contrib: Add BER testing tool

This implements RTP based GSM BER testing for osmo-bts, implementing
ideas described in https://osmocom.org/projects/osmobts/wiki/BER_Testing

In short: The command transmits a PRBS sequence encapsulated in RTP
frames, which are sent to the BTS, which transmits that data in the
(unimpaired) downlink.  The mobile station receives the data and is
instructed to loop it back in the (possibly impaired) uplink.  The BTS
receives that uplink, puts in in RTP frames which end up being received
back by this very tool.  By correlating the received RTP with the PRBS
sequence, this tool can compute the BER (Bit Error Rate) of the
(possibly impaired) uplink.  Doing this with different RF channel model
simulators in the uplink allows to establish BER at different levels and
channel conditions.

Original code by Sylvain Munaut extended with some comments and Automake
integration by Harald Welte.

Change-Id: I1cffa0ae959e29ec61775b13185fd1057ed7485a

7 files changed, 690 insertions, 1 deletions

diff --git a/.gitignore b/.gitignore
index c33b83cb..72897c57 100644
--- a/.gitignore
+++ b/.gitignore
@@ -105,3 +105,6 @@ doc/manuals/common
 doc/manuals/build
 
 contrib/osmo-bts.spec
+contrib/ber/codec_bit_class.h
+contrib/ber/rtp_ber
+contrib/ber/rtp_gen_map
diff --git a/configure.ac b/configure.ac
index 0e797922..82074d46 100644
--- a/configure.ac
+++ b/configure.ac
@@ -449,6 +449,7 @@ AC_OUTPUT(
     doc/examples/Makefile
     doc/manuals/Makefile
     contrib/Makefile
+    contrib/ber/Makefile
     contrib/systemd/Makefile
     contrib/osmo-bts.spec
     Makefile)
diff --git a/contrib/Makefile.am b/contrib/Makefile.am
index 3439c97b..5594199b 100644
--- a/contrib/Makefile.am
+++ b/contrib/Makefile.am
@@ -1 +1 @@
-SUBDIRS = systemd
+SUBDIRS = systemd ber
diff --git a/contrib/ber/Makefile.am b/contrib/ber/Makefile.am
new file mode 100644
index 00000000..e0273786
--- /dev/null
+++ b/contrib/ber/Makefile.am
@@ -0,0 +1,31 @@
+AM_CPPFLAGS = \
+	$(all_includes) \
+	-I$(top_srcdir)/include \
+	-I$(top_builddir)/include \
+	-I$(builddir) \
+	$(NULL)
+
+AM_CFLAGS = \
+	-Wall \
+	$(LIBOSMOCORE_CFLAGS) \
+	$(LIBOSMOTRAU_CFLAGS) \
+	$(LIBOSMOCODEC_CFLAGS) \
+	$(NULL)
+
+LDADD = \
+	$(LIBOSMOCORE_LIBS) \
+	$(LIBOSMOTRAU_LIBS) \
+	$(LIBOSMOCODEC_LIBS) \
+	$(NULL)
+
+noinst_PROGRAMS = rtp_ber rtp_gen_map
+
+BUILT_SOURCES = codec_bit_class.h
+DISTCLEANFILES = codec_bit_class.h
+
+codec_bit_class.h: rtp_gen_map
+	$(AM_V_GEN)./$< > $@
+
+rtp_ber_SOURCES = rtp_ber.c codec_bit_class.h
+
+rtp_gen_map_SOURCES = rtp_gen_map.c
diff --git a/contrib/ber/README b/contrib/ber/README
new file mode 100644
index 00000000..07c4a785
--- /dev/null
+++ b/contrib/ber/README
@@ -0,0 +1,26 @@
+BER testing tool
+----------------
+
+* Check all configs (MSC/BSC/BTS) for proper codec support
+  - FR enabled
+  - EFR enabled
+  - AMR 12.2 enabled (and all other modes disabled !)
+  - Use `amr-payload octet-aligned` in BSC config
+
+* Check BTS config
+  - Disable jitter buffer : `bts N / rtp jitter-buffer 0`
+
+* Check BSC config
+  - Disable radio timeout : `network / bts n / radio-link-timeout infinite`
+
+* Start BER testing tool
+  - `./rtp_ber 4000`
+
+* On the MSC CLI, start a silent-call, then request GSM to test loop
+  - `subscriber imsi <XXX> silent-call start tch/f speech-amr`
+  - `subscriber imsi <XXX> ms-test close-loop b`
+
+  Don't forget to terminate the loop and terminate the silent call !
