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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 /* these two are used in struct ast_audiohook */
00031 #include "asterisk/lock.h"
00032 #include "asterisk/linkedlists.h"
00033 
00034 #include "asterisk/slinfactory.h"
00035 
00036 enum ast_audiohook_type {
00037    AST_AUDIOHOOK_TYPE_SPY = 0,    /*!< Audiohook wants to receive audio */
00038    AST_AUDIOHOOK_TYPE_WHISPER,    /*!< Audiohook wants to provide audio to be mixed with existing audio */
00039    AST_AUDIOHOOK_TYPE_MANIPULATE, /*!< Audiohook wants to manipulate the audio */
00040 };
00041 
00042 enum ast_audiohook_status {
00043    AST_AUDIOHOOK_STATUS_NEW = 0,  /*!< Audiohook was just created, not in use yet */
00044    AST_AUDIOHOOK_STATUS_RUNNING,  /*!< Audiohook is running on a channel */
00045    AST_AUDIOHOOK_STATUS_SHUTDOWN, /*!< Audiohook is being shutdown */
00046    AST_AUDIOHOOK_STATUS_DONE,     /*!< Audiohook has shutdown and is not running on a channel any longer */
00047 };
00048 
00049 enum ast_audiohook_direction {
00050    AST_AUDIOHOOK_DIRECTION_READ = 0, /*!< Reading audio in */
00051    AST_AUDIOHOOK_DIRECTION_WRITE,    /*!< Writing audio out */
00052    AST_AUDIOHOOK_DIRECTION_BOTH,     /*!< Both reading audio in and writing audio out */
00053 };
00054 
00055 enum ast_audiohook_flags {
00056    AST_AUDIOHOOK_TRIGGER_MODE = (3 << 0),  /*!< When audiohook should be triggered to do something */
00057    AST_AUDIOHOOK_TRIGGER_READ = (1 << 0),  /*!< Audiohook wants to be triggered when reading audio in */
00058    AST_AUDIOHOOK_TRIGGER_WRITE = (2 << 0), /*!< Audiohook wants to be triggered when writing audio out */
00059    AST_AUDIOHOOK_WANTS_DTMF = (1 << 1),    /*!< Audiohook also wants to receive DTMF frames */
00060    AST_AUDIOHOOK_TRIGGER_SYNC = (1 << 2),  /*!< Audiohook wants to be triggered when both sides have combined audio available */
00061    /*! Audiohooks with this flag set will not allow for a large amount of samples to build up on its
00062     * slinfactories. We will flush the factories if they contain too many samples.
00063     */
00064    AST_AUDIOHOOK_SMALL_QUEUE = (1 << 3),
00065 };
00066 
00067 #define AST_AUDIOHOOK_SYNC_TOLERANCE 100 /*< Tolerance in milliseconds for audiohooks synchronization */
00068 
00069 struct ast_audiohook;
00070 
00071 /*! \brief Callback function for manipulate audiohook type
00072  * \param audiohook Audiohook structure
00073  * \param chan Channel
00074  * \param frame Frame of audio to manipulate
00075  * \param direction Direction frame came from
00076  * \return Returns 0 on success, -1 on failure.
00077  * \note An audiohook does not have any reference to a private data structure for manipulate
00078  *       types. It is up to the manipulate callback to store this data via it's own method.
00079  *       An example would be datastores.
00080  * \note The input frame should never be freed or corrupted during a manipulate callback.
00081  *       If the callback has the potential to corrupt the frame's data during manipulation,
00082  *       local data should be used for the manipulation and only copied to the frame on
00083  *       success.
00084  * \note A failure return value indicates that the frame was not manipulated and that
00085  *       is being returned in its original state.
