Sun Jun 12 16:37:44 2011

Asterisk developer's documentation


audiohook.h

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (C) 1999 - 2007, Digium, Inc.
00005  *
00006  * Joshua Colp <jcolp@digium.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 Audiohooks Architecture
00021  */
00022 
00023 #ifndef _ASTERISK_AUDIOHOOK_H
00024 #define _ASTERISK_AUDIOHOOK_H
00025 
00026 #if defined(__cplusplus) || defined(c_plusplus)
00027 extern "C" {
00028 #endif
00029 
00030 #include "asterisk/slinfactory.h"
00031 
00032 enum ast_audiohook_type {
00033    AST_AUDIOHOOK_TYPE_SPY = 0,    /*!< Audiohook wants to receive audio */
00034    AST_AUDIOHOOK_TYPE_WHISPER,    /*!< Audiohook wants to provide audio to be mixed with existing audio */
00035    AST_AUDIOHOOK_TYPE_MANIPULATE, /*!< Audiohook wants to manipulate the audio */
00036 };
00037 
00038 enum ast_audiohook_status {
00039    AST_AUDIOHOOK_STATUS_NEW = 0,  /*!< Audiohook was just created, not in use yet */
00040    AST_AUDIOHOOK_STATUS_RUNNING,  /*!< Audiohook is running on a channel */
00041    AST_AUDIOHOOK_STATUS_SHUTDOWN, /*!< Audiohook is being shutdown */
00042    AST_AUDIOHOOK_STATUS_DONE,     /*!< Audiohook has shutdown and is not running on a channel any longer */
00043 };
00044 
00045 enum ast_audiohook_direction {
00046    AST_AUDIOHOOK_DIRECTION_READ = 0, /*!< Reading audio in */
00047    AST_AUDIOHOOK_DIRECTION_WRITE,    /*!< Writing audio out */
00048    AST_AUDIOHOOK_DIRECTION_BOTH,     /*!< Both reading audio in and writing audio out */
00049 };
00050 
00051 enum ast_audiohook_flags {
00052    AST_AUDIOHOOK_TRIGGER_MODE = (3 << 0),  /*!< When audiohook should be triggered to do something */
00053    AST_AUDIOHOOK_TRIGGER_READ = (1 << 0),  /*!< Audiohook wants to be triggered when reading audio in */
00054    AST_AUDIOHOOK_TRIGGER_WRITE = (2 << 0), /*!< Audiohook wants to be triggered when writing audio out */
00055    AST_AUDIOHOOK_WANTS_DTMF = (1 << 1),    /*!< Audiohook also wants to receive DTMF frames */
00056    AST_AUDIOHOOK_TRIGGER_SYNC = (1 << 2),  /*!< Audiohook wants to be triggered when both sides have combined audio available */
00057 };
00058 
00059 struct ast_audiohook;
00060 
00061 /*! \brief Callback function for manipulate audiohook type
00062  * \param audiohook Audiohook structure
00063  * \param chan Channel
00064  * \param frame Frame of audio to manipulate
00065  * \param direction Direction frame came from
00066  * \return Returns 0 on success, -1 on failure
00067  * \note An audiohook does not have any reference to a private data structure for manipulate types. It is up to the manipulate callback to store this data
00068  *       via it's own method. An example would be datastores.
00069  */
00070 typedef int (*ast_audiohook_manipulate_callback)(struct ast_audiohook *audiohook, struct ast_channel *chan, struct ast_frame *frame, enum ast_audiohook_direction direction);
00071 
00072 struct ast_audiohook_options {
00073    int read_volume;  /*!< Volume adjustment on frames read from the channel the hook is on */
00074    int write_volume; /*!< Volume adjustment on frames written to the channel the hook is on */
00075 };
00076 
00077 struct ast_audiohook {
00078    ast_mutex_t lock;                                      /*!< Lock that protects the audiohook structure */
00079    ast_cond_t trigger;                                    /*!< Trigger condition (if enabled) */
00080    enum ast_audiohook_type type;                          /*!< Type of audiohook */
00081    enum ast_audiohook_status status;                      /*!< Status of the audiohook */
00082    const char *source;                                    /*!< Who this audiohook ultimately belongs to */
00083    unsigned int flags;                                    /*!< Flags on the audiohook */
00084    struct ast_slinfactory read_factory;                   /*!< Factory where frames read from the channel, or read from the whisper source will go through */
00085    struct ast_slinfactory write_factory;                  /*!< Factory where frames written to the channel will go through */
00086    struct timeval read_time;                              /*!< Last time read factory was fed */
00087    struct timeval write_time;                             /*!< Last time write factory was fed */