+
+  - `subscriber imsi <XXX> ms-test open-loop`
+  - `subscriber imsi <XXX> silent-call stop`
diff --git a/contrib/ber/rtp_ber.c b/contrib/ber/rtp_ber.c
new file mode 100644
index 00000000..01c1441a
--- /dev/null
+++ b/contrib/ber/rtp_ber.c
@@ -0,0 +1,483 @@
+/* RTP based GSM BER testing for osmo-bts, implementing ideas described in
+ * https://osmocom.org/projects/osmobts/wiki/BER_Testing
+ *
+ * In short: The command transmits a PRBS sequence encapsulated in RTP frames, which are sent
+ * to the BTS, which transmits that data in the (unimpaired) downlink.  The mobile station
+ * receives the data and is instructed to loop it back in the (possibly impaired) uplink.
+ * The BTS receives that uplink, puts in in RTP frames which end up being received back by this
+ * very tool.  By correlating the received RTP with the PRBS sequence, this tool can compute
+ * the BER (Bit Error Rate) of the (possibly impaired) uplink.  Doing this with different
+ * RF channel model simulators in the uplink allows to establish BER at different levels and
+ * channel conditions. */
+
+/* (C) 2019 sysmocom - s.f.m.c. GmbH; Author: Sylvain Munaut
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include <osmocom/codec/codec.h>
+#include <osmocom/core/logging.h>
+#include <osmocom/core/prbs.h>
+#include <osmocom/core/timer.h>
+#include <osmocom/core/utils.h>
+#include <osmocom/trau/osmo_ortp.h>
+
+#include <codec_bit_class.h>
+
+
+struct app_state {
+	struct osmo_rtp_socket *rs;
+
+	enum {
+		WAIT_CONN = 0,	/* Wait for incoming connection */
+		WAIT_LOOP,	/* Wait for a somewhat valid packet to start measuring */
+		RUNNING,	/* Main state */
+	} state;
+
+	int pt;
+
+	int     ref_len;
+	uint8_t ref_bytes[GSM_FR_BYTES];	/* FR is the largest possible one */
+	ubit_t  ref_bits[8*GSM_FR_BYTES];
+
+	struct osmo_timer_list rtp_timer;
+
+	uint16_t rx_last_seq;
+	uint32_t rx_last_ts;
+	uint32_t rx_idx;
+	uint32_t tx_idx;
+
+	const int *err_tbl;	/* Classification table */
+	int err_frames;		/* Number of accumulated frames */
+	int err_cnt[3];		/* Bit error counter */
+	int err_tot[3];		/* Total # bits in that class */
+};
+
+#define FLOW_REG_TX_MAX_ADVANCE		200
+#define FLOW_REG_TX_MIN_ADVANCE		 50
+
+
+const struct log_info log_info;
+
+
+static const uint8_t amr_size_by_ft[] = {
+	[0]	= 12,	/* 4.75 */
+	[1]	= 13,	/* 5.15 */
+	[2]	= 15,	/* 5.9 */
+	[3]	= 17,	/* 6.7 */
+	[4]	= 19,	/* 7.4 */
+	[5]	= 20,	/* 7.95 */
+	[6]	= 26,	/* 10.2 */
+	[7]	= 31,	/* 12.2 */
+	[8]	= 5,	/* SID */
+};
+
+static const char * const amr_rate_by_ft[] = {
+	[0]	= "4.75",
+	[1]	= "5.15",
+	[2]	= "5.9",
+	[3]	= "6.7",
+	[4]	= "7.4",
+	[5]	= "7.95",
+	[6]	= "10.2",
+	[7]	= "12.2",
+	[8]	= "SID",
+};
+
+
+static void
+_gsm_fr_gen_ref(struct app_state *as)
+{
+	struct osmo_prbs_state pn9;
+
