Add T4 bit map compression routines
Add bit map encoder and decoder functions: decoder is fully functional
while encoder is good enough for testing - no backtracking to find
the best possible compression is implemented. If somebody is willing to
implement MS side of EDGE than this has to be expanded.
Add corresponding tests.
N. B: the encoding is implemented according to ETSI TS 44.060 which is
slightly different from T4 used for fax according to CCITT G31D (RFC 804).
Ticket: OW#2407
Sponsored-by: On-Waves ehf
Signed-off-by: Max <msuraev@sysmocom.de>
diff --git a/tests/bits/bitcomp_test.c b/tests/bits/bitcomp_test.c
new file mode 100644
index 0000000..f6895cf
--- /dev/null
+++ b/tests/bits/bitcomp_test.c
@@ -0,0 +1,66 @@
+#include <inttypes.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <time.h>
+#include <stdbool.h>
+#include <errno.h>
+
+#include <osmocom/core/utils.h>
+#include <osmocom/core/bits.h>
+#include <osmocom/core/bitcomp.h>
+
+static char lol[1024]; // for pretty-printing
+
+int main(int argc, char **argv)
+{
+ srand(time(NULL));
+
+ struct bitvec bv, out;
+ uint8_t i = 20, test[i], data[i];
+
+ bv.data_len = i;
+ bv.data = test;
+ out.data_len = i;
+ out.data = data;
+ bitvec_zero(&bv);
+ bitvec_zero(&out);
+
+ printf("\nrunning static tests...\n");
+
+ printf("\nTEST1:\n 00110111 01000111 10000001 1111\n");
+ bitvec_zero(&bv);
+ bitvec_set_uint(&bv, 0x374781F, 28); bitvec_to_string_r(&bv, lol); printf("%s", lol);
+
+ printf("\nEncoded:\n%d", osmo_t4_encode(&bv)); bitvec_to_string_r(&bv, lol); printf("%s", lol);
+ printf(" [%d]\nExpected:\n0 11011110 10001000 01110101 01100101 100 [35]\n", bv.cur_bit);
+
+ bitvec_zero(&bv);
+ bitvec_set_uint(&bv, 0xDE887565, 32);
+ bitvec_set_uint(&bv, 4, 3);
+ bitvec_to_string_r(&bv, lol);
+ printf(" %s [%d]\n", lol, bv.cur_bit);
+ int d = osmo_t4_decode(&bv, 0, &out);
+ printf("\nDecoded:\n%d", d);
+ bitvec_to_string_r(&out, lol);
+ printf("%s [%d]\n", lol, out.cur_bit);
+ printf("Expected:\n 00110111 01000111 10000001 1111 \n");
+
+ printf("\nTEST2:\n 11111111 11111111 11111111 11111111 11111111 11111111 11111111 11111111 11111111 11111111 00000000 00\n");
+ bitvec_zero(&bv);
+ bitvec_set_uint(&bv, 0xFFFFFFFF, 32);
+ bitvec_set_uint(&bv, 0xFFFFFFFF, 32);
+ bitvec_set_uint(&bv, 0xFFFFFC00, 26); bitvec_to_string_r(&bv, lol); printf("%s", lol);
+ printf("\nEncoded:\n%d", osmo_t4_encode(&bv)); bitvec_to_string_r(&bv, lol); printf("%s", lol);
+ printf(" [%d]\nExpected:\n1 11011101 01000001 00 [18]\n", bv.cur_bit);
+
+ bitvec_zero(&out);
+ d = osmo_t4_decode(&bv, 1, &out);
+ printf("\nDecoded:\n%d", d);
+ bitvec_to_string_r(&out, lol);
+ printf("%s [%d]\n", lol, out.cur_bit);
+ printf("Expected:\n 11111111 11111111 11111111 11111111 11111111 11111111 11111111 11111111 11111111 11111111 00000000 00\n");
+
+ return 0;
+}