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WIP: burst_process: Initial Fax (FA) frame support 

Change-Id: Id4e198a79a56a7a100a84af9dc334b48242f6cfd
This commit is contained in:
Harald Welte 2023-03-19 14:37:18 +01:00
parent 079cbcc626
commit 56e611e95e
2 changed files with 67 additions and 1 deletions
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68
src/host/layer23/src/misc/burst_process.c
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@ -5,14 +5,17 @@
#include <errno.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <arpa/inet.h>
#include <osmocom/core/bits.h>
#include <osmocom/core/conv.h>
#include <osmocom/core/gsmtap.h>
#include <osmocom/core/gsmtap_util.h>
#include <osmocom/isdn/v110.h>
#include <osmocom/gsm/gsm_utils.h>
#include <osmocom/gsm/rsl.h>
#include <osmocom/gsm/gsm0503.h>
#include <osmocom/gsm/gsm44021.h>
#include <l1ctl_proto.h>
#include "rlp.h"
@ -139,6 +142,59 @@ static void handle_rlp_frame(uint32_t fn, uint16_t band_arfcn, uint8_t ts, int8_
}
}
struct fa_state {
ubit_t v110_d[48*4];
uint8_t v110_frame_nr;
};
static const uint8_t fax_sync[8] = { 0x3E, 0x37, 0x50, 0x96, 0xC1, 0xC8, 0xAF, 0x69 };
/* called by TRAU/FA synchronizer for every received FA frame */
static void fa_frame_cb(const ubit_t *bits, unsigned int num_bits)
{
uint8_t packed[8];
OSMO_ASSERT(num_bits == 64);
osmo_ubit2pbit(packed, bits, num_bits);
if (!memcmp(packed, fax_sync, sizeof(packed))) {
printf("\t\tFA: SYNC\n");
} else if (packed[0] /* == packed[2] == packed[4] == packed[6] */ == 0x11) {
printf("\t\tFA: BCS-REC: 0x%02x\n", packed[1]);
} else if (packed[0] /* == packed[2] == packed[4] == packed[6] */ == 0x33) {
printf("\t\tFA: MSG-REC: 0x%02x\n", packed[1]);
} else if (packed[0] /* == packed[2] == packed[4] == packed[6] */ == 0x44) {
printf("\t\tFA: MSG-TRA: 0x%02x\n", packed[1]);
} else {
printf("\t\tFA: %s\n", osmo_hexdump(packed, sizeof(packed)));
//printf("\t\t%s\n", osmo_ubit_dump(bits, num_bits));
}
}
/* called for every (decoded) V.110 frame received over radio link */
static void handle_v110_frame(uint32_t fn, uint16_t band_arfcn, uint8_t ts, int8_t signal_dbm, int8_t snr, const struct osmo_v110_decoded_frame *fr)
{
static struct fa_state fst_ul, fst_dl;
struct fa_state *fst;
if (band_arfcn & ARFCN_UPLINK)
fst = &fst_ul;
else
fst = &fst_dl;
//printf("\t%s\n", osmo_ubit_dump(fr->d_bits, sizeof(fr->d_bits)));
/* FIXME: establish sync with sync frames */
memcpy(fst->v110_d + (fst->v110_frame_nr * 48), fr->d_bits, 48);
if (fst->v110_frame_nr == 4 - 1) {
fa_frame_cb(fst->v110_d + 0, 64);
fa_frame_cb(fst->v110_d + 64, 64);
fa_frame_cb(fst->v110_d + 128, 64);
}
fst->v110_frame_nr = (fst->v110_frame_nr + 1) % 4;
}
struct burst_state {
sbit_t iB[22*114];
uint8_t burst22_nr;
@ -183,9 +239,19 @@ static void process_one_unmapped_burst(uint32_t fn, uint16_t band_arfcn, uint8_t
bst->burst4_nr = 0;
osmo_conv_decode(&gsm0503_tch_f96, cB, decoded);
//printf("\tdec_bin: %s\n", osmo_ubit_dump(decoded, 240));
#if 0
/* non-transparent CSD (RLP) processing */
osmo_ubit2pbit_ext(dec_bytes, 0, decoded, 0, 240, 1);
//printf("\tdec_hex: %s\n", osmo_hexdump(dec_bytes, sizeof(dec_bytes)));
handle_rlp_frame(fn, band_arfcn, ts, signal_dbm, snr, dec_bytes, sizeof(dec_bytes));
#else
/* transparent CSD / FAX processing */
for (int i = 0; i < 4; i++) {
struct osmo_v110_decoded_frame fr;
osmo_csd_12k_6k_decode_frame(&fr, decoded + i*60, 60);
handle_v110_frame(fn, band_arfcn, ts, signal_dbm, snr, &fr);
}
#endif
/* move remainder of iB towards head */
memmove(&bst->iB[0], &bst->iB[4*114], 18*114);
@ -239,7 +305,7 @@ static int read_and_process_one_burst(int burst_fd)
dir = 'U';
else
dir = 'D';
#if 0
#if 1
/* skip uplink for now */
if (dir == 'D')
return 0;

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src/host/layer23/src/misc/bursts_csd_9600_t_fax_mo_gplv2.dat Normal file
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