+	/* Length */
+	as->ref_len = GSM_FR_BYTES;
+
+	/* Marker */
+	as->ref_bits[0] = 1;
+	as->ref_bits[1] = 1;
+	as->ref_bits[2] = 0;
+	as->ref_bits[3] = 1;
+
+	/* PN */
+	osmo_prbs_state_init(&pn9, &osmo_prbs9);
+	pn9.state = 31;
+	osmo_prbs_get_ubits(&as->ref_bits[4], 260, &pn9);
+
+	/* Convert to bytes */
+	osmo_ubit2pbit_ext(as->ref_bytes, 0, as->ref_bits, 0, 8*GSM_FR_BYTES, 0);
+
+	/* Init error classes */
+	as->err_tot[0] =  50;
+	as->err_tot[1] = 132;
+	as->err_tot[2] =  78;
+	as->err_tbl = gsm_fr_bitclass;
+}
+
+static void
+_gsm_efr_gen_ref(struct app_state *as)
+{
+	struct osmo_prbs_state pn9;
+
+	/* Length */
+	as->ref_len = GSM_EFR_BYTES;
+
+	/* Marker */
+	as->ref_bits[0] = 1;
+	as->ref_bits[1] = 1;
+	as->ref_bits[2] = 0;
+	as->ref_bits[3] = 0;
+
+	/* PN */
+	osmo_prbs_state_init(&pn9, &osmo_prbs9);
+	pn9.state = 31;
+	osmo_prbs_get_ubits(&as->ref_bits[4], 244, &pn9);
+
+	/* Convert to bytes */
+	osmo_ubit2pbit_ext(as->ref_bytes, 0, as->ref_bits, 0, 8*GSM_EFR_BYTES, 0);
+
+	/* Init error classes */
+	as->err_tot[0] =  50;
+	as->err_tot[1] = 125;
+	as->err_tot[2] =  73;
+	as->err_tbl = gsm_efr_bitclass;
+}
+
+static void
+_gsm_amr_gen_ref(struct app_state *as)
+{
+	struct osmo_prbs_state pn9;
+	uint8_t hdr[2];
+
+	/* Length */
+	as->ref_len = 33;
+
+	/* Header */
+	hdr[0] = 0x70;
+	hdr[1] = 0x3c;
+	osmo_pbit2ubit_ext(as->ref_bits, 0, hdr, 0, 16, 0);
+
+	/* PN */
+	osmo_prbs_state_init(&pn9, &osmo_prbs9);
+	pn9.state = 31;
+	osmo_prbs_get_ubits(&as->ref_bits[16], 244, &pn9);
+
+	/* Unused bits */
+	as->ref_bits[260] = 0;
+	as->ref_bits[261] = 0;
+	as->ref_bits[262] = 0;
+	as->ref_bits[263] = 0;
+
+	/* Convert to bytes */
+	osmo_ubit2pbit_ext(as->ref_bytes, 0, as->ref_bits, 0, 264, 0);
+
+	/* Init error classes */
+	as->err_tot[0] =  81;
+	as->err_tot[1] = 163;
+	as->err_tot[2] =  -1;
+	as->err_tbl = gsm_amr_12_2_bitclass;
+}
+
+
+static void
+_gsm_gen_ref(struct app_state *as)
+{
+	switch (as->pt) {
+	case RTP_PT_GSM_FULL:
+		_gsm_fr_gen_ref(as);
+		break;
+	case RTP_PT_GSM_EFR:
+		_gsm_efr_gen_ref(as);
+		break;
+	case RTP_PT_AMR:
+		_gsm_amr_gen_ref(as);
+		break;
+	default:
+		fprintf(stderr, "[!] Unsupported payload type for BER measurement\n");
+	}
+}
+
+static int
+_gsm_ber(struct app_state *as, const uint8_t *payload, unsigned int payload_len)
+{
+	ubit_t rx_bits[8*33];
+	int err[3];	/* Class 1a, 1b, 2 */
+	int ones;
+	int i, j;
+
+	if (payload) {
+		/* Process real-payload */
+		osmo_pbit2ubit_ext(rx_bits, 0, payload, 0, 8*payload_len, 0);
+
+		err[0] = err[1] = err[2] = 0;
+		ones = 0;
+
+		for (i = 0; i < 8 * payload_len; i++) {
+			j = as->err_tbl[i];
+			if (j >= 0) {
+				err[j] += rx_bits[i] ^ as->ref_bits[i];
+				ones += rx_bits[i];
+			}
+		}
+
+		if (ones < 32) { // This frames is probably us underrunning Tx, don't use it
