output is an unpacked array of bits of maximum size max_out. Note
unpacked arrays are a more suitable form for modulator input.
- longcode == 1 varicode table that covers entire ASCII char set
- longcode == 0 is the short, more efficient table, which covers a subset of the ASCII char set. Unknown
- chars are replaced with spaces. This mode works with two bits at a time.
+ Code 1 covers the entire ASCII char set.
*/
-int varicode_encode(short varicode_out[], char ascii_in[], int max_out, int n_in, int long_code) {
- int n_out, index, n_zeros, v_len, i;
+int varicode_encode1(short varicode_out[], char ascii_in[], int max_out, int n_in) {
+ int n_out, index, n_zeros, v_len;
unsigned short byte1, byte2, packed;
n_out = 0;
while(n_in && (n_out < max_out)) {
- if (long_code) {
- assert((unsigned int)(*ascii_in) < 128);
+ assert((unsigned int)(*ascii_in) < 128);
- index = 2*(unsigned int)(*ascii_in);
- byte1 = long_varicode_table[index];
- byte2 = long_varicode_table[index+1];
- packed = (byte1 << 8) + byte2;
+ index = 2*(unsigned int)(*ascii_in);
+ byte1 = varicode_table1[index];
+ byte2 = varicode_table1[index+1];
+ packed = (byte1 << 8) + byte2;
+
+ //printf("n_in: %d ascii_in: %c index: %d packed 0x%x\n", n_in, *ascii_in, index, packed);
+ ascii_in++;
+
+ n_zeros = 0;
+ v_len = 0;
+ while ((n_zeros < 2) && (n_out < max_out) && (v_len <= VARICODE_MAX_BITS)) {
+ if (packed & 0x8000) {
+ *varicode_out = 1;
+ n_zeros = 0;
+ }
+ else {
+ *varicode_out = 0;
+ n_zeros++;
+ }
+ //printf("packed: 0x%x *varicode_out: %d n_zeros: %d v_len: %d\n", packed, *varicode_out, n_zeros,v_len );
+ packed <<= 1;
+ varicode_out++;
+ n_out++;
+ v_len++;
}
- else {
+ assert(v_len <= VARICODE_MAX_BITS);
+
+ n_in--;
+ }
+
+ return n_out;
+}
+
+
+/*
+ Code 2 covers a subset, but is more efficient that Code 1 (282
+ compared to 1315 bits on unittest) Unsupported characters are
+ replaced by spaces. We encode/decode two bits at a time.
+*/
- packed = short_varicode_table[0]; // default to space if char not found
+int varicode_encode2(short varicode_out[], char ascii_in[], int max_out, int n_in) {
+ int n_out, n_zeros, v_len, i;
+ unsigned short packed;
+
+ n_out = 0;
+
+ while(n_in && (n_out < max_out)) {
+
+ packed = varicode_table2[0]; // default to space if char not found
- // see if our character exists
- for(i=0; i<sizeof(short_varicode_table); i+=2) {
- if (short_varicode_table[i] == *ascii_in)
- packed = (unsigned short)short_varicode_table[i+1] << 8;
- }
+ // see if our character exists
+ for(i=0; i<sizeof(varicode_table2); i+=2) {
+ if (varicode_table2[i] == *ascii_in)
+ packed = (unsigned short)varicode_table2[i+1] << 8;
}
//printf("n_in: %d ascii_in: %c index: %d packed 0x%x\n", n_in, *ascii_in, index, packed);
n_zeros = 0;
v_len = 0;
while ((n_zeros < 2) && (n_out < max_out) && (v_len <= VARICODE_MAX_BITS)) {
- if (long_code) {
- if (packed & 0x8000) {
- *varicode_out = 1;
- n_zeros = 0;
- }
- else {
- *varicode_out = 0;
- n_zeros++;
- }
- //printf("packed: 0x%x *varicode_out: %d n_zeros: %d v_len: %d\n", packed, *varicode_out, n_zeros,v_len );
- packed <<= 1;
- varicode_out++;
- n_out++;
- v_len++;
- }
- else {
- if (packed & 0x8000)
- varicode_out[0] = 1;
- else
- varicode_out[0] = 0;
+ if (packed & 0x8000)
+ varicode_out[0] = 1;
+ else
+ varicode_out[0] = 0;
