spandsp
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00001 /* 00002 * SpanDSP - a series of DSP components for telephony 00003 * 00004 * udptl.c 00005 * 00006 * Written by Steve Underwood <steveu@coppice.org> 00007 * 00008 * Copyright (C) 2009 Steve Underwood 00009 * 00010 * All rights reserved. 00011 * 00012 * This program is free software; you can redistribute it and/or modify 00013 * it under the terms of the GNU General Public License version 2, as 00014 * published by the Free Software Foundation. 00015 * 00016 * This program is distributed in the hope that it will be useful, 00017 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00018 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00019 * GNU General Public License for more details. 00020 * 00021 * You should have received a copy of the GNU General Public License 00022 * along with this program; if not, write to the Free Software 00023 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 00024 */ 00025 00026 #if !defined(_SPANDSP_UDPTL_H_) 00027 #define _SPANDSP_UDPTL_H_ 00028 00029 #define LOCAL_FAX_MAX_DATAGRAM 400 00030 #define LOCAL_FAX_MAX_FEC_PACKETS 5 00031 00032 #define UDPTL_BUF_MASK 15 00033 00034 typedef int (udptl_rx_packet_handler_t) (void *user_data, const uint8_t msg[], int len, int seq_no); 00035 00036 typedef struct 00037 { 00038 int buf_len; 00039 uint8_t buf[LOCAL_FAX_MAX_DATAGRAM]; 00040 } udptl_fec_tx_buffer_t; 00041 00042 typedef struct 00043 { 00044 int buf_len; 00045 uint8_t buf[LOCAL_FAX_MAX_DATAGRAM]; 00046 int fec_len[LOCAL_FAX_MAX_FEC_PACKETS]; 00047 uint8_t fec[LOCAL_FAX_MAX_FEC_PACKETS][LOCAL_FAX_MAX_DATAGRAM]; 00048 int fec_span; 00049 int fec_entries; 00050 } udptl_fec_rx_buffer_t; 00051 00052 struct udptl_state_s 00053 { 00054 udptl_rx_packet_handler_t *rx_packet_handler; 00055 void *user_data; 00056 00057 /*! This option indicates the error correction scheme used in transmitted UDPTL 00058 packets. */ 00059 int error_correction_scheme; 00060 00061 /*! This option indicates the number of error correction entries transmitted in 00062 UDPTL packets. */ 00063 int error_correction_entries; 00064 00065 /*! This option indicates the span of the error correction entries in transmitted 00066 UDPTL packets (FEC only). */ 00067 int error_correction_span; 00068 00069 /*! This option indicates the maximum size of a datagram that can be accepted by 00070 the remote device. */ 00071 int far_max_datagram_size; 00072 00073 /*! This option indicates the maximum size of a datagram that we are prepared to 00074 accept. */ 00075 int local_max_datagram_size; 00076 00077 int verbose; 00078 00079 int tx_seq_no; 00080 int rx_seq_no; 00081 int rx_expected_seq_no; 00082 00083 udptl_fec_tx_buffer_t tx[UDPTL_BUF_MASK + 1]; 00084 udptl_fec_rx_buffer_t rx[UDPTL_BUF_MASK + 1]; 00085 }; 00086 00087 enum 00088 { 00089 UDPTL_ERROR_CORRECTION_NONE, 00090 UDPTL_ERROR_CORRECTION_FEC, 00091 UDPTL_ERROR_CORRECTION_REDUNDANCY 00092 }; 00093 00094 typedef struct udptl_state_s udptl_state_t; 00095 00096 #if defined(__cplusplus) 00097 extern "C" { 00098 #endif 00099 00100 /*! \brief Process an arriving UDPTL packet. 00101 \param s The UDPTL context. 00102 \param buf The UDPTL packet buffer. 00103 \param len The length of the packet. 00104 \return 0 for OK. */ 00105 int udptl_rx_packet(udptl_state_t *s, const uint8_t buf[], int len); 00106 00107 /*! \brief Construct a UDPTL packet, ready for transmission. 00108 \param s The UDPTL context. 00109 \param buf The UDPTL packet buffer. 00110 \param msg The primary packet. 00111 \param len The length of the primary packet. 00112 \return The length of the constructed UDPTL packet. */ 00113 int udptl_build_packet(udptl_state_t *s, uint8_t buf[], const uint8_t msg[], int msg_len); 00114 00115 /*! \brief Change the error correction settings of a UDPTL context. 00116 \param s The UDPTL context. 00117 \param ec_scheme One of the optional error correction schemes. 00118 \param span The packet span over which error correction should be applied. 00119 \param entries The number of error correction entries to include in packets. 00120 \return 0 for OK. */ 00121 int udptl_set_error_correction(udptl_state_t *s, int ec_scheme, int span, int entries); 00122 00123 /*! \brief Check the error correction settings of a UDPTL context. 00124 \param s The UDPTL context. 00125 \param ec_scheme One of the optional error correction schemes. 00126 \param span The packet span over which error correction is being applied. 00127 \param entries The number of error correction being included in packets. 00128 \return 0 for OK. */ 00129 int udptl_get_error_correction(udptl_state_t *s, int *ec_scheme, int *span, int *entries); 00130 00131 int udptl_set_local_max_datagram(udptl_state_t *s, int max_datagram); 00132 00133 int udptl_get_local_max_datagram(udptl_state_t *s); 00134 00135 int udptl_set_far_max_datagram(udptl_state_t *s, int max_datagram); 00136 00137 int udptl_get_far_max_datagram(udptl_state_t *s); 00138 00139 /*! \brief Initialise a UDPTL context. 00140 \param s The UDPTL context. 00141 \param ec_scheme One of the optional error correction schemes. 00142 \param span The packet span over which error correction should be applied. 00143 \param entries The number of error correction entries to include in packets. 00144 \param rx_packet_handler The callback function, used to report arriving IFP packets. 00145 \param user_data An opaque pointer supplied to rx_packet_handler. 00146 \return A pointer to the UDPTL context, or NULL if there was a problem. */ 00147 udptl_state_t *udptl_init(udptl_state_t *s, int ec_scheme, int span, int entries, udptl_rx_packet_handler_t rx_packet_handler, void *user_data); 00148 00149 /*! \brief Release a UDPTL context. 00150 \param s The UDPTL context. 00151 \return 0 for OK. */ 00152 int udptl_release(udptl_state_t *s); 00153 00154 #if defined(__cplusplus) 00155 } 00156 #endif 00157 #endif 00158 /*- End of file ------------------------------------------------------------*/