+			fprintf(stderr, "[w] Frame ignored as probably TX underrun %d %d\n", as->tx_idx, as->rx_idx);
+			return 1;
+		}
+	} else {
+		/* No payload -> Lost frame completely */
+		err[0] = as->err_tot[0] / 2;
+		err[1] = as->err_tot[1] / 2;
+		err[2] = as->err_tot[2] / 2;
+	}
+
+	if (as->state == RUNNING) {
+		/* Update records */
+		if (err[0] != 0) {
+			/* Class 1a bits bad -> Frame error */
+			as->err_cnt[0]++;
+		}
+
+		as->err_cnt[1] += err[1];	/* Class 1b */
+		as->err_cnt[2] += err[2];	/* class 2  */
+
+		as->err_frames++;
+
+		/* Enough for a read-out ? */
+		if (as->err_frames == 200) {
+			printf("FBER: %4.2f    C1b RBER: %5.3f    C2 RBER: %5.3f\n",
+				100.0f * as->err_cnt[0] / as->err_frames,
+				100.0f * as->err_cnt[1] / (as->err_tot[1] * as->err_frames),
+				100.0f * as->err_cnt[2] / (as->err_tot[2] * as->err_frames)
+			);
+			memset(as->err_cnt, 0, sizeof(as->err_cnt));
+			as->err_frames = 0;
+		}
+	}
+
+	return err[0] != 0;
+}
+
+static int
+_rtp_check_payload_type(const uint8_t *payload, unsigned int payload_len)
+{
+	uint8_t ft;
+	int pt = -1;
+
+	switch (payload_len) {
+	case GSM_FR_BYTES: /* FR  or AMR 12.2k */
+		/* Check for AMR */
+		ft = (payload[1] >> 3) & 0xf;
+		if (ft == 7)
+			pt = RTP_PT_AMR;
+
+		/* Check for FR */
+		else if ((payload[0] & 0xF0) == 0xD0)
+			pt = RTP_PT_GSM_FULL;
+
+		/* None of the above */
+		else
+			fprintf(stderr, "[!] FR without 0xD0 signature or AMR with unknwon Frame Type ?!?\n");
+
+		break;
+	case GSM_EFR_BYTES: /* EFR */
+		if ((payload[0] & 0xF0) != 0xC0)
+			fprintf(stderr, "[!] EFR without 0xC0 signature ?!?\n");
+		pt = RTP_PT_GSM_EFR;
+		break;
+	case GSM_HR_BYTES: /* HR */
+		pt = RTP_PT_GSM_HALF;
+		break;
+	default: /* AMR */
+		{
+			uint8_t cmr, cmi, sti;
+			cmr = payload[0] >> 4;
+			ft = (payload[1] >> 3) & 0xf;
+
+			if (payload_len != amr_size_by_ft[ft]+2)
+				fprintf(stderr, "AMR FT %u(%s) but size %u\n",
+					ft, amr_rate_by_ft[ft], payload_len);
+
+			switch (ft) {
+			case 0: case 1: case 2: case 3:
+			case 4: case 5: case 6: case 7:
+				cmi = ft;
+				printf("AMR SPEECH with FT/CMI %u(%s), "
+					"CMR %u\n",
+					cmi, amr_rate_by_ft[cmi],
+					cmr);
+				break;
+			case 8: /* SID */
+				cmi = (payload[2+4] >> 1) & 0x7;
+				sti = payload[2+4] & 0x10;
+				printf("AMR SID %s with CMI %u(%s), CMR %u(%s)\n",
+					sti ? "UPDATE" : "FIRST",
+					cmi, amr_rate_by_ft[cmi],
+					cmr, amr_rate_by_ft[cmr]);
+				break;
+			}
+		}
+		break;
+	}
+
+	return pt;
+}
+
+static void
+rtp_timer_cb(void *priv)
+{
+	struct app_state *as = (struct app_state *)priv;
+
+	/* Send at least one frame if we're not too far ahead */
+	if (as->tx_idx < (as->rx_idx + FLOW_REG_TX_MAX_ADVANCE)) {
+		osmo_rtp_send_frame(as->rs, as->ref_bytes, as->ref_len, GSM_RTP_DURATION);
