Tue Apr 28 22:50:00 2009

Asterisk developer's documentation


audiohook.h

Go to the documentation of this file.
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 #define AST_AUDIOHOOK_SYNC_TOLERANCE 100 /*< Tolerance in milliseconds for audiohooks synchronization */
00060 
00061 struct ast_audiohook;
00062 
00063 /*! \brief Callback function for manipulate audiohook type
00064  * \param audiohook Audiohook structure
00065  * \param chan Channel
00066  * \param frame Frame of audio to manipulate
00067  * \param direction Direction frame came from
00068  * \return Returns 0 on success, -1 on failure
00069  * \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
00070  *       via it's own method. An example would be datastores.
00071  */
00072 typedef int (*ast_audiohook_manipulate_callback)(struct ast_audiohook *audiohook, struct ast_channel *chan, struct ast_frame *frame, enum ast_audiohook_direction direction);
00073 
00074 struct ast_audiohook_options {
00075    int read_volume;  /*!< Volume adjustment on frames read from the channel the hook is on */
00076    int write_volume; /*!< Volume adjustment on frames written to the channel the hook is on */
00077 };
00078 
00079 struct ast_audiohook {
00080    ast_mutex_t lock;                                      /*!< Lock that protects the audiohook structure */
00081    ast_cond_t trigger;                                    /*!< Trigger condition (if enabled) */
00082    enum ast_audiohook_type type;                          /*!< Type of audiohook */
00083    enum ast_audiohook_status status;                      /*!< Status of the audiohook */
00084    const char *source;                                    /*!< Who this audiohook ultimately belongs to */
00085    unsigned int flags;                                    /*!< Flags on the audiohook */
00086    struct ast_slinfactory read_factory;                   /*!< Factory where frames read from the channel, or read from the whisper source will go through */
00087    struct ast_slinfactory write_factory;                  /*!< Factory where frames written to the channel will go through */
00088    struct timeval read_time;                              /*!< Last time read factory was fed */
00089    struct timeval write_time;                             /*!< Last time write factory was fed */
00090    int format;                                            /*!< Format translation path is setup as */
00091    struct ast_trans_pvt *trans_pvt;                       /*!< Translation path for reading frames */
00092    ast_audiohook_manipulate_callback manipulate_callback; /*!< Manipulation callback */
00093    struct ast_audiohook_options options;                  /*!< Applicable options */
00094    AST_LIST_ENTRY(ast_audiohook) list;                    /*!< Linked list information */
00095 };
00096 
00097 struct ast_audiohook_list;
00098 
00099 /*! \brief Initialize an audiohook structure
00100  * \param audiohook Audiohook structure
00101  * \param type Type of audiohook to initialize this as
00102  * \param source Who is initializing this audiohook
00103  * \return Returns 0 on success, -1 on failure
00104  */
00105 int ast_audiohook_init(struct ast_audiohook *audiohook, enum ast_audiohook_type type, const char *source);
00106 
00107 /*! \brief Destroys an audiohook structure
00108  * \param audiohook Audiohook structure
00109  * \return Returns 0 on success, -1 on failure
00110  */
00111 int ast_audiohook_destroy(struct ast_audiohook *audiohook);
00112 
00113 /*! \brief Writes a frame into the audiohook structure
00114  * \param audiohook Audiohook structure
00115  * \param direction Direction the audio frame came from
00116  * \param frame Frame to write in
00117  * \return Returns 0 on success, -1 on failure
00118  */
00119 int ast_audiohook_write_frame(struct ast_audiohook *audiohook, enum ast_audiohook_direction direction, struct ast_frame *frame);
00120 
00121 /*! \brief Reads a frame in from the audiohook structure
00122  * \param audiohook Audiohook structure
00123  * \param samples Number of samples wanted
00124  * \param direction Direction the audio frame came from
00125  * \param format Format of frame remote side wants back
00126  * \return Returns frame on success, NULL on failure
00127  */
00128 struct ast_frame *ast_audiohook_read_frame(struct ast_audiohook *audiohook, size_t samples, enum ast_audiohook_direction direction, int format);
00129 
00130 /*! \brief Attach audiohook to channel
00131  * \param chan Channel
00132  * \param audiohook Audiohook structure
00133  * \return Returns 0 on success, -1 on failure
00134  */
00135 int ast_audiohook_attach(struct ast_channel *chan, struct ast_audiohook *audiohook);
00136 
00137 /*! \brief Detach audiohook from channel
00138  * \param audiohook Audiohook structure
00139  * \return Returns 0 on success, -1 on failure
00140  */
00141 int ast_audiohook_detach(struct ast_audiohook *audiohook);
00142 
00143 /*! \brief Detach audiohooks from list and destroy said list
00144  * \param audiohook_list List of audiohooks
00145  * \return Returns 0 on success, -1 on failure
00146  */
00147 int ast_audiohook_detach_list(struct ast_audiohook_list *audiohook_list);
00148 
00149 /*! \brief Move an audiohook from one channel to a new one
00150  *
00151  * \todo Currently only the first audiohook of a specific source found will be moved.
00152  * We should add the capability to move multiple audiohooks from a single source as well.
00153  *
00154  * \note It is required that both old_chan and new_chan are locked prior to calling
00155  * this function. Besides needing to protect the data within the channels, not locking
00156  * these channels can lead to a potential deadlock
00157  *
00158  * \param old_chan The source of the audiohook to move
00159  * \param new_chan The destination to which we want the audiohook to move
00160  * \param source The source of the audiohook we want to move
00161  */
00162 void ast_audiohook_move_by_source(struct ast_channel *old_chan, struct ast_channel *new_chan, const char *source);
00163 
00164 /*! \brief Detach specified source audiohook from channel
00165  * \param chan Channel to detach from
00166  * \param source Name of source to detach
00167  * \return Returns 0 on success, -1 on failure
00168  */
00169 int ast_audiohook_detach_source(struct ast_channel *chan, const char *source);
00170 
00171 /*!
00172  * \brief Remove an audiohook from a specified channel
00173  *
00174  * \param chan Channel to remove from
00175  * \param audiohook Audiohook to remove
00176  *
00177  * \return Returns 0 on success, -1 on failure
00178  *
00179  * \note The channel does not need to be locked before calling this function
00180  */
00181 int ast_audiohook_remove(struct ast_channel *chan, struct ast_audiohook *audiohook);
00182 
00183 /*! \brief Pass a frame off to be handled by the audiohook core
00184  * \param chan Channel that the list is coming off of
00185  * \param audiohook_list List of audiohooks
00186  * \param direction Direction frame is coming in from
00187  * \param frame The frame itself
00188  * \return Return frame on success, NULL on failure
00189  */
00190 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);
00191 
00192 /*! \brief Wait for audiohook trigger to be triggered
00193  * \param audiohook Audiohook to wait on
00194  */
00195 void ast_audiohook_trigger_wait(struct ast_audiohook *audiohook);
00196 
00197 /*! \brief Lock an audiohook
00198  * \param ah Audiohook structure
00199  */
00200 #define ast_audiohook_lock(ah) ast_mutex_lock(&(ah)->lock)
00201 
00202 /*! \brief Unlock an audiohook
00203  * \param ah Audiohook structure
00204  */
00205 #define ast_audiohook_unlock(ah) ast_mutex_unlock(&(ah)->lock)
00206 
00207 #if defined(__cplusplus) || defined(c_plusplus)
00208 }
00209 #endif
00210 
00211 #endif /* _ASTERISK_AUDIOHOOK_H */

Generated on Tue Apr 28 22:50:01 2009 for Asterisk - the Open Source PBX by  doxygen 1.4.7