00086  */
00087 typedef int (*ast_audiohook_manipulate_callback)(struct ast_audiohook *audiohook, struct ast_channel *chan, struct ast_frame *frame, enum ast_audiohook_direction direction);
00088 
00089 struct ast_audiohook_options {
00090    int read_volume;  /*!< Volume adjustment on frames read from the channel the hook is on */
00091    int write_volume; /*!< Volume adjustment on frames written to the channel the hook is on */
00092 };
00093 
00094 struct ast_audiohook {
00095    ast_mutex_t lock;                                      /*!< Lock that protects the audiohook structure */
00096    ast_cond_t trigger;                                    /*!< Trigger condition (if enabled) */
00097    enum ast_audiohook_type type;                          /*!< Type of audiohook */
00098    enum ast_audiohook_status status;                      /*!< Status of the audiohook */
00099    const char *source;                                    /*!< Who this audiohook ultimately belongs to */
00100    unsigned int flags;                                    /*!< Flags on the audiohook */
00101    struct ast_slinfactory read_factory;                   /*!< Factory where frames read from the channel, or read from the whisper source will go through */
00102    struct ast_slinfactory write_factory;                  /*!< Factory where frames written to the channel will go through */
00103    struct timeval read_time;                              /*!< Last time read factory was fed */
00104    struct timeval write_time;                             /*!< Last time write factory was fed */
00105    int format;                                            /*!< Format translation path is setup as */
00106    struct ast_trans_pvt *trans_pvt;                       /*!< Translation path for reading frames */
00107    ast_audiohook_manipulate_callback manipulate_callback; /*!< Manipulation callback */
00108    struct ast_audiohook_options options;                  /*!< Applicable options */
00109    AST_LIST_ENTRY(ast_audiohook) list;                    /*!< Linked list information */
00110 };
00111 
00112 struct ast_audiohook_list;
00113 
00114 /*! \brief Initialize an audiohook structure
00115  * \param audiohook Audiohook structure
00116  * \param type Type of audiohook to initialize this as
00117  * \param source Who is initializing this audiohook
00118  * \return Returns 0 on success, -1 on failure
00119  */
00120 int ast_audiohook_init(struct ast_audiohook *audiohook, enum ast_audiohook_type type, const char *source);
00121 
00122 /*! \brief Destroys an audiohook structure
00123  * \param audiohook Audiohook structure
00124  * \return Returns 0 on success, -1 on failure
00125  */
00126 int ast_audiohook_destroy(struct ast_audiohook *audiohook);
00127 
00128 /*! \brief Writes a frame into the audiohook structure
00129  * \param audiohook Audiohook structure
00130  * \param direction Direction the audio frame came from
00131  * \param frame Frame to write in
00132  * \return Returns 0 on success, -1 on failure
00133  */
00134 int ast_audiohook_write_frame(struct ast_audiohook *audiohook, enum ast_audiohook_direction direction, struct ast_frame *frame);
00135 
00136 /*! \brief Reads a frame in from the audiohook structure
00137  * \param audiohook Audiohook structure
00138  * \param samples Number of samples wanted
00139  * \param direction Direction the audio frame came from
00140  * \param format Format of frame remote side wants back
00141  * \return Returns frame on success, NULL on failure
00142  */
00143 struct ast_frame *ast_audiohook_read_frame(struct ast_audiohook *audiohook, size_t samples, enum ast_audiohook_direction direction, int format);
00144 
00145 /*! \brief Attach audiohook to channel
00146  * \param chan Channel
00147  * \param audiohook Audiohook structure
00148  * \return Returns 0 on success, -1 on failure
00149  */
00150 int ast_audiohook_attach(struct ast_channel *chan, struct ast_audiohook *audiohook);
00151 
00152 /*! \brief Detach audiohook from channel
00153  * \param audiohook Audiohook structure
00154  * \return Returns 0 on success, -1 on failure
00155  */
00156 int ast_audiohook_detach(struct ast_audiohook *audiohook);
00157 
00158 /*! \brief Detach audiohooks from list and destroy said list
00159  * \param audiohook_list List of audiohooks
00160  * \return Returns 0 on success, -1 on failure
00161  */
00162 int ast_audiohook_detach_list(struct ast_audiohook_list *audiohook_list);
00163 
00164 /*! \brief Move an audiohook from one channel to a new one
00165  *
00166  * \todo Currently only the first audiohook of a specific source found will be moved.
00167  * We should add the capability to move multiple audiohooks from a single source as well.
00168  *
00169  * \note It is required that both old_chan and new_chan are locked prior to calling
00170  * this function. Besides needing to protect the data within the channels, not locking
00171  * these channels can lead to a potential deadlock
00172  *
00173  * \param old_chan The source of the audiohook to move
00174  * \param new_chan The destination to which we want the audiohook to move
00175  * \param source The source of the audiohook we want to move
00176  */
00177 void ast_audiohook_move_by_source(struct ast_channel *old_chan, struct ast_channel *new_chan, const char *source);
00178 
00179 /*!
00180  * \brief Detach specified source audiohook from channel
00181  *
00182  * \param chan Channel to detach from
00183  * \param source Name of source to detach
00184  *
00185  * \return Returns 0 on success, -1 on failure
00186  *
00187  * \note The channel does not need to be locked before calling this function.
00188  */
00189 int ast_audiohook_detach_source(struct ast_channel *chan, const char *source);
00190 
00191 /*!
