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/**
* \file include/pcm_rate.h
* \brief External Rate-Converter-Plugin SDK
* \author Takashi Iwai <tiwai@suse.de>
* \date 2006
*
* External Rate-Converter-Plugin SDK
*/
/*
* ALSA external PCM rate-converter plugin SDK (draft version)
*
* Copyright (c) 2006 Takashi Iwai <tiwai@suse.de>
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#ifndef __ALSA_PCM_RATE_H
#define __ALSA_PCM_RATE_H
#ifdef __cplusplus
extern "C" {
#endif
/**
* Protocol version
*/
#define SND_PCM_RATE_PLUGIN_VERSION 0x010001
/** hw_params information for a single side */
typedef struct snd_pcm_rate_side_info {
snd_pcm_format_t format;
unsigned int rate;
snd_pcm_uframes_t buffer_size;
snd_pcm_uframes_t period_size;
} snd_pcm_rate_side_info_t;
/** hw_params information */
typedef struct snd_pcm_rate_info {
struct snd_pcm_rate_side_info in;
struct snd_pcm_rate_side_info out;
unsigned int channels;
} snd_pcm_rate_info_t;
/** Callback table of rate-converter */
typedef struct snd_pcm_rate_ops {
/**
* close the converter; optional
*/
void (*close)(void *obj);
/**
* initialize the converter, called at hw_params
*/
int (*init)(void *obj, snd_pcm_rate_info_t *info);
/**
* free the converter; optional
*/
void (*free)(void *obj);
/**
* reset the converter, called at prepare; optional
*/
void (*reset)(void *obj);
/**
* adjust the pitch, called at sw_params; optional
*/
int (*adjust_pitch)(void *obj, snd_pcm_rate_info_t *info);
/**
* convert the data
*/
void (*convert)(void *obj,
const snd_pcm_channel_area_t *dst_areas,
snd_pcm_uframes_t dst_offset, unsigned int dst_frames,
const snd_pcm_channel_area_t *src_areas,
snd_pcm_uframes_t src_offset, unsigned int src_frames);
/**
* convert an s16 interleaved-data array; exclusive with convert
*/
void (*convert_s16)(void *obj, int16_t *dst, unsigned int dst_frames,
const int16_t *src, unsigned int src_frames);
/**
* compute the frame size for input
*/
snd_pcm_uframes_t (*input_frames)(void *obj, snd_pcm_uframes_t frames);
/**
* compute the frame size for output
*/
snd_pcm_uframes_t (*output_frames)(void *obj, snd_pcm_uframes_t frames);
} snd_pcm_rate_ops_t;
/** open function type */
typedef int (*snd_pcm_rate_open_func_t)(unsigned int version, void **objp,
snd_pcm_rate_ops_t *opsp);
/**
* Define the object entry for external PCM rate-converter plugins
*/
#define SND_PCM_RATE_PLUGIN_ENTRY(name) _snd_pcm_rate_##name##_open
#ifdef __cplusplus
}
#endif
#endif /* __ALSA_PCM_RATE_H */
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