asterisk/include/asterisk/slinfactory.h

117 lines
3.5 KiB
C

/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 2005, Anthony Minessale II
*
* Anthony Minessale <anthmct@yahoo.com>
*
* See http://www.asterisk.org for more information about
* the Asterisk project. Please do not directly contact
* any of the maintainers of this project for assistance;
* the project provides a web site, mailing lists and IRC
* channels for your use.
*
* This program is free software, distributed under the terms of
* the GNU General Public License Version 2. See the LICENSE file
* at the top of the source tree.
*/
/*! \file
* \brief A machine to gather up arbitrary frames and convert them
* to raw slinear on demand.
*/
#ifndef _ASTERISK_SLINFACTORY_H
#define _ASTERISK_SLINFACTORY_H
#include "asterisk/format.h"
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif
#define AST_SLINFACTORY_MAX_HOLD 1280
struct ast_slinfactory {
AST_LIST_HEAD_NOLOCK(, ast_frame) queue; /*!< A list of unaltered frames */
struct ast_trans_pvt *trans; /*!< Translation path that converts fed frames into signed linear */
short hold[AST_SLINFACTORY_MAX_HOLD]; /*!< Hold for audio that no longer belongs to a frame (ie: if only some samples were taken from a frame) */
short *offset; /*!< Offset into the hold where audio begins */
size_t holdlen; /*!< Number of samples currently in the hold */
unsigned int size; /*!< Number of samples currently in the factory */
struct ast_format *format; /*!< Current format the translation path is converting from */
struct ast_format *output_format; /*!< The output format desired */
};
/*!
* \brief Initialize a slinfactory
*
* \param sf The slinfactory to initialize
*/
void ast_slinfactory_init(struct ast_slinfactory *sf);
/*!
* \brief Initialize a slinfactory
*
* \param sf The slinfactory to initialize
* \param slin_out the slinear output format desired.
*
* \retval 0 on success
* \retval non-zero on failure
*/
int ast_slinfactory_init_with_format(struct ast_slinfactory *sf, struct ast_format *slin_out);
/*!
* \brief Destroy the contents of a slinfactory
*
* \param sf The slinfactory that is no longer needed
*
* This function will free any memory allocated for the contents of the
* slinfactory. It does not free the slinfactory itself. If the sf is
* malloc'd, then it must be explicitly free'd after calling this function.
*/
void ast_slinfactory_destroy(struct ast_slinfactory *sf);
/*!
* \brief Feed audio into a slinfactory
*
* \param sf The slinfactory to feed into
* \param f Frame containing audio to feed in
*
* \return Number of frames currently in factory
*/
int ast_slinfactory_feed(struct ast_slinfactory *sf, struct ast_frame *f);
/*!
* \brief Read samples from a slinfactory
*
* \param sf The slinfactory to read from
* \param buf Buffer to put samples into
* \param samples Number of samples wanted
*
* \return Number of samples read
*/
int ast_slinfactory_read(struct ast_slinfactory *sf, short *buf, size_t samples);
/*!
* \brief Retrieve number of samples currently in a slinfactory
*
* \param sf The slinfactory to peek into
*
* \return Number of samples in slinfactory
*/
unsigned int ast_slinfactory_available(const struct ast_slinfactory *sf);
/*!
* \brief Flush the contents of a slinfactory
*
* \param sf The slinfactory to flush
*/
void ast_slinfactory_flush(struct ast_slinfactory *sf);
#if defined(__cplusplus) || defined(c_plusplus)
}
#endif
#endif /* _ASTERISK_SLINFACTORY_H */