Philipp | 0b11db7 | 2016-08-01 18:13:40 +0200 | [diff] [blame] | 1 | /* |
| 2 | * SpanDSP - a series of DSP components for telephony |
| 3 | * |
| 4 | * private/v42bis.h |
| 5 | * |
| 6 | * Written by Steve Underwood <steveu@coppice.org> |
| 7 | * |
| 8 | * Copyright (C) 2005 Steve Underwood |
| 9 | * |
| 10 | * All rights reserved. |
| 11 | * |
| 12 | * This program is free software; you can redistribute it and/or modify |
| 13 | * it under the terms of the GNU Lesser General Public License version 2.1, |
| 14 | * as published by the Free Software Foundation. |
| 15 | * |
| 16 | * This program is distributed in the hope that it will be useful, |
| 17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 19 | * GNU Lesser General Public License for more details. |
| 20 | * |
| 21 | * You should have received a copy of the GNU Lesser General Public |
| 22 | * License along with this program; if not, write to the Free Software |
Max | 4f979bf | 2017-10-17 17:48:20 +0200 | [diff] [blame^] | 23 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
Philipp | 0b11db7 | 2016-08-01 18:13:40 +0200 | [diff] [blame] | 24 | */ |
| 25 | |
| 26 | #if !defined(_SPANDSP_PRIVATE_V42BIS_H_) |
| 27 | #define _SPANDSP_PRIVATE_V42BIS_H_ |
| 28 | |
| 29 | /*! |
| 30 | V.42bis dictionary node. |
| 31 | Note that 0 is not a valid node to point to (0 is always a control code), so 0 is used |
| 32 | as a "no such value" marker in this structure. |
| 33 | */ |
| 34 | typedef struct |
| 35 | { |
| 36 | /*! \brief The value of the octet represented by the current dictionary node */ |
| 37 | uint8_t node_octet; |
| 38 | /*! \brief The parent of this node */ |
| 39 | uint16_t parent; |
| 40 | /*! \brief The first child of this node */ |
| 41 | uint16_t child; |
| 42 | /*! \brief The next node at the same depth */ |
| 43 | uint16_t next; |
| 44 | } v42bis_dict_node_t; |
| 45 | |
| 46 | /*! |
| 47 | V.42bis compression or decompression. This defines the working state for a single instance |
| 48 | of V.42bis compression or decompression. |
| 49 | */ |
| 50 | typedef struct |
| 51 | { |
| 52 | /*! \brief Compression enabled. */ |
| 53 | int v42bis_parm_p0; |
| 54 | /*! \brief Compression mode. */ |
| 55 | int compression_mode; |
| 56 | /*! \brief Callback function to handle output data. */ |
| 57 | put_msg_func_t handler; |
| 58 | /*! \brief An opaque pointer passed in calls to the data handler. */ |
| 59 | void *user_data; |
| 60 | /*! \brief The maximum amount to be passed to the data handler. */ |
| 61 | int max_output_len; |
| 62 | |
| 63 | /*! \brief TRUE if we are in transparent (i.e. uncompressable) mode */ |
| 64 | int transparent; |
| 65 | /*! \brief Next empty dictionary entry */ |
| 66 | uint16_t v42bis_parm_c1; |
| 67 | /*! \brief Current codeword size */ |
| 68 | uint16_t v42bis_parm_c2; |
| 69 | /*! \brief Threshold for codeword size change */ |
| 70 | uint16_t v42bis_parm_c3; |
| 71 | /*! \brief The current update point in the dictionary */ |
| 72 | uint16_t update_at; |
| 73 | /*! \brief The last entry matched in the dictionary */ |
| 74 | uint16_t last_matched; |
| 75 | /*! \brief The last entry added to the dictionary */ |
| 76 | uint16_t last_added; |
| 77 | /*! \brief Total number of codewords in the dictionary */ |
| 78 | int v42bis_parm_n2; |
| 79 | /*! \brief Maximum permitted string length */ |
| 80 | int v42bis_parm_n7; |
| 81 | /*! \brief The dictionary */ |
| 82 | v42bis_dict_node_t dict[V42BIS_MAX_CODEWORDS]; |
| 83 | |
| 84 | /*! \brief The octet string in progress */ |
| 85 | uint8_t string[V42BIS_MAX_STRING_SIZE]; |
| 86 | /*! \brief The current length of the octet string in progress */ |
| 87 | int string_length; |
| 88 | /*! \brief The amount of the octet string in progress which has already |
| 89 | been flushed out of the buffer */ |
| 90 | int flushed_length; |
| 91 | |
| 92 | /*! \brief Compression performance metric */ |
| 93 | uint16_t compression_performance; |
| 94 | |
| 95 | /*! \brief Outgoing bit buffer (compression), or incoming bit buffer (decompression) */ |
| 96 | uint32_t bit_buffer; |
| 97 | /*! \brief Outgoing bit count (compression), or incoming bit count (decompression) */ |
| 98 | int bit_count; |
| 99 | |
| 100 | /*! \brief The output composition buffer */ |
| 101 | uint8_t output_buf[V42BIS_MAX_OUTPUT_LENGTH]; |
| 102 | /*! \brief The length of the contents of the output composition buffer */ |
| 103 | int output_octet_count; |
| 104 | |
| 105 | /*! \brief The current value of the escape code */ |
| 106 | uint8_t escape_code; |
| 107 | /*! \brief TRUE if we just hit an escape code, and are waiting for the following octet */ |
| 108 | int escaped; |
| 109 | } v42bis_comp_state_t; |
| 110 | |
| 111 | /*! |
| 112 | V.42bis compression/decompression descriptor. This defines the working state for a |
| 113 | single instance of V.42bis compress/decompression. |
| 114 | */ |
| 115 | struct v42bis_state_s |
| 116 | { |
| 117 | /*! \brief Compression state. */ |
| 118 | v42bis_comp_state_t compress; |
| 119 | /*! \brief Decompression state. */ |
| 120 | v42bis_comp_state_t decompress; |
| 121 | |
| 122 | /*! \brief Error and flow logging control */ |
Philipp | 0b11db7 | 2016-08-01 18:13:40 +0200 | [diff] [blame] | 123 | }; |
| 124 | |
| 125 | #endif |
| 126 | /*- End of file ------------------------------------------------------------*/ |