- if (packed & 0x4000)
- varicode_out[1] = 1;
- else
- varicode_out[1] = 0;
-
- if (packed & 0xc000)
- n_zeros = 0;
- else
- n_zeros += 2;
-
- //printf("packed: 0x%x *varicode_out: %d n_zeros: %d v_len: %d\n", packed, *varicode_out, n_zeros,v_len );
- packed <<= 2;
- varicode_out +=2;
- n_out += 2;
- v_len += 2;
- }
+ if (packed & 0x4000)
+ varicode_out[1] = 1;
+ else
+ varicode_out[1] = 0;
+ if (packed & 0xc000)
+ n_zeros = 0;
+ else
+ n_zeros += 2;
+
+ //printf("packed: 0x%x *varicode_out: %d n_zeros: %d v_len: %d\n", packed, *varicode_out, n_zeros,v_len );
+ packed <<= 2;
+ varicode_out +=2;
+ n_out += 2;
+ v_len += 2;
}
assert(v_len <= VARICODE_MAX_BITS);
n_in--;
}
+ assert((n_out % 2) == 0); /* outputs two bits at a time */
+
return n_out;
}
-void varicode_decode_init(struct VARICODE_DEC *dec_states)
+
+int varicode_encode(short varicode_out[], char ascii_in[], int max_out, int n_in, int code_num) {
+
+ assert((code_num ==1) || (code_num ==2));
+
+ if (code_num == 1)
+ return varicode_encode1(varicode_out, ascii_in, max_out, n_in);
+ else
+ return varicode_encode2(varicode_out, ascii_in, max_out, n_in);
+}
+
+
+void varicode_decode_init(struct VARICODE_DEC *dec_states, int code_num)
{
+ assert((code_num ==1) || (code_num ==2));
+
dec_states->state = 0;
dec_states->n_zeros = 0;
dec_states->v_len = 0;
dec_states->packed = 0;
+ dec_states->code_num = code_num;
}
-static int decode_one_bit(struct VARICODE_DEC *s, char *single_ascii, short varicode_in1, short varicode_in2, int long_code)
+
+/* Code 1 decode function, accepts one bit at a time */
+
+static int decode_one_bit(struct VARICODE_DEC *s, char *single_ascii, short varicode_in, int long_code)
{
int found, i;
unsigned short byte1, byte2;
// s->state, varicode_in, s->packed, s->n_zeros);
if (s->state == 0) {
- if (long_code) {
- if (!varicode_in1)
- return 0;
- else
- s->state = 1;
- }
- else {
- if (!(varicode_in1 || varicode_in2))
- return 0;
- else
- s->state = 1;
- }
-
+ if (!varicode_in)
+ return 0;
+ else
+ s->state = 1;
}
if (s->state == 1) {
- if (long_code) {
- if (varicode_in1) {
- s->packed |= (0x8000 >> s->v_len);
- s->n_zeros = 0;
- }
- else {
- s->n_zeros++;
- }
- s->v_len++;
+ if (varicode_in) {
+ s->packed |= (0x8000 >> s->v_len);
+ s->n_zeros = 0;
}
else {
- if (varicode_in1)
- s->packed |= (0x8000 >> s->v_len);
- if (varicode_in2)
- s->packed |= (0x4000 >> s->v_len);
- if (varicode_in1 || varicode_in2)
- s->n_zeros = 0;
- else
- s->n_zeros+=2;
-
- s->v_len+=2;
+ s->n_zeros++;
}
-
+ s->v_len++;
found = 0;
/* end of character code */
byte1 = s->packed >> 8;
//printf("looking for byte1 : 0x%x ... ", byte1);
- if (long_code) {
- byte2 = s->packed & 0xff;
-
- for(i=0; i<128; i++) {
- if ((byte1 == long_varicode_table[2*i]) && (byte2 == long_varicode_table[2*i+1])) {
- found = 1;
- *single_ascii = i;
- }
+ byte2 = s->packed & 0xff;
+
+ for(i=0; i<128; i++) {
+ if ((byte1 == varicode_table1[2*i]) && (byte2 == varicode_table1[2*i+1])) {
+ found = 1;
+ *single_ascii = i;
}
}
- else {
- for(i=0; i<sizeof(short_varicode_table); i+=2) {
- //printf("byte1: 0x%x 0x%x\n", byte1, (unsigned char)short_varicode_table[i+1]);
- if (byte1 == (unsigned char)short_varicode_table[i+1]) {
- found = 1;
- *single_ascii = short_varicode_table[i];
- //printf("found: %d i=%d char=%c ", found, i, *single_ascii);
