X-Git-Url: http://git.ieval.ro/?a=blobdiff_plain;f=libsamplerate%2Fsrc%2Fsamplerate.h;fp=libsamplerate%2Fsrc%2Fsamplerate.h;h=ac0f2b085078bf3ab88a5d43ccc5ccd389d98076;hb=8529da432e52c7903e8ef3488e60725a099e6e63;hp=0000000000000000000000000000000000000000;hpb=27013d8f68878b8ed2d3f747e26f562d08d7d678;p=audio-libsamplerate.git diff --git a/libsamplerate/src/samplerate.h b/libsamplerate/src/samplerate.h new file mode 100644 index 0000000..ac0f2b0 --- /dev/null +++ b/libsamplerate/src/samplerate.h @@ -0,0 +1,183 @@ +/* +** Copyright (c) 2002-2016, Erik de Castro Lopo +** All rights reserved. +** +** This code is released under 2-clause BSD license. Please see the +** file at : https://github.com/erikd/libsamplerate/blob/master/COPYING +*/ + +/* +** 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 +{ const float *data_in ; + float *data_out ; + + long input_frames, output_frames ; + long input_frames_used, output_frames_gen ; + + int end_of_input ; + + double src_ratio ; +} SRC_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) ; + +/* +** Get the current channel count. +** Returns negative on error, positive channel count otherwise +*/ + +int src_get_channels (SRC_STATE *state) ; + +/* +** 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 */ +