+		as->tx_idx++;
+	} else {
+		fprintf(stderr, "Skipped\n");
+	}
+
+	/* Then maybe a second one to try and catch up to RX */
+	if (as->tx_idx < (as->rx_idx + FLOW_REG_TX_MIN_ADVANCE)) {
+		osmo_rtp_send_frame(as->rs, as->ref_bytes, as->ref_len, GSM_RTP_DURATION);
+		as->tx_idx++;
+	}
+
+	/* Re-schedule */
+	osmo_timer_schedule(&as->rtp_timer, 0, 20000);
+}
+
+static int
+rtp_seq_num_diff(uint16_t new, uint16_t old)
+{
+	int d = (int)new - (int)old;
+	while (d > 49152)
+		d -= 65536;
+	while (d < -49152)
+		d += 65536;
+	return d;
+}
+
+static void
+rtp_rx_cb(struct osmo_rtp_socket *rs,
+	const uint8_t *payload, unsigned int payload_len,
+	uint16_t seq_number, uint32_t timestamp, bool marker)
+{
+	struct app_state *as = (struct app_state *)rs->priv;
+	int pt, rc, d;
+
+//	printf("Rx(%u, %d, %d, %d): %s\n", payload_len, seq_number, timestamp, marker, osmo_hexdump(payload, payload_len));
+
+	/* Identify payload */
+	pt = _rtp_check_payload_type(payload, payload_len);
+
+	/* First packet ? */
+	if (as->state == WAIT_CONN) {
+		/* Setup for this payload type */
+		as->pt = pt;
+		osmo_rtp_socket_set_pt(as->rs, pt);
+		_gsm_gen_ref(as);
+
+		/* Timer every 20 ms */
+		osmo_timer_setup(&as->rtp_timer, rtp_timer_cb, as);
+		osmo_timer_add(&as->rtp_timer);
+		osmo_timer_schedule(&as->rtp_timer, 0, 20000);
+
+		/* Init our time tracking */
+		as->rx_last_seq = seq_number;
+		as->rx_last_ts  = timestamp;
+
+		/* Now we wait for a loop */
+		as->state = WAIT_LOOP;
+	}
+
+	/* RX sequence & timstamp tracking */
+	if (rtp_seq_num_diff(seq_number, as->rx_last_seq) > 1)
+		fprintf(stderr, "[!] RTP sequence number discontinuity (%d -> %d)\n", as->rx_last_seq, seq_number);
+
+	d = (timestamp - as->rx_last_ts) / GSM_RTP_DURATION;
+
+	as->rx_idx += d;
+	as->rx_last_seq = seq_number;
+	as->rx_last_ts  = timestamp;
+
+	/* Account for missing frames in BER tracking */
+	if (d > 1) {
+		fprintf(stderr, "[!] RTP %d missing frames assumed lost @%d\n", d-1, seq_number);
+		while (--d)
+			_gsm_ber(as, NULL, 0);
+	}
+
+	/* BER analysis */
+	rc = _gsm_ber(as, payload, payload_len);
+
+	if ((as->state == WAIT_LOOP) && (rc == 0))
+		as->state = RUNNING;
+}
+
+
+int main(int argc, char **argv)
+{
+	struct app_state _as, *as = &_as;
+	int rc, port;
+
+	/* Args */
+	if (argc < 2)
+		return -1;
+
+	port = atoi(argv[1]);
+
+	/* App init */
+	memset(as, 0x00, sizeof(struct app_state));
+
+	log_init(&log_info, NULL);
+	osmo_rtp_init(NULL);
+
+	/* Start auto-connect RTP socket */
+	as->rs = osmo_rtp_socket_create(NULL, 0);
+
+	as->rs->priv = as;
+	as->rs->rx_cb = rtp_rx_cb;
+
+		/* Jitter buffer gets in the way, we want the raw traffic */
+	osmo_rtp_socket_set_param(as->rs, OSMO_RTP_P_JIT_ADAP, 0);
+	osmo_rtp_socket_set_param(as->rs, OSMO_RTP_P_JITBUF, 0);
+
+		/* Bind to requested port */
