Emeric Vigier | eebea67 | 2012-08-06 17:36:30 -0400 | [diff] [blame] | 1 | /* |
| 2 | ** Copyright (C) 2002-2011 Erik de Castro Lopo <erikd@mega-nerd.com> |
| 3 | ** |
| 4 | ** This program is free software; you can redistribute it and/or modify |
| 5 | ** it under the terms of the GNU General Public License as published by |
| 6 | ** the Free Software Foundation; either version 2 of the License, or |
| 7 | ** (at your option) any later version. |
| 8 | ** |
| 9 | ** This program is distributed in the hope that it will be useful, |
| 10 | ** but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | ** GNU General Public License for more details. |
| 13 | ** |
| 14 | ** You should have received a copy of the GNU General Public License |
| 15 | ** along with this program; if not, write to the Free Software |
| 16 | ** Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA. |
| 17 | */ |
| 18 | |
| 19 | /* |
| 20 | ** This code is part of Secret Rabbit Code aka libsamplerate. A commercial |
| 21 | ** use license for this code is available, please see: |
| 22 | ** http://www.mega-nerd.com/SRC/procedure.html |
| 23 | */ |
| 24 | |
| 25 | /* |
| 26 | ** API documentation is available here: |
| 27 | ** http://www.mega-nerd.com/SRC/api.html |
| 28 | */ |
| 29 | |
| 30 | #ifndef SAMPLERATE_H |
| 31 | #define SAMPLERATE_H |
| 32 | |
| 33 | #ifdef __cplusplus |
| 34 | extern "C" { |
| 35 | #endif /* __cplusplus */ |
| 36 | |
| 37 | |
| 38 | /* Opaque data type SRC_STATE. */ |
| 39 | typedef struct SRC_STATE_tag SRC_STATE ; |
| 40 | |
| 41 | /* SRC_DATA is used to pass data to src_simple() and src_process(). */ |
| 42 | typedef struct |
| 43 | { float *data_in, *data_out ; |
| 44 | |
| 45 | long input_frames, output_frames ; |
| 46 | long input_frames_used, output_frames_gen ; |
| 47 | |
| 48 | int end_of_input ; |
| 49 | |
| 50 | double src_ratio ; |
| 51 | } SRC_DATA ; |
| 52 | |
| 53 | /* SRC_CB_DATA is used with callback based API. */ |
| 54 | typedef struct |
| 55 | { long frames ; |
| 56 | float *data_in ; |
| 57 | } SRC_CB_DATA ; |
| 58 | |
| 59 | /* |
| 60 | ** User supplied callback function type for use with src_callback_new() |
| 61 | ** and src_callback_read(). First parameter is the same pointer that was |
| 62 | ** passed into src_callback_new(). Second parameter is pointer to a |
| 63 | ** pointer. The user supplied callback function must modify *data to |
| 64 | ** point to the start of the user supplied float array. The user supplied |
| 65 | ** function must return the number of frames that **data points to. |
| 66 | */ |
| 67 | |
| 68 | typedef long (*src_callback_t) (void *cb_data, float **data) ; |
| 69 | |
| 70 | /* |
| 71 | ** Standard initialisation function : return an anonymous pointer to the |
| 72 | ** internal state of the converter. Choose a converter from the enums below. |
| 73 | ** Error returned in *error. |
| 74 | */ |
| 75 | |
| 76 | SRC_STATE* src_new (int converter_type, int channels, int *error) ; |
| 77 | |
| 78 | /* |
| 79 | ** Initilisation for callback based API : return an anonymous pointer to the |
| 80 | ** internal state of the converter. Choose a converter from the enums below. |
| 81 | ** The cb_data pointer can point to any data or be set to NULL. Whatever the |
| 82 | ** value, when processing, user supplied function "func" gets called with |
| 83 | ** cb_data as first parameter. |
| 84 | */ |
| 85 | |
| 86 | SRC_STATE* src_callback_new (src_callback_t func, int converter_type, int channels, |
| 87 | int *error, void* cb_data) ; |
| 88 | |
| 89 | /* |
| 90 | ** Cleanup all internal allocations. |