00192  * \brief Remove an audiohook from a specified channel
00193  *
00194  * \param chan Channel to remove from
00195  * \param audiohook Audiohook to remove
00196  *
00197  * \return Returns 0 on success, -1 on failure
00198  *
00199  * \note The channel does not need to be locked before calling this function
00200  */
00201 int ast_audiohook_remove(struct ast_channel *chan, struct ast_audiohook *audiohook);
00202 
00203 /*!
00204  * \brief determines if a audiohook_list is empty or not.
00205  *
00206  * retval 0 false, 1 true
00207  */
00208 int ast_audiohook_write_list_empty(struct ast_audiohook_list *audiohook_list);
00209 
00210 /*! \brief Pass a frame off to be handled by the audiohook core
00211  * \param chan Channel that the list is coming off of
00212  * \param audiohook_list List of audiohooks
00213  * \param direction Direction frame is coming in from
00214  * \param frame The frame itself
00215  * \return Return frame on success, NULL on failure
00216  */
00217 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);
00218 
00219 /*! \brief Update audiohook's status
00220  * \param audiohook Audiohook structure
00221  * \param audiohook status enum
00222  *
00223  * \note once status is updated to DONE, this function can not be used to set the
00224  * status back to any other setting.  Setting DONE effectively locks the status as such.
00225  */
00226 void ast_audiohook_update_status(struct ast_audiohook *audiohook, enum ast_audiohook_status status);
00227 
00228 /*! \brief Wait for audiohook trigger to be triggered
00229  * \param audiohook Audiohook to wait on
00230  */
00231 void ast_audiohook_trigger_wait(struct ast_audiohook *audiohook);
00232 
00233 /*!
00234   \brief Find out how many audiohooks from  a certain source exist on a given channel, regardless of status.
00235   \param chan The channel on which to find the spies
00236   \param source The audiohook's source
00237   \param type The type of audiohook
00238   \return Return the number of audiohooks which are from the source specified
00239 
00240   Note: Function performs nlocking.
00241 */
00242 int ast_channel_audiohook_count_by_source(struct ast_channel *chan, const char *source, enum ast_audiohook_type type);
00243 
00244 /*!
00245   \brief Find out how many spies of a certain type exist on a given channel, and are in state running.
00246   \param chan The channel on which to find the spies
00247   \param source The source of the audiohook
00248   \param type The type of spy to look for
00249   \return Return the number of running audiohooks which are from the source specified
00250 
00251   Note: Function performs no locking.
00252 */
00253 int ast_channel_audiohook_count_by_source_running(struct ast_channel *chan, const char *source, enum ast_audiohook_type type);
00254 
00255 /*! \brief Lock an audiohook
00256  * \param ah Audiohook structure
00257  */
00258 #define ast_audiohook_lock(ah) ast_mutex_lock(&(ah)->lock)
00259 
00260 /*! \brief Unlock an audiohook
00261  * \param ah Audiohook structure
00262  */
00263 #define ast_audiohook_unlock(ah) ast_mutex_unlock(&(ah)->lock)
00264 
00265 /*!
00266  * \brief Adjust the volume on frames read from or written to a channel
00267  * \param chan Channel to muck with
00268  * \param direction Direction to set on
00269  * \param volume Value to adjust the volume by
00270  * \return Returns 0 on success, -1 on failure
00271  * \since 1.6.1
00272  */
00273 int ast_audiohook_volume_set(struct ast_channel *chan, enum ast_audiohook_direction direction, int volume);
00274 
00275 /*!
00276  * \brief Retrieve the volume adjustment value on frames read from or written to a channel
00277  * \param chan Channel to retrieve volume adjustment from
00278  * \param direction Direction to retrieve
00279  * \return Returns adjustment value
00280  * \since 1.6.1
00281  */
00282 int ast_audiohook_volume_get(struct ast_channel *chan, enum ast_audiohook_direction direction);
00283 
00284 /*!
00285  * \brief Adjust the volume on frames read from or written to a channel
00286  * \param chan Channel to muck with
00287  * \param direction Direction to increase
00288  * \param volume Value to adjust the adjustment by
00289  * \return Returns 0 on success, -1 on failure
00290  * \since 1.6.1
00291  */
00292 int ast_audiohook_volume_adjust(struct ast_channel *chan, enum ast_audiohook_direction direction, int volume);
00293 
00294 #if defined(__cplusplus) || defined(c_plusplus)
00295 }
00296 #endif
00297 
00298 #endif /* _ASTERISK_AUDIOHOOK_H */