- }
+ }
+ varicode_decode_init(s, s->code_num);
+ }
+
+ /* code can run too long if we have a bit error */
+
+ if (s->v_len > VARICODE_MAX_BITS)
+ varicode_decode_init(s, s->code_num);
+ }
+
+ return found;
+}
+
+
+/* Code 2 decode function, accepts two bits at a time */
+
+static int decode_two_bits(struct VARICODE_DEC *s, char *single_ascii, short varicode_in1, short varicode_in2)
+{
+ int found, i;
+ unsigned short byte1;
+
+ //printf("decode_one_bit : state: %d varicode_in: %d packed: 0x%x n_zeros: %d\n",
+ // s->state, varicode_in, s->packed, s->n_zeros);
+
+ if (s->state == 0) {
+ if (!(varicode_in1 || varicode_in2))
+ return 0;
+ else
+ s->state = 1;
+ }
+
+ if (s->state == 1) {
+ if (varicode_in1)
+ s->packed |= (0x8000 >> s->v_len);
+ if (varicode_in2)
+ s->packed |= (0x4000 >> s->v_len);
+ if (varicode_in1 || varicode_in2)
+ s->n_zeros = 0;
+ else
+ s->n_zeros+=2;
+
+ s->v_len+=2;
+
+ found = 0;
+
+ /* end of character code */
+
+ if (s->n_zeros == 2) {
+ if (s->v_len) {
+ /* run thru table but note with bit errors we might not actually find a match */
+
+ byte1 = s->packed >> 8;
+ //printf("looking for byte1 : 0x%x ... ", byte1);
+ for(i=0; i<sizeof(varicode_table2); i+=2) {
+ //printf("byte1: 0x%x 0x%x\n", byte1, (unsigned char)varicode_table2[i+1]);
+ if (byte1 == (unsigned char)varicode_table2[i+1]) {
+ found = 1;
+ *single_ascii = varicode_table2[i];
+ //printf("found: %d i=%d char=%c ", found, i, *single_ascii);
}
}
- //printf("\n");
}
- varicode_decode_init(s);
+ varicode_decode_init(s, s->code_num);
}
/* code can run too long if we have a bit error */
if (s->v_len > VARICODE_MAX_BITS)
- varicode_decode_init(s);
+ varicode_decode_init(s, s->code_num);
}
return found;
}
-int varicode_decode(struct VARICODE_DEC *dec_states, char ascii_out[], short varicode_in[], int max_out, int n_in, int long_code) {
+
+int varicode_decode1(struct VARICODE_DEC *dec_states, char ascii_out[], short varicode_in[], int max_out, int n_in) {
int output, n_out;
char single_ascii;
//printf("varicode_decode: n_in: %d\n", n_in);
while(n_in && (n_out < max_out)) {
- if (long_code) {
- output = decode_one_bit(dec_states, &single_ascii, varicode_in[0], 0, long_code);
- varicode_in++;
- n_in--;
- }
- else {
- output = decode_one_bit(dec_states, &single_ascii, varicode_in[0], varicode_in[1], long_code);
- varicode_in +=2;
- n_in -= 2;
- }
+ output = decode_one_bit(dec_states, &single_ascii, varicode_in[0], 0);
+ varicode_in++;
+ n_in--;
if (output) {
*ascii_out++ = single_ascii;
}
+int varicode_decode2(struct VARICODE_DEC *dec_states, char ascii_out[], short varicode_in[], int max_out, int n_in) {
+ int output, n_out;
+ char single_ascii;
+
+ //assert((n_in % 2) == 0); /* code always processes two bits at a time */
+ n_out = 0;
+
+ //printf("varicode_decode: n_in: %d\n", n_in);
+
+ while(n_in && (n_out < max_out)) {
+ output = decode_two_bits(dec_states, &single_ascii, varicode_in[0], varicode_in[1]);
+ varicode_in +=2;
+ n_in -= 2;
+
+ if (output) {
+ *ascii_out++ = single_ascii;
+ n_out++;
+ }
+ }
+
+ return n_out;
+}
+
+
+int varicode_decode(struct VARICODE_DEC *dec_states, char ascii_out[], short varicode_in[], int max_out, int n_in) {
+ if (dec_states->code_num == 1)
+ return varicode_decode1(dec_states, ascii_out, varicode_in, max_out, n_in);
+ else