| 91 | ** Always returns NULL. |
| 92 | */ |
| 93 | |
| 94 | SRC_STATE* src_delete (SRC_STATE *state) ; |
| 95 | |
| 96 | /* |
| 97 | ** Standard processing function. |
| 98 | ** Returns non zero on error. |
| 99 | */ |
| 100 | |
| 101 | int src_process (SRC_STATE *state, SRC_DATA *data) ; |
| 102 | |
| 103 | /* |
| 104 | ** Callback based processing function. Read up to frames worth of data from |
| 105 | ** the converter int *data and return frames read or -1 on error. |
| 106 | */ |
| 107 | long src_callback_read (SRC_STATE *state, double src_ratio, long frames, float *data) ; |
| 108 | |
| 109 | /* |
| 110 | ** Simple interface for performing a single conversion from input buffer to |
| 111 | ** output buffer at a fixed conversion ratio. |
| 112 | ** Simple interface does not require initialisation as it can only operate on |
| 113 | ** a single buffer worth of audio. |
| 114 | */ |
| 115 | |
| 116 | int src_simple (SRC_DATA *data, int converter_type, int channels) ; |
| 117 | |
| 118 | /* |
| 119 | ** This library contains a number of different sample rate converters, |
| 120 | ** numbered 0 through N. |
| 121 | ** |
| 122 | ** Return a string giving either a name or a more full description of each |
| 123 | ** sample rate converter or NULL if no sample rate converter exists for |
| 124 | ** the given value. The converters are sequentially numbered from 0 to N. |
| 125 | */ |
| 126 | |
| 127 | const char *src_get_name (int converter_type) ; |
| 128 | const char *src_get_description (int converter_type) ; |
| 129 | const char *src_get_version (void) ; |
| 130 | |
| 131 | /* |
| 132 | ** Set a new SRC ratio. This allows step responses |
| 133 | ** in the conversion ratio. |
| 134 | ** Returns non zero on error. |
| 135 | */ |
| 136 | |
| 137 | int src_set_ratio (SRC_STATE *state, double new_ratio) ; |
| 138 | |
| 139 | /* |
| 140 | ** Reset the internal SRC state. |
| 141 | ** Does not modify the quality settings. |
| 142 | ** Does not free any memory allocations. |
| 143 | ** Returns non zero on error. |
| 144 | */ |
| 145 | |
| 146 | int src_reset (SRC_STATE *state) ; |
| 147 | |
| 148 | /* |
| 149 | ** Return TRUE if ratio is a valid conversion ratio, FALSE |
| 150 | ** otherwise. |
| 151 | */ |
| 152 | |
| 153 | int src_is_valid_ratio (double ratio) ; |
| 154 | |
| 155 | /* |
| 156 | ** Return an error number. |
| 157 | */ |
| 158 | |
| 159 | int src_error (SRC_STATE *state) ; |
| 160 | |
| 161 | /* |
| 162 | ** Convert the error number into a string. |
| 163 | */ |
| 164 | const char* src_strerror (int error) ; |
| 165 | |
| 166 | /* |
| 167 | ** The following enums can be used to set the interpolator type |
| 168 | ** using the function src_set_converter(). |
| 169 | */ |
| 170 | |
| 171 | enum |
| 172 | { |
| 173 | SRC_SINC_BEST_QUALITY = 0, |
| 174 | SRC_SINC_MEDIUM_QUALITY = 1, |
| 175 | SRC_SINC_FASTEST = 2, |
| 176 | SRC_ZERO_ORDER_HOLD = 3, |
| 177 | SRC_LINEAR = 4, |
| 178 | } ; |
| 179 | |
| 180 | /* |
| 181 | ** Extra helper functions for converting from short to float and |
| 182 | ** back again. |
| 183 | */ |
| 184 | |
| 185 | void src_short_to_float_array (const short *in, float *out, int len) ; |
| 186 | void src_float_to_short_array (const float *in, short *out, int len) ; |
| 187 | |
| 188 | void src_int_to_float_array (const int *in, float *out, int len) ; |
| 189 | void src_float_to_int_array (const float *in, int *out, int len) ; |
| 190 | |
| 191 | |
| 192 | #ifdef __cplusplus |
| 193 | } /* extern "C" */ |
| 194 | #endif /* __cplusplus */ |
| 195 | |
| 196 | #endif /* SAMPLERATE_H */ |
| 197 | |