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Diffstat (limited to 'src/codec2_fdmdv.h')
| -rw-r--r-- | src/codec2_fdmdv.h | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/src/codec2_fdmdv.h b/src/codec2_fdmdv.h new file mode 100644 index 0000000..b93e13e --- /dev/null +++ b/src/codec2_fdmdv.h @@ -0,0 +1,122 @@ +/*---------------------------------------------------------------------------*\ + + FILE........: codec2_fdmdv.h + AUTHOR......: David Rowe + DATE CREATED: April 14 2012 + + A 1400 bit/s (nominal) Frequency Division Multiplexed Digital Voice + (FDMDV) modem. Used for digital audio over HF SSB. See + README_fdmdv.txt for more information, and fdmdv_mod.c and + fdmdv_demod.c for example usage. + + The name codec2_fdmdv.h is used to make it unique when "make + installed". + + References: + + [1] http://n1su.com/fdmdv/FDMDV_Docs_Rel_1_4b.pdf + +\*---------------------------------------------------------------------------*/ + +/* + Copyright (C) 2012 David Rowe + + All rights reserved. + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU Lesser General Public License version 2.1, as + published by the Free Software Foundation. This program is + distributed in the hope that it will be useful, but WITHOUT ANY + WARRANTY; without even the implied warranty of MERCHANTABILITY or + FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public + License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with this program; if not, see <http://www.gnu.org/licenses/>. +*/ + +#ifndef __FDMDV__ +#define __FDMDV__ + +#include "comp.h" +#include "modem_stats.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* set up the calling convention for DLL function import/export for + WIN32 cross compiling */ + +#ifdef __CODEC2_WIN32__ +#ifdef __CODEC2_BUILDING_DLL__ +#define CODEC2_WIN32SUPPORT __declspec(dllexport) __stdcall +#else +#define CODEC2_WIN32SUPPORT __declspec(dllimport) __stdcall +#endif +#else +#define CODEC2_WIN32SUPPORT +#endif + +#define FDMDV_NC 14 /* default number of data carriers */ +#define FDMDV_NC_MAX 20 /* maximum number of data carriers */ +#define FDMDV_BITS_PER_FRAME 28 /* 20ms frames, for nominal 1400 bit/s */ +#define FDMDV_NOM_SAMPLES_PER_FRAME 160 /* modulator output samples/frame and nominal demod samples/frame */ + /* at 8000 Hz sample rate */ +#define FDMDV_MAX_SAMPLES_PER_FRAME 200 /* max demod samples/frame, use this to allocate storage */ +#define FDMDV_SCALE 825 /* suggested scaling for 16 bit shorts */ +#define FDMDV_FCENTRE 1500 /* Centre frequency, Nc/2 carriers below this, Nc/2 carriers above (Hz) */ + +/* 8 to 18 kHz sample rate conversion */ + +#define FDMDV_OS 2 /* oversampling rate */ +#define FDMDV_OS_TAPS_16K 48 /* number of OS filter taps at 16kHz */ +#define FDMDV_OS_TAPS_8K (FDMDV_OS_TAPS_16K/FDMDV_OS) /* number of OS filter taps at 8kHz */ + +/* 8 to 48 kHz sample rate conversion */ + +#define FDMDV_OS_48 6 /* oversampling rate */ +#define FDMDV_OS_TAPS_48K 48 /* number of OS filter taps at 48kHz */ +#define FDMDV_OS_TAPS_48_8K (FDMDV_OS_TAPS_48K/FDMDV_OS_48) /* number of OS filter taps at 8kHz */ + +/* FDMDV states and stats structures */ + +struct FDMDV; + +struct FDMDV * fdmdv_create(int Nc); +void fdmdv_destroy(struct FDMDV *fdmdv_state); +void fdmdv_use_old_qpsk_mapping(struct FDMDV *fdmdv_state); +int fdmdv_bits_per_frame(struct FDMDV *fdmdv_state); +float fdmdv_get_fsep(struct FDMDV *fdmdv_state); +void fdmdv_set_fsep(struct FDMDV *fdmdv_state, float fsep); + +void fdmdv_mod(struct FDMDV *fdmdv_state, COMP tx_fdm[], int tx_bits[], int *sync_bit); +void fdmdv_demod(struct FDMDV *fdmdv_state, int rx_bits[], int *reliable_sync_bit, COMP rx_fdm[], int *nin); + +void fdmdv_get_test_bits(struct FDMDV *fdmdv_state, int tx_bits[]); +int fdmdv_error_pattern_size(struct FDMDV *fdmdv_state); +void fdmdv_put_test_bits(struct FDMDV *f, int *sync, short error_pattern[], int *bit_errors, int *ntest_bits, int rx_bits[]); + +void fdmdv_get_demod_stats(struct FDMDV *fdmdv_state, struct MODEM_STATS *stats); + +void fdmdv_8_to_16(float out16k[], float in8k[], int n); +void fdmdv_8_to_16_short(short out16k[], short in8k[], int n); +void fdmdv_16_to_8(float out8k[], float in16k[], int n); +void fdmdv_16_to_8_short(short out8k[], short in16k[], int n); +void fdmdv_8_to_48(float out48k[], float in8k[], int n); +void fdmdv_48_to_8(float out8k[], float in48k[], int n); +void fdmdv_8_to_48_short(short out48k[], short in8k[], int n); +void fdmdv_48_to_8_short(short out8k[], short in48k[], int n); + +void fdmdv_freq_shift(COMP rx_fdm_fcorr[], COMP rx_fdm[], float foff, COMP *foff_phase_rect, int nin); + +/* debug/development function(s) */ + +void fdmdv_dump_osc_mags(struct FDMDV *f); +void fdmdv_simulate_channel(float *sig_pwr_av, COMP samples[], int nin, float target_snr); + +#ifdef __cplusplus +} +#endif + +#endif |