+ return varicode_decode2(dec_states, ascii_out, varicode_in, max_out, n_in);
+}
+
+
#ifdef VARICODE_UNITTEST
-void test_varicode(int long_code) {
+void test_varicode(int code_num) {
char *ascii_in;
short *varicode;
int i, n_varicode_bits_out, n_ascii_chars_out, length, half;
char *ascii_out;
struct VARICODE_DEC dec_states;
- if (long_code) {
+ if (code_num == 1) {
printf("long code:\n");
- length = sizeof(long_varicode_table)/2;
+ length = sizeof(varicode_table1)/2;
}
else {
printf("short code:\n");
- length = sizeof(short_varicode_table)/2;
+ length = sizeof(varicode_table2)/2;
}
//length = 10;
ascii_in = (char*)malloc(length);
// 1. test all Varicode codes -------------------------------------------------------------
- if (long_code) {
+ if (code_num == 1) {
for(i=0; i<length; i++)
ascii_in[i] = (char)i;
}
else {
for(i=0; i<length; i++)
- ascii_in[i] = short_varicode_table[2*i];
+ ascii_in[i] = varicode_table2[2*i];
}
//printf(" ascii_in: %s\n", ascii_in);
- n_varicode_bits_out = varicode_encode(varicode, ascii_in, VARICODE_MAX_BITS*length, length, long_code);
+ n_varicode_bits_out = varicode_encode(varicode, ascii_in, VARICODE_MAX_BITS*length, length, code_num);
printf(" n_varicode_bits_out: %d\n", n_varicode_bits_out);
//for(i=0; i<n_varicode_bits_out; i++) {
// printf("%d \n", varicode[i]);
//}
- // split decode in half to test how it preseves state between calls
+ // split decode in half to test how it preserves state between calls
- varicode_decode_init(&dec_states);
+ varicode_decode_init(&dec_states, code_num);
half = n_varicode_bits_out/2;
- n_ascii_chars_out = varicode_decode(&dec_states, ascii_out, varicode, length, half, long_code);
+ n_ascii_chars_out = varicode_decode(&dec_states, ascii_out, varicode, length, half);
// printf(" n_ascii_chars_out: %d\n", n_ascii_chars_out);
n_ascii_chars_out += varicode_decode(&dec_states, &ascii_out[n_ascii_chars_out],
- &varicode[half], length-n_ascii_chars_out, n_varicode_bits_out - half, long_code);
+ &varicode[half], length-n_ascii_chars_out, n_varicode_bits_out - half);
//printf("n_ascii_chars_out: %d\n", n_ascii_chars_out);
assert(n_ascii_chars_out == length);
sprintf(ascii_in, "CQ CQ CQ, this is VK5DGR");
assert(strlen(ascii_in) < length);
- if (long_code == 0)
+ if (code_num == 2)
for(i=0; i<strlen(ascii_in); i++)
ascii_in[i] = tolower(ascii_in[i]);
for(i=0; i<3; i++) {
- n_varicode_bits_out = varicode_encode(varicode, ascii_in, VARICODE_MAX_BITS*length, strlen(ascii_in), long_code);
- n_ascii_chars_out = varicode_decode(&dec_states, ascii_out, varicode, length, n_varicode_bits_out, long_code);
+ n_varicode_bits_out = varicode_encode(varicode, ascii_in, VARICODE_MAX_BITS*length, strlen(ascii_in), code_num);
+ n_ascii_chars_out = varicode_decode(&dec_states, ascii_out, varicode, length, n_varicode_bits_out);
ascii_out[n_ascii_chars_out] = 0;
printf("ascii_out: %s\n", ascii_out);
printf(" Test 2 Fail\n");
memset(varicode, 0, sizeof(short)*20);
- n_ascii_chars_out = varicode_decode(&dec_states, ascii_out, varicode, length, 20, long_code);
+ n_ascii_chars_out = varicode_decode(&dec_states, ascii_out, varicode, length, 20);
assert(n_ascii_chars_out == 0);
}
}
int main(void) {
- test_varicode(0);
test_varicode(1);
+ test_varicode(2);
return 0;
}
#endif
projects / freetel-svn-tracking.git / commitdiff