00088    int format;                                            /*!< Format translation path is setup as */
00089    struct ast_trans_pvt *trans_pvt;                       /*!< Translation path for reading frames */
00090    ast_audiohook_manipulate_callback manipulate_callback; /*!< Manipulation callback */
00091    struct ast_audiohook_options options;                  /*!< Applicable options */
00092    AST_LIST_ENTRY(ast_audiohook) list;                    /*!< Linked list information */
00093 };
00094 
00095 struct ast_audiohook_list;
00096 
00097 /*! \brief Initialize an audiohook structure
00098  * \param audiohook Audiohook structure
00099  * \param type Type of audiohook to initialize this as
00100  * \param source Who is initializing this audiohook
00101  * \return Returns 0 on success, -1 on failure
00102  */
00103 int ast_audiohook_init(struct ast_audiohook *audiohook, enum ast_audiohook_type type, const char *source);
00104 
00105 /*! \brief Destroys an audiohook structure
00106  * \param audiohook Audiohook structure
00107  * \return Returns 0 on success, -1 on failure
00108  */
00109 int ast_audiohook_destroy(struct ast_audiohook *audiohook);
00110 
00111 /*! \brief Writes a frame into the audiohook structure
00112  * \param audiohook Audiohook structure
00113  * \param direction Direction the audio frame came from
00114  * \param frame Frame to write in
00115  * \return Returns 0 on success, -1 on failure
00116  */
00117 int ast_audiohook_write_frame(struct ast_audiohook *audiohook, enum ast_audiohook_direction direction, struct ast_frame *frame);
00118 
00119 /*! \brief Reads a frame in from the audiohook structure
00120  * \param audiohook Audiohook structure
00121  * \param samples Number of samples wanted
00122  * \param direction Direction the audio frame came from
00123  * \param format Format of frame remote side wants back
00124  * \return Returns frame on success, NULL on failure
00125  */
00126 struct ast_frame *ast_audiohook_read_frame(struct ast_audiohook *audiohook, size_t samples, enum ast_audiohook_direction direction, int format);
00127 
00128 /*! \brief Attach audiohook to channel
00129  * \param chan Channel
00130  * \param audiohook Audiohook structure
00131  * \return Returns 0 on success, -1 on failure
00132  */
00133 int ast_audiohook_attach(struct ast_channel *chan, struct ast_audiohook *audiohook);
00134 
00135 /*! \brief Detach audiohook from channel
00136  * \param audiohook Audiohook structure
00137  * \return Returns 0 on success, -1 on failure
00138  */
00139 int ast_audiohook_detach(struct ast_audiohook *audiohook);
00140 
00141 /*! \brief Detach audiohooks from list and destroy said list
00142  * \param audiohook_list List of audiohooks
00143  * \return Returns 0 on success, -1 on failure
00144  */
00145 int ast_audiohook_detach_list(struct ast_audiohook_list *audiohook_list);
00146 
00147 /*! \brief Detach specified source audiohook from channel
00148  * \param chan Channel to detach from
00149  * \param source Name of source to detach
00150  * \return Returns 0 on success, -1 on failure
00151  */
00152 int ast_audiohook_detach_source(struct ast_channel *chan, const char *source);
00153 
00154 /*! \brief Pass a frame off to be handled by the audiohook core
00155  * \param chan Channel that the list is coming off of
00156  * \param audiohook_list List of audiohooks
00157  * \param direction Direction frame is coming in from
00158  * \param frame The frame itself
00159  * \return Return frame on success, NULL on failure
00160  */
00161 struct ast_frame *ast_audiohook_write_list(struct ast_channel *chan, struct ast_audiohook_list *audiohook_list, enum ast_audiohook_direction direction, struct ast_frame *frame);
00162 
00163 /*! \brief Wait for audiohook trigger to be triggered
00164  * \param audiohook Audiohook to wait on
00165  */
00166 void ast_audiohook_trigger_wait(struct ast_audiohook *audiohook);
00167 
00168 /*! \brief Lock an audiohook
00169  * \param ah Audiohook structure
00170  */
00171 #define ast_audiohook_lock(ah) ast_mutex_lock(&(ah)->lock)
00172 
00173 /*! \brief Unlock an audiohook
00174  * \param ah Audiohook structure
00175  */
00176 #define ast_audiohook_unlock(ah) ast_mutex_unlock(&(ah)->lock)
00177 
00178 #if defined(__cplusplus) || defined(c_plusplus)
00179 }
00180 #endif
00181 
00182 #endif /* _ASTERISK_AUDIOHOOK_H */

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