You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
dvmhost/src/bridge/mdc/mdc_encode.h

144 lines
4.6 KiB

// SPDX-License-Identifier: GPL-2.0-only
/*
* Digital Voice Modem - Bridge
* GPLv2 Open Source. Use is subject to license terms.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
*/
/**
* @file mdc_encode.h
* @ingroup bridge
* @file mdc_encode.c
* @ingroup bridge
*/
/*-
* mdc_encode.h
* header for mdc_encode.c
*
* 9 October 2010 - typedefs for easier porting
*
* Author: Matthew Kaufman (matthew@eeph.com)
*
* Copyright (c) 2005 Matthew Kaufman All rights reserved.
*
* This file is part of Matthew Kaufman's MDC Encoder/Decoder Library
*
* The MDC Encoder/Decoder Library is free software; you can
* redistribute it and/or modify it under the terms of version 2 of
* the GNU General Public License as published by the Free Software
* Foundation.
*
* If you cannot comply with the terms of this license, contact
* the author for alternative license arrangements or do not use
* or redistribute this software.
*
* The MDC Encoder/Decoder Library 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 General Public License
* along with this software; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301
* USA.
*
* or see http://www.gnu.org/copyleft/gpl.html
*
-*/
#if !defined(__MDC_ENCODE_H__)
#define __MDC_ENCODE_H__
#include "mdc/mdc_types.h"
//#define FILL_FINAL // fills the end of the last block with zeros, rather than returning fewer samples than requested
//#define MDC_ENCODE_FULL_AMPLITUDE // encode at 100% amplitude (default is 68% amplitude for recommended deviation)
// ---------------------------------------------------------------------------
// Structure Declaration
// ---------------------------------------------------------------------------
/**
* @brief
*/
typedef struct {
mdc_int_t loaded;
mdc_int_t bpos;
mdc_int_t ipos;
mdc_int_t preamble_set;
mdc_int_t preamble_count;
mdc_u32_t thu;
mdc_u32_t tthu;
mdc_u32_t incru;
mdc_u32_t incru18;
mdc_int_t state;
mdc_int_t lb;
mdc_int_t xorb;
mdc_u8_t data[14 + 14 + 5 + 7];
} mdc_encoder_t;
// ---------------------------------------------------------------------------
// Global Functions
// ---------------------------------------------------------------------------
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief Create a new mdc_encoder object.
* @param sampleRate The sampling rate in Hz.
* @returns mdc_encoder_t* An mdc_encoder object or null if failure.
*/
mdc_encoder_t* mdc_encoder_new(int sampleRate);
/**
* @brief
* @param[in] encoder Instance of mdc_encoder object.
* @param preambleLength length of additional preamble (in bytes) - preamble time is 6.66 msec * preambleLength.
* @returns int -1 for error, 0 otherwise
*/
int mdc_encoder_set_preamble(mdc_encoder_t* encoder, int preambleLength);
/**
* @brief Set up a normal-length MDC packet for transmission.
* @param[in] encoder Instance of mdc_encoder object.
* @param op MDC Opcode.
* @param arg MDC Argument.
* @param unitID Unit ID.
* @returns int -1 for error, 0 otherwise
*/
int mdc_encoder_set_packet(mdc_encoder_t* encoder, mdc_u8_t op, mdc_u8_t arg, mdc_u16_t unitID);
/**
* @brief Set up a double-length MDC packet for transmission.
* @param[in] encoder Instance of mdc_encoder object.
* @param op MDC Opcode.
* @param arg MDC Argument.
* @param unitID Unit ID.
* @param extra0 1st extra byte.
* @param extra1 2nd extra byte.
* @param extra2 3rd extra byte.
* @param extra3 4th extra byte.
* @returns int -1 for error, 0 otherwise
*/
int mdc_encoder_set_double_packet(mdc_encoder_t* encoder, mdc_u8_t op, mdc_u8_t arg,
mdc_u16_t unitID, mdc_u8_t extra0, mdc_u8_t extra1, mdc_u8_t extra2, mdc_u8_t extra3);
/**
* @brief Get generated output audio samples from encoder.
* @param[out] buffer Sample buffer to write into.
* @param[out] bufferSize The size (in samples) of the sample buffer.
* @returns int -1 for error, otherwise returns the number of samples written
* into the buffer (will be equal to bufferSize unless the end has
* been reached, in which case the last block may be less than
* bufferSize and all subsequent calls will return zero, until
* a new packet is loaded for transmission
*/
int mdc_encoder_get_samples(mdc_encoder_t* encoder, mdc_sample_t* buffer, int bufferSize);
#ifdef __cplusplus
}
#endif
#endif // __MDC_ENCODE_H__

Powered by TurnKey Linux.