k3b/libk3b/plugin/libsamplerate/samplerate.h

/*
** Copyright (C) 2002,2003 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., 51 Franklin Steet, Fifth Floor, Boston, MA 02110-1301, USA.
*/

/*
** 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 */

typedef struct SRC_STATE_tag SRC_STATE ;

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 ;

/*
**	Simple interface for performing a single conversion from input buffer to
** output buffer at a fixed conversion ratio.
*/
int src_simple (SRC_DATA *data, int converter_type, int channels) ;

/*
**	Initialisation function : return an anonymous pointer to the internal state
**	of the converter. Choose a converter from the enums below.
*/

SRC_STATE* src_new (int converter_type, int channels, int *error) ;

/*
**	Cleanup all internal allocations.
**	Always returns NULL.
*/

SRC_STATE* src_delete (SRC_STATE *state) ;

/*
** 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) ;

/*
**	Processing function.
**	Returns non zero on error.
*/

int src_process (SRC_STATE *state, SRC_DATA *data) ;

/*
**	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_TQUALITY		= 0,
	SRC_SINC_MEDIUM_TQUALITY		= 1,
	SRC_SINC_FASTEST			= 2,
	SRC_ZERO_ORDER_HOLD			= 3,
	SRC_LINEAR					= 4
} ;


#ifdef __cplusplus
}		/* extern "C" */
#endif	/* __cplusplus */

#endif	/* SAMPLERATE_H */