+	fprintf(stderr, "[+] Binding RTP socket on port %u...\n", port);
+	rc = osmo_rtp_socket_bind(as->rs, "0.0.0.0", port);
+	if (rc < 0) {
+		fprintf(stderr, "[!] error binding RTP socket: %d\n", rc);
+		return rc;
+	}
+
+		/* We 'connect' to the first source we hear from */
+	osmo_rtp_socket_autoconnect(as->rs);
+
+	/* Main loop */
+	while (1)
+		osmo_select_main(0);
+
+	return 0;
+}
diff --git a/contrib/ber/rtp_gen_map.c b/contrib/ber/rtp_gen_map.c
new file mode 100644
index 00000000..40b70253
--- /dev/null
+++ b/contrib/ber/rtp_gen_map.c
@@ -0,0 +1,145 @@
+/* utility to generate codec_bit_class.h, a file with structures
+ * describing which [protection] class each bit of a given codec frame belongs to */
+
+/* (C) 2019 sysmocom - s.f.m.c. GmbH; Author: Sylvain Munaut
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#include <stdio.h>
+
+#include <osmocom/codec/codec.h>
+
+
+static int
+gen_table_fr(int *tbl)
+{
+	int i, j;
+
+	tbl[0] = tbl[1] = tbl[2] = tbl[3] = -1;
+
+	for (i = 0; i < 260; i++) {
+		j = 4 + gsm610_bitorder[i];
+		if (i < 50)
+			tbl[j] = 0;	/* Class 1a */
+		else if (i < 182)
+			tbl[j] = 1;	/* Class 1b */
+		else
+			tbl[j] = 2;	/* Class 2 */
+	}
+
+	return GSM_FR_BYTES * 8;
+}
+
+static int
+gen_table_efr(int *tbl)
+{
+	int i, j, k;
+
+	tbl[0] = tbl[1] = tbl[2] = tbl[3] = -1;
+
+	for (i = 0; i < 260; i++) {
+		j = gsm660_bitorder[i];
+
+		if (j < 71)
+			k = j;
+		else if (j < 73)
+			k = 71;
+		else if (j < 123)
+			k = j - 2;
+		else if (j < 125)
+			k = 119;
+		else if (j < 178)
+			k = j - 4;
+		else if (j < 180)
+			k = 172;
+		else if (j < 230)
+			k = j - 6;
+		else if (j < 232)
+			k = 222;
+		else if (j < 252)
+			k = j - 8;
+		else
+			continue;
+
+		if (i < 50)
+			tbl[k] = 0;	/* Class 1a */
+		else if (i < 182)
+			tbl[k] = 1;	/* Class 1b */
+		else
+			tbl[k] = 2;	/* Class 2 */
+	}
+
+	return GSM_EFR_BYTES * 8;
+}
+
+static int
+gen_table_amr_12_2(int *tbl)
+{
+	int i;
+
+	for (i = 0; i < 16; i++)
+		tbl[i] = -1;
+
+	for (i = 0; i < 244; i++)
+		tbl[i+16] = i < 81 ? 0 : 1;
+
+	for (i = 0; i < 4; i++)
+		tbl[i+16+244] = -1;
+
+	return 8 * 33;
+}
+
+
+static void
+print_table(const char  *name, int *tbl, int len)
+{
+	int i;
+
+	printf("static const int %s[] = {\n", name);
+
+	for (i = 0; i < len; i++) {
+		if ((i & 15) == 0)
+			printf("\t");
+
+		printf("%2d", tbl[i]);
+
+		if (((i & 15) == 15) || (i == len-1))
+			printf(",\n");
+		else
+			printf(", ");
+	}
+
+	printf("};\n\n");
+}
+
+
+int main(int argc, char *argv[])
+{
+	int tbl[33*8];
+	int rv;
+
+	rv = gen_table_fr(tbl);
+	print_table("gsm_fr_bitclass", tbl, rv);
+
+	rv = gen_table_efr(tbl);
+	print_table("gsm_efr_bitclass", tbl, rv);
+
+	rv = gen_table_amr_12_2(tbl);
+	print_table("gsm_amr_12_2_bitclass", tbl, rv);
+
+	return 0;
+}