Mon Jun 27 16:50:49 2011

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 /* these two are used in struct ast_audiohook */
00031 #include "asterisk/lock.h"
00032 #include "asterisk/linkedlists.h"
00033 #include "asterisk/frame_defs.h"
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    AST_AUDIOHOOK_MUTE_READ = (1 << 4),     /*!< audiohook should be mute frames read */
00066    AST_AUDIOHOOK_MUTE_WRITE = (1 << 5),    /*!< audiohook should be mute frames written */
00067 };
00068 
00069 #define AST_AUDIOHOOK_SYNC_TOLERANCE 100 /*< Tolerance in milliseconds for audiohooks synchronization */
00070 
00071 struct ast_audiohook;
00072 
00073 /*! \brief Callback function for manipulate audiohook type
00074  * \param audiohook Audiohook structure
00075  * \param chan Channel
00076  * \param frame Frame of audio to manipulate
00077  * \param direction Direction frame came from
00078  * \return Returns 0 on success, -1 on failure.
00079  * \note An audiohook does not have any reference to a private data structure for manipulate
00080  *       types. It is up to the manipulate callback to store this data via it's own method.
00081  *       An example would be datastores.
00082  * \note The input frame should never be freed or corrupted during a manipulate callback.
00083  *       If the callback has the potential to corrupt the frame's data during manipulation,
00084  *       local data should be used for the manipulation and only copied to the frame on
00085  *       success.
00086  * \note A failure return value indicates that the frame was not manipulated and that
00087  *       is being returned in its original state.
00088  */
00089 typedef int (*ast_audiohook_manipulate_callback)(struct ast_audiohook *audiohook, struct ast_channel *chan, struct ast_frame *frame, enum ast_audiohook_direction direction);
00090 
00091 struct ast_audiohook_options {
00092    int read_volume;  /*!< Volume adjustment on frames read from the channel the hook is on */
00093    int write_volume; /*!< Volume adjustment on frames written to the channel the hook is on */
00094 };
00095 
00096 struct ast_audiohook {
00097    ast_mutex_t lock;                                      /*!< Lock that protects the audiohook structure */
00098    ast_cond_t trigger;                                    /*!< Trigger condition (if enabled) */
00099    enum ast_audiohook_type type;                          /*!< Type of audiohook */
00100    enum ast_audiohook_status status;                      /*!< Status of the audiohook */
00101    const char *source;                                    /*!< Who this audiohook ultimately belongs to */
00102    unsigned int flags;                                    /*!< Flags on the audiohook */
00103    struct ast_slinfactory read_factory;                   /*!< Factory where frames read from the channel, or read from the whisper source will go through */
00104    struct ast_slinfactory write_factory;                  /*!< Factory where frames written to the channel will go through */
00105    struct timeval read_time;                              /*!< Last time read factory was fed */
00106    struct timeval write_time;                             /*!< Last time write factory was fed */
00107    int format;                                            /*!< Format translation path is setup as */
00108    struct ast_trans_pvt *trans_pvt;                       /*!< Translation path for reading frames */
00109    ast_audiohook_manipulate_callback manipulate_callback; /*!< Manipulation callback */
00110    struct ast_audiohook_options options;                  /*!< Applicable options */
00111    AST_LIST_ENTRY(ast_audiohook) list;                    /*!< Linked list information */
00112 };
00113 
00114 struct ast_audiohook_list;
00115 
00116 /*! \brief Initialize an audiohook structure
00117  * \param audiohook Audiohook structure
00118  * \param type Type of audiohook to initialize this as
00119  * \param source Who is initializing this audiohook
00120  * \return Returns 0 on success, -1 on failure
00121  */
00122 int ast_audiohook_init(struct ast_audiohook *audiohook, enum ast_audiohook_type type, const char *source);
00123 
00124 /*! \brief Destroys an audiohook structure
00125  * \param audiohook Audiohook structure
00126  * \return Returns 0 on success, -1 on failure
00127  */
00128 int ast_audiohook_destroy(struct ast_audiohook *audiohook);
00129 
00130 /*! \brief Writes a frame into the audiohook structure
00131  * \param audiohook Audiohook structure
00132  * \param direction Direction the audio frame came from
00133  * \param frame Frame to write in
00134  * \return Returns 0 on success, -1 on failure
