altos: improve FEC apis to reduce data copying

Integrate interleaving and whitening into encode and decode steps.
Add CRC checking function for receive.

Make ao_fec_test program round-trip the data and verify correctness.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 0 insertions, 192 deletions

diff --git a/src/test/ao_fec_tx_test.c b/src/test/ao_fec_tx_test.c
deleted file mode 100644
index 1b1fd56d..00000000
--- a/src/test/ao_fec_tx_test.c
+++ /dev/null
@@ -1,192 +0,0 @@
-/*
- * Copyright © 2012 Keith Packard <keithp@keithp.com>
- *
- * 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; version 2 of the License.
- *
- * 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, write to the Free Software Foundation, Inc.,
- * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
- */
-
-#include <ao_fec.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include <math.h>
-
-#ifndef RANDOM_MAX
-#define RANDOM_MAX 0x7fffffff
-#endif
-
-static double
-rand_real(void) {
-	return (double) random() / (double) RANDOM_MAX;
-}
-
-static double
-gaussian_random(double mean, double dev)
-{
-	static int	save_x_valid = 0;
-	static double	save_x;
-	double		x;
-
-	if (save_x_valid)
-	{
-		x = save_x;
-		save_x_valid = 0;
-	}
-	else
-	{
-		double    w;
-		double    normal_x1, normal_x2;
-
-		do {
-			normal_x1 = 2 * rand_real () - 1;
-			normal_x2 = 2 * rand_real () - 1;
-			w = normal_x1*normal_x1 + normal_x2*normal_x2;
-		} while (w >= 1 || w < 1E-30);
-
-		w = sqrt(log(w)*(-2./w));
-
-		/*
-		 * normal_x1 and normal_x2 are independent normally
-		 * distributed variates
-		 */
-
-		x = normal_x1 * w;
-		/* save normal_x2 for next call */
-		save_x = normal_x2 * w;
-		save_x_valid = 1;
-	}
-	return x * dev + mean;
-}
-
-#define PREPARE_LEN(input_len)		((input_len) + AO_FEC_PREPARE_EXTRA)
-#define ENCODE_LEN(input_len)		(PREPARE_LEN(input_len) * 2)
-#define INTERLEAVE_LEN(input_len)	ENCODE_LEN(input_len)
-
-static int
-ao_encode(uint8_t *input, int input_len, uint8_t *output)
-{
-	uint8_t		prepare[PREPARE_LEN(input_len)];
-	uint8_t		encode[ENCODE_LEN(input_len)];
-	uint8_t		prepare_len;
-	uint8_t		encode_len;
-	uint8_t		interleave_len;
-
-	ao_fec_dump_bytes(input, input_len, "Input");
-
-	prepare_len = ao_fec_prepare(input, input_len, prepare);
-
-	ao_fec_dump_bytes(prepare, prepare_len, "Prepare");
-	
-	encode_len = ao_fec_encode(prepare, prepare_len, encode);
-
-	ao_fec_dump_bytes(encode, encode_len, "Encode");
-	
-	interleave_len = ao_fec_interleave(encode, encode_len, output);
-
-	ao_fec_dump_bytes(output, interleave_len, "Interleave");
-
-	return interleave_len;
-}
-
-#define RADIO_LEN(input_len)	(INTERLEAVE_LEN(input_len) * 8)
-
-static int
-ao_radio(uint8_t *bits, int bits_len, uint8_t *bytes)
-{
-	uint8_t	b, *bytes_orig = bytes;
-	uint8_t	interleave[bits_len];
-	int	i, bit;
-
-	ao_fec_interleave(bits, bits_len, interleave);
-
-	ao_fec_dump_bytes(interleave, bits_len, "De-interleave");
-
-	for (i = 0; i < bits_len; i++) {
-		b = interleave[i];
-		for (bit = 7; bit >= 0; bit--)
-			*bytes++ = ((b >> bit) & 1) * 0xff;
-	}
-
-	ao_fec_dump_bytes(bytes_orig, bits_len * 8, "Bytes");
-
-	return bits_len * 8;
-}
-
-static int
-ao_fuzz (uint8_t *in, int in_len, uint8_t *out, double dev)
-{
-	int	i;
-	int	errors = 0;
-	
-	for (i = 0; i < in_len; i++) {
-		double	error = gaussian_random(0, dev);
-		uint8_t	byte = in[i];
-
-		if (error > 0) {
-			if (error > 0xff)
-				error = 0xff;
-			if (error >= 0x80)
-				errors++;
-			if (byte < 0x80)
-				byte += error;
-			else
-				byte -= error;
-		}
-		out[i] = byte;
-	}
-
-	printf ("Introduced %d errors\n", errors);
-	ao_fec_dump_bytes(out, in_len, "Fuzz");
-	return in_len;
-}
-
-static int
-ao_decode(uint8_t *bytes, int bytes_len, uint8_t *bits)
-{
-	int	bits_len;
-
-	bits_len = ao_fec_decode(bytes, bytes_len, bits);
-
-	ao_fec_dump_bytes(bits, bits_len, "Decode");
-	return bits_len;
-}
-
-int
-main(int argc, char **argv)
-{
-	uint8_t		original[4] = { 3, 1, 2, 3 };
-	uint8_t		encode[INTERLEAVE_LEN(sizeof(original))];
-	int		encode_len;
-
-	uint8_t		transmit[RADIO_LEN(sizeof(original))];
-	int		transmit_len;
-
-	uint8_t		receive[RADIO_LEN(sizeof(original))];
-	int		receive_len;
-
-	uint8_t		decode[INTERLEAVE_LEN(sizeof(original))];
-	int		decode_len;
-
-	encode_len = ao_encode(original, sizeof(original), encode);
-
-	transmit_len = ao_radio(encode, encode_len, transmit);
-
-	/* apply gaussian noise to test viterbi code against errors */
-	receive_len = ao_fuzz(transmit, transmit_len, receive, 0x70);
-
-	decode_len = ao_decode(receive, receive_len, decode);
-
-	return decode_len >= sizeof(original);
-}
-
-