#define DECODE_LEN(input_len) ((input_len) + AO_FEC_PREPARE_EXTRA)
#define EXPAND_LEN(input_len) (ENCODE_LEN(input_len) * 8)
+static uint8_t ao_bit(uint8_t b) {
+ if (b)
+ return 0x00;
+ return 0xff;
+}
+
static int
ao_expand(uint8_t *bits, int bits_len, uint8_t *bytes)
{
for (i = 0; i < bits_len; i++) {
b = bits[i];
for (bit = 7; bit >= 0; bit--)
- *bytes++ = ((b >> bit) & 1) * 0xff;
+ *bytes++ = ao_bit ((b >> bit) & 1);
}
return bits_len * 8;
{
int i;
int errors = 0;
+ int s;
for (i = 0; i < in_len; i++) {
double error = gaussian_random(0, dev);
else
byte -= error;
}
+
+ /* abcd efgh 8
+ * abcd efga 7
+ * abcd efab 6
+ * abcd eabc 5
+ * abcd abcd 4
+ * abca bcab 3
+ * abab abab 2
+ * aaaa aaaa 1
+ */
+
+#define SAVE 8
+#define SAVE_MASK (((1 << SAVE) - 1) << (8 - SAVE))
+
+ byte &= SAVE_MASK;
+ for (s = SAVE; s < 8; s += SAVE)
+ byte |= byte >> s;
+
out[i] = byte;
}
return errors;
static uint8_t real_packet[] = {
- 0x00, 0x40, 0x38, 0xcd, 0x38, 0x3d, 0x34, 0xca, 0x31, 0xc3, 0xc1, 0xc6, 0x35, 0xcc, 0x3a, 0x3c,
+ 0x40, 0x38, 0xcd, 0x38, 0x3d, 0x34, 0xca, 0x31, 0xc3, 0xc1, 0xc6, 0x35, 0xcc, 0x3a, 0x3c,
0x3c, 0x3d, 0x3c, 0x37, 0xc5, 0xc1, 0xc0, 0xc1, 0xc1, 0xc3, 0xc0, 0xc1, 0xc6, 0x38, 0x3b, 0xc6,
0xc0, 0xc6, 0x32, 0xc9, 0xc9, 0x34, 0xcf, 0x35, 0xcf, 0x3a, 0x3b, 0xc6, 0xc7, 0x35, 0xcf, 0x36,
0xce, 0x37, 0xc8, 0xc8, 0x3a, 0x3c, 0xc9, 0xc8, 0x3a, 0x3c, 0xcc, 0x32, 0xcd, 0x32, 0xce, 0x32,
};
-void
+int
ao_real_packet(void)
{
uint8_t decode[64];
- uint8_t decode_len;
- int off;
+ int ok;
- for (off = 0; off < sizeof (real_packet) - 576; off++) {
- decode_len = ao_fec_decode(real_packet+off, 576, decode);
+ ok = ao_fec_decode(real_packet, 576, decode, 34, NULL);
- if (ao_fec_check_crc(decode, 32)) {
- printf ("match at %d\n", off);
+ if (ok && decode[33] == AO_FEC_DECODE_CRC_OK) {
+ printf ("match\n");
- ao_fec_dump_bytes(decode, decode_len, "Decode");
- }
+ ao_fec_dump_bytes(decode, 34, "Decode");
+ } else {
+ printf ("actual packet crc error\n");
+ ok = 0;
}
+ return ok;
}
+#define EXPECT_DECODE_FAIL 0
+#define EXPECT_CRC_MISMATCH 6386
+#define EXPECT_DATA_MISMATCH 0
+#define NOISE_AMOUNT 0x50
+
int
main(int argc, char **argv)
{
int transmit_len;
uint8_t receive[EXPAND_LEN(sizeof(original))];
- int receive_len, receive_errors;
+ int receive_len;
uint8_t decode[DECODE_LEN(sizeof(original))];
- int decode_len;
+ int decode_ok;
int errors = 0;
- int error;
+ int decode_fail = 0;
+ int crc_mismatch = 0;
+ int data_mismatch = 0;
+
+ if (!ao_real_packet())
+ errors++;
- ao_real_packet(); exit(0);
srandom(0);
- for (trial = 0; trial < 10000; trial++) {
+ for (trial = 0; trial < 100000; trial++) {
/* Compute some random data */
original_len = ao_random_data(original, sizeof(original));
transmit_len = ao_expand(encode, encode_len, transmit);
/* Add gaussian noise to the signal */
- receive_errors = ao_fuzz(transmit, transmit_len, receive, 0x30);
+ (void) ao_fuzz(transmit, transmit_len, receive, NOISE_AMOUNT);
receive_len = transmit_len;
/* Decode it */
- decode_len = ao_fec_decode(receive, receive_len, decode);
+ decode_ok = ao_fec_decode(receive, receive_len, decode, original_len + 2, NULL);
/* Check to see if we received the right data */
- error = 0;
- if (decode_len < original_len + 2) {
- printf ("len mis-match\n");
- error++;
- }
+ if (!decode_ok)
+ decode_fail++;
+ else if (decode[original_len +1] != AO_FEC_DECODE_CRC_OK)
+ crc_mismatch++;
+ else if (memcmp(original, decode, original_len) != 0)
+ data_mismatch++;
+ }
- if (!ao_fec_check_crc(decode, original_len)) {
- printf ("crc mis-match\n");
- error++;
- }
- if (memcmp(original, decode, original_len) != 0) {
- printf ("data mis-match\n");
- error++;
- }
- if (error) {
- printf ("Errors: %d\n", receive_errors);
- ao_fec_dump_bytes(original, original_len, "Input");
- ao_fec_dump_bytes(decode, original_len, "Decode");
- errors += error;
- }
+ printf ("%d packets coded\n", trial);
+ printf ("decode_fail %d crc_mismatch %d data_mismatch %d\n",
+ decode_fail, crc_mismatch, data_mismatch);
+ if (decode_fail != EXPECT_DECODE_FAIL) {
+ printf ("expected %d decode failures\n", EXPECT_DECODE_FAIL);
+ errors++;
+ }
+ if (crc_mismatch != EXPECT_CRC_MISMATCH) {
+ printf ("expected %d crc mismatch\n", EXPECT_CRC_MISMATCH);
+ errors++;
+ }
+ if (data_mismatch != EXPECT_DATA_MISMATCH) {
+ printf ("expected %d data mismatch\n", EXPECT_DATA_MISMATCH);
+ errors++;
}
return errors;
}