 110, 111, 112, 113, 114, 115,
+	180, 181,   0,   1,   2,   3,   4,   5,  20,  31,  32,  16,
+	 73, 105, 157,  81, 118, 138, 165,  82, 119, 139, 166,  83,
+	120, 140, 167,  84, 121, 141, 168,  85, 122, 186, 200, 204,
+	224, 244, 205, 225, 245, 206, 226, 246, 207, 227, 247, 208,
+	228, 248,  17,  61, 101, 153, 161,  12,  13,  22,  35,  48,
+	116,  18,  74, 106, 158,  86, 123, 142, 169,  87, 124, 143,
+	170,  88, 125, 144, 171,  89, 126, 145, 172,  90, 127, 189,
+	201, 209, 229, 249, 210, 230, 250, 211, 231, 251, 212, 232,
+	252, 213, 233, 253,  19,  62, 102, 154, 162,   6,   7,   8,
+	  9,  10,  11,  21,  33,  34,  57,  75, 107, 159,  91, 128,
+	146, 173,  92, 129, 147, 174,  93, 130, 148, 175,  94, 131,
+	149, 176,  95, 132, 192, 202, 214, 234, 254, 215, 235, 255,
+	216, 236, 256, 217, 237, 257, 218, 238, 258,  59,  63, 103,
+	155, 163,  14,  15,  23,  36,  49, 117,  58,  76, 108, 160,
+	 96, 133, 150, 177,  97, 134, 198, 199,  98, 135, 151, 178,
+	 99, 136, 152, 179, 100, 137, 195, 203, 219, 239, 259, 220,
+	240, 260, 221, 241, 261, 222, 242, 262, 223, 243, 263,  60,
+	 64, 104, 156, 164
+};
+
+static int
+msb_get_bit(buf, bn)
+	u_char *buf;
+{
+	int pos_byte = bn >> 3;
+	int pos_bit  = 7 - (bn & 7);
+
+	return (buf[pos_byte] >> pos_bit) & 1;
+}
+
+static void
+msb_set_bit(buf, bn)
+	u_char *buf;
+{
+	int pos_byte = bn >> 3;
+	int pos_bit  = 7 - (bn & 7);
+
+	buf[pos_byte] |= (1 << pos_bit);
+}
+
+void
+efr_std_to_tidsp(inbytes, outbytes)
+	u_char *inbytes, *outbytes;
+{
+	int i;
+
+	bzero(outbytes, 33);
+	for (i = 0; i < 244; i++) {
+		if (msb_get_bit(inbytes, i + 4))
+			msb_set_bit(outbytes, efr_to_tidsp_table[i]);
+	}
+	/* set repetition bits */
+	if (outbytes[23] & 0x20)
+		outbytes[23] |= 0x18;
+	if (outbytes[23] & 0x04)
+		outbytes[23] |= 0x03;
+	if (outbytes[24] & 0x80)
+		outbytes[24] |= 0x60;
+	if (outbytes[24] & 0x10)
+		outbytes[24] |= 0x0C;
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/tchtools/fc-efr2tch.c	Wed Dec 28 10:05:46 2022 +0000
@@ -0,0 +1,59 @@
+/*
+ * This utility converts a GSM EFR speech recording from Themyscira Wireless
+ * gsmx format into hex strings of TCH UL bits, to be fed to the TCH UL play
+ * buffer in the Calypso DSP by way of a suitable FreeCalypso firmware version
+ * and the special tch play command in fc-shell.
+ */
+
+#include <sys/types.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+main(argc, argv)
+	char **argv;
+{
+	FILE *inf, *outf;
+	u_char efr_bytes[31], tidsp_bytes[33];
+	int cc, i, gotsome = 0;
+
+	if (argc != 3) {
+		fprintf(stderr, "usage: %s infile outfile\n", argv[0]);
+		exit(1);
+	}
+	inf = fopen(argv[1], "r");
+	if (!inf) {
+		perror(argv[1]);
+		exit(1);
+	}
+	outf = fopen(argv[2], "w");
+	if (!outf) {
+		perror(argv[2]);
+		exit(1);
+	}
+	for (;;) {
+		cc = fread(efr_bytes, 1, 31, inf);
+		if (cc < 31)
+			break;
+		if ((efr_bytes[0] & 0xF0) != 0xC0) {
+invalid:		fprintf(stderr,
+				"error: %s is not in EFR codec format\n",
+				argv[1]);
+			exit(1);
+		}
+		efr_std_to_tidsp(efr_bytes, tidsp_bytes);
+		for (i = 0; i < 33; i++)
+			fprintf(outf, "%02X", tidsp_bytes[i]);
+		putc('\n', outf);
+		gotsome = 1;
+	}
+	fclose(outf);
+	if (cc) {
+		if (gotsome)
+			fprintf(stderr,
+			"warning: extra non-31 bytes at the end of %s\n",
+				argv[1]);
+		else
+			goto invalid;
+	}
+	exit(0);
+}