diff options
Diffstat (limited to 'gsm-tvoid/src/lib/gsmstack.c')
| -rw-r--r-- | gsm-tvoid/src/lib/gsmstack.c | 85 |
1 files changed, 73 insertions, 12 deletions
diff --git a/gsm-tvoid/src/lib/gsmstack.c b/gsm-tvoid/src/lib/gsmstack.c index 9fc4868..a38ffcb 100644 --- a/gsm-tvoid/src/lib/gsmstack.c +++ b/gsm-tvoid/src/lib/gsmstack.c @@ -10,13 +10,14 @@ #include "gsm_constants.h" #include "interleave.h" #include "sch.h" +#include "cch.h" -INTERLEAVE_CTX ictx; +static void out_gsmdecode(char type, int arfcn, int ts, int fn, char *data, int len); static void diff_decode(char *dst, char *src, int len) { - const unsigned char *end = src + len; + const char *end = src + len; unsigned char last; src += 3; @@ -40,7 +41,9 @@ int GS_new(GS_CTX *ctx) { memset(ctx, 0, sizeof *ctx); - interleave_init(&ictx, 456, 114); + interleave_init(&ctx->interleave_ctx, 456, 114); + ctx->fn = -1; + ctx->bsic = -1; return 0; } @@ -49,26 +52,84 @@ GS_new(GS_CTX *ctx) * 156 bit */ int -GS_process(GS_CTX *ctx, int ts, int type, char *data) +GS_process(GS_CTX *ctx, int ts, int type, char *src) { int fn; int bsic; int ret; char buf[156]; + unsigned char *data; + int len; - diff_decode(buf, data, 156); + if (ts != 0) + return; - switch (type) + diff_decode(buf, src, 156); + + if (type == SCH) { - case SCH: ret = decode_sch(buf, &fn, &bsic); if (ret != 0) - break; - DEBUGF("FN %d, BSIC %d\n", fn, bsic); - break; - case NORMAL: - break; + return 0; + if ((ctx->bsic > 0) && (bsic != ctx->bsic)) + fprintf(stderr, "WARN: BSIC changed.\n"); + //DEBUGF("FN %d, BSIC %d\n", fn, bsic); + ctx->fn = fn; + ctx->bsic = bsic; + /* Reset message concatenator */ + ctx->burst_count = 0; + return 0; + } + + /* If we did not get Frame Number yet then return */ + if (ctx->fn < 0) + return 0; + + ctx->fn++; + if (type == NORMAL) + { + /* Interested in these frame numbers (cch) + * 2-5, 12-15, 22-25, 23-35, 42-45 + * 6-9, 16-19, 26-29, 36-39, 46-49 + */ + /* Copy content data into new array */ + //DEBUGF("burst count %d\n", ctx->burst_count); + memcpy(ctx->burst + (116 * ctx->burst_count), buf + 3, 58); + memcpy(ctx->burst + (116 * ctx->burst_count) + 58, buf + 3 + 58 + 26, 58); + ctx->burst_count++; + /* Return if not enough bursts for a full gsm message */ + if (ctx->burst_count < 4) + return 0; + + ctx->burst_count = 0; + data = decode_cch(ctx, ctx->burst, &len); + if (data == NULL) + return -1; + //DEBUGF("OK TS %d, len %d\n", ts, len); + + out_gsmdecode(0, 0, ts, ctx->fn - 4, data, len); +#if 0 + if (ctx->fn % 51 != 0) && ( (((ctx->fn % 51 + 5) % 10 == 0) || (((ctx->fn % 51) + 1) % 10 ==0) ) ) + ready = 1; +#endif + + return 0; } } +/* + * Output data so that it can be parsed from gsmdeocde. + */ +static void +out_gsmdecode(char type, int arfcn, int ts, int fn, char *data, int len) +{ + char *end = data + len; + + /* FIXME: speed this up by first printing into an array */ + while (data < end) + printf(" %02.2x", (unsigned char)*data++); + printf("\n"); + fflush(stdout); +} + |