| /* |
| ** Copyright (C) 2002-2011 Erik de Castro Lopo <erikd@mega-nerd.com> |
| ** |
| ** This program is free software; you can redistribute it and/or modify |
| ** it under the terms of the GNU General Public License as published by |
| ** the Free Software Foundation; either version 2 of the License, or |
| ** (at your option) any later version. |
| ** |
| ** 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 General Public License |
| ** along with this program; if not, write to the Free Software |
| ** Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA. |
| */ |
| |
| /* |
| ** This code is part of Secret Rabbit Code aka libsamplerate. A commercial |
| ** use license for this code is available, please see: |
| ** http://www.mega-nerd.com/SRC/procedure.html |
| */ |
| |
| /* |
| ** API documentation is available here: |
| ** http://www.mega-nerd.com/SRC/api.html |
| */ |
| |
| #ifndef SAMPLERATE_H |
| #define SAMPLERATE_H |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif /* __cplusplus */ |
| |
| |
| /* Opaque data type SRC_STATE. */ |
| typedef struct SRC_STATE_tag SRC_STATE ; |
| |
| /* SRC_DATA is used to pass data to src_simple() and src_process(). */ |
| typedef struct |
| { float *data_in, *data_out ; |
| |
| long input_frames, output_frames ; |
| long input_frames_used, output_frames_gen ; |
| |
| int end_of_input ; |
| |
| double src_ratio ; |
| } SRC_DATA ; |
| |
| /* SRC_CB_DATA is used with callback based API. */ |
| typedef struct |
| { long frames ; |
| float *data_in ; |
| } SRC_CB_DATA ; |
| |
| /* |
| ** User supplied callback function type for use with src_callback_new() |
| ** and src_callback_read(). First parameter is the same pointer that was |
| ** passed into src_callback_new(). Second parameter is pointer to a |
| ** pointer. The user supplied callback function must modify *data to |
| ** point to the start of the user supplied float array. The user supplied |
| ** function must return the number of frames that **data points to. |
| */ |
| |
| typedef long (*src_callback_t) (void *cb_data, float **data) ; |
| |
| /* |
| ** Standard initialisation function : return an anonymous pointer to the |
| ** internal state of the converter. Choose a converter from the enums below. |
| ** Error returned in *error. |
| */ |
| |
| SRC_STATE* src_new (int converter_type, int channels, int *error) ; |
| |
| /* |
| ** Initilisation for callback based API : return an anonymous pointer to the |
| ** internal state of the converter. Choose a converter from the enums below. |
| ** The cb_data pointer can point to any data or be set to NULL. Whatever the |
| ** value, when processing, user supplied function "func" gets called with |
| ** cb_data as first parameter. |
| */ |
| |
| SRC_STATE* src_callback_new (src_callback_t func, int converter_type, int channels, |
| int *error, void* cb_data) ; |
| |
| /* |
| ** Cleanup all internal allocations. |
| ** Always returns NULL. |
| */ |
| |
| SRC_STATE* src_delete (SRC_STATE *state) ; |
| |
| /* |
| ** Standard processing function. |
| ** Returns non zero on error. |
| */ |
| |
| int src_process (SRC_STATE *state, SRC_DATA *data) ; |
| |
| /* |
| ** Callback based processing function. Read up to frames worth of data from |
| ** the converter int *data and return frames read or -1 on error. |
| */ |
| long src_callback_read (SRC_STATE *state, double src_ratio, long frames, float *data) ; |
| |
| /* |
| ** Simple interface for performing a single conversion from input buffer to |
| ** output buffer at a fixed conversion ratio. |
| ** Simple interface does not require initialisation as it can only operate on |
| ** a single buffer worth of audio. |
| */ |
| |
| int src_simple (SRC_DATA *data, int converter_type, int channels) ; |
| |
| /* |
| ** This library contains a number of different sample rate converters, |
| ** numbered 0 through N. |
| ** |
| ** Return a string giving either a name or a more full description of each |
| ** sample rate converter or NULL if no sample rate converter exists for |
| ** the given value. The converters are sequentially numbered from 0 to N. |
| */ |
| |
| const char *src_get_name (int converter_type) ; |
| const char *src_get_description (int converter_type) ; |
| const char *src_get_version (void) ; |
| |
| /* |
| ** Set a new SRC ratio. This allows step responses |
| ** in the conversion ratio. |
| ** Returns non zero on error. |
| */ |
| |
| int src_set_ratio (SRC_STATE *state, double new_ratio) ; |
| |
| /* |
| ** Reset the internal SRC state. |
| ** Does not modify the quality settings. |
| ** Does not free any memory allocations. |
| ** Returns non zero on error. |
| */ |
| |
| int src_reset (SRC_STATE *state) ; |
| |
| /* |
| ** Return TRUE if ratio is a valid conversion ratio, FALSE |
| ** otherwise. |
| */ |
| |
| int src_is_valid_ratio (double ratio) ; |
| |
| /* |
| ** Return an error number. |
| */ |
| |
| int src_error (SRC_STATE *state) ; |
| |
| /* |
| ** Convert the error number into a string. |
| */ |
| const char* src_strerror (int error) ; |
| |
| /* |
| ** The following enums can be used to set the interpolator type |
| ** using the function src_set_converter(). |
| */ |
| |
| enum |
| { |
| SRC_SINC_BEST_QUALITY = 0, |
| SRC_SINC_MEDIUM_QUALITY = 1, |
| SRC_SINC_FASTEST = 2, |
| SRC_ZERO_ORDER_HOLD = 3, |
| SRC_LINEAR = 4, |
| } ; |
| |
| /* |
| ** Extra helper functions for converting from short to float and |
| ** back again. |
| */ |
| |
| void src_short_to_float_array (const short *in, float *out, int len) ; |
| void src_float_to_short_array (const float *in, short *out, int len) ; |
| |
| void src_int_to_float_array (const int *in, float *out, int len) ; |
| void src_float_to_int_array (const float *in, int *out, int len) ; |
| |
| |
| #ifdef __cplusplus |
| } /* extern "C" */ |
| #endif /* __cplusplus */ |
| |
| #endif /* SAMPLERATE_H */ |
| |