00001 /* 00002 * Asterisk -- An open source telephony toolkit. 00003 * 00004 * Copyright (C) 2005, Anthony Minessale II 00005 * 00006 * Anthony Minessale <anthmct@yahoo.com> 00007 * 00008 * See http://www.asterisk.org for more information about 00009 * the Asterisk project. Please do not directly contact 00010 * any of the maintainers of this project for assistance; 00011 * the project provides a web site, mailing lists and IRC 00012 * channels for your use. 00013 * 00014 * This program is free software, distributed under the terms of 00015 * the GNU General Public License Version 2. See the LICENSE file 00016 * at the top of the source tree. 00017 */ 00018 00019 /*! \file 00020 * \brief A machine to gather up arbitrary frames and convert them 00021 * to raw slinear on demand. 00022 */ 00023 00024 #ifndef _ASTERISK_SLINFACTORY_H 00025 #define _ASTERISK_SLINFACTORY_H 00026 00027 #if defined(__cplusplus) || defined(c_plusplus) 00028 extern "C" { 00029 #endif 00030 00031 #define AST_SLINFACTORY_MAX_HOLD 1280 00032 00033 struct ast_slinfactory { 00034 AST_LIST_HEAD_NOLOCK(, ast_frame) queue; /*!< A list of unaltered frames */ 00035 struct ast_trans_pvt *trans; /*!< Translation path that converts fed frames into signed linear */ 00036 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) */ 00037 short *offset; /*!< Offset into the hold where audio begins */ 00038 size_t holdlen; /*!< Number of samples currently in the hold */ 00039 unsigned int size; /*!< Number of samples currently in the factory */ 00040 format_t format; /*!< Current format the translation path is converting from */ 00041 format_t output_format; /*!< The output format desired */ 00042 }; 00043 00044 /*! 00045 * \brief Initialize a slinfactory 00046 * 00047 * \param sf The slinfactory to initialize 00048 * 00049 * \return Nothing 00050 */ 00051 void ast_slinfactory_init(struct ast_slinfactory *sf); 00052 00053 /*! 00054 * \brief Initialize a slinfactory 00055 * 00056 * \param sf The slinfactory to initialize 00057 * \param sample_rate The output sample rate desired 00058 * 00059 * \return 0 on success, non-zero on failure 00060 */ 00061 int ast_slinfactory_init_rate(struct ast_slinfactory *sf, unsigned int sample_rate); 00062 00063 /*! 00064 * \brief Destroy the contents of a slinfactory 00065 * 00066 * \param sf The slinfactory that is no longer needed 00067 * 00068 * This function will free any memory allocated for the contents of the 00069 * slinfactory. It does not free the slinfactory itself. If the sf is 00070 * malloc'd, then it must be explicitly free'd after calling this function. 00071 * 00072 * \return Nothing 00073 */ 00074 void ast_slinfactory_destroy(struct ast_slinfactory *sf); 00075 00076 /*! 00077 * \brief Feed audio into a slinfactory 00078 * 00079 * \param sf The slinfactory to feed into 00080 * \param f Frame containing audio to feed in 00081 * 00082 * \return Number of frames currently in factory 00083 */ 00084 int ast_slinfactory_feed(struct ast_slinfactory *sf, struct ast_frame *f); 00085 00086 /*! 00087 * \brief Read samples from a slinfactory 00088 * 00089 * \param sf The slinfactory to read from 00090 * \param buf Buffer to put samples into 00091 * \param samples Number of samples wanted 00092 * 00093 * \return Number of samples read 00094 */ 00095 int ast_slinfactory_read(struct ast_slinfactory *sf, short *buf, size_t samples); 00096 00097 /*! 00098 * \brief Retrieve number of samples currently in a slinfactory 00099 * 00100 * \param sf The slinfactory to peek into 00101 * 00102 * \return Number of samples in slinfactory 00103 */ 00104 unsigned int ast_slinfactory_available(const struct ast_slinfactory *sf); 00105 00106 /*! 00107 * \brief Flush the contents of a slinfactory 00108 * 00109 * \param sf The slinfactory to flush 00110 * 00111 * \return Nothing 00112 */ 00113 void ast_slinfactory_flush(struct ast_slinfactory *sf); 00114 00115 #if defined(__cplusplus) || defined(c_plusplus) 00116 } 00117 #endif 00118 00119 #endif /* _ASTERISK_SLINFACTORY_H */