00135  */
00136 int ast_audiohook_write_frame(struct ast_audiohook *audiohook, enum ast_audiohook_direction direction, struct ast_frame *frame);
00137 
00138 /*! \brief Reads a frame in from the audiohook structure
00139  * \param audiohook Audiohook structure
00140  * \param samples Number of samples wanted
00141  * \param direction Direction the audio frame came from
00142  * \param format Format of frame remote side wants back
00143  * \return Returns frame on success, NULL on failure
00144  */
00145 struct ast_frame *ast_audiohook_read_frame(struct ast_audiohook *audiohook, size_t samples, enum ast_audiohook_direction direction, format_t format);
00146 
00147 /*! \brief Attach audiohook to channel
00148  * \param chan Channel
00149  * \param audiohook Audiohook structure
00150  * \return Returns 0 on success, -1 on failure
00151  */
00152 int ast_audiohook_attach(struct ast_channel *chan, struct ast_audiohook *audiohook);
00153 
00154 /*! \brief Detach audiohook from channel
00155  * \param audiohook Audiohook structure
00156  * \return Returns 0 on success, -1 on failure
00157  */
00158 int ast_audiohook_detach(struct ast_audiohook *audiohook);
00159 
00160 /*! \brief Detach audiohooks from list and destroy said list
00161  * \param audiohook_list List of audiohooks
00162  * \return Returns 0 on success, -1 on failure
00163  */
00164 int ast_audiohook_detach_list(struct ast_audiohook_list *audiohook_list);
00165 
00166 /*! \brief Move an audiohook from one channel to a new one
00167  *
00168  * \todo Currently only the first audiohook of a specific source found will be moved.
00169  * We should add the capability to move multiple audiohooks from a single source as well.
00170  *
00171  * \note It is required that both old_chan and new_chan are locked prior to calling
00172  * this function. Besides needing to protect the data within the channels, not locking
00173  * these channels can lead to a potential deadlock
00174  *
00175  * \param old_chan The source of the audiohook to move
00176  * \param new_chan The destination to which we want the audiohook to move
00177  * \param source The source of the audiohook we want to move
00178  */
00179 void ast_audiohook_move_by_source(struct ast_channel *old_chan, struct ast_channel *new_chan, const char *source);
00180 
00181 /*!
00182  * \brief Detach specified source audiohook from channel
00183  *
00184  * \param chan Channel to detach from
00185  * \param source Name of source to detach
00186  *
00187  * \return Returns 0 on success, -1 on failure
00188  *
00189  * \note The channel does not need to be locked before calling this function.
00190  */
00191 int ast_audiohook_detach_source(struct ast_channel *chan, const char *source);
00192 
00193 /*!
00194  * \brief Remove an audiohook from a specified channel
00195  *
00196  * \param chan Channel to remove from
00197  * \param audiohook Audiohook to remove
00198  *
00199  * \return Returns 0 on success, -1 on failure
00200  *
00201  * \note The channel does not need to be locked before calling this function
00202  */
00203 int ast_audiohook_remove(struct ast_channel *chan, struct ast_audiohook *audiohook);
00204 
00205 /*!
00206  * \brief determines if a audiohook_list is empty or not.
00207  *
00208  * retval 0 false, 1 true
00209  */
00210 int ast_audiohook_write_list_empty(struct ast_audiohook_list *audiohook_list);
00211 
00212 /*! \brief Pass a frame off to be handled by the audiohook core
00213  * \param chan Channel that the list is coming off of
00214  * \param audiohook_list List of audiohooks
00215  * \param direction Direction frame is coming in from
00216  * \param frame The frame itself
00217  * \return Return frame on success, NULL on failure
00218  */
00219 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);
00220 
00221 /*! \brief Update audiohook's status
00222  * \param audiohook Audiohook structure
00223  * \param audiohook status enum
00224  *
00225  * \note once status is updated to DONE, this function can not be used to set the
00226  * status back to any other setting.  Setting DONE effectively locks the status as such.
00227  */
00228 void ast_audiohook_update_status(struct ast_audiohook *audiohook, enum ast_audiohook_status status);
00229 
00230 /*! \brief Wait for audiohook trigger to be triggered
00231  * \param audiohook Audiohook to wait on
00232  */
00233 void ast_audiohook_trigger_wait(struct ast_audiohook *audiohook);
00234 
00235 /*!
00236   \brief Find out how many audiohooks from  a certain source exist on a given channel, regardless of status.
00237   \param chan The channel on which to find the spies
00238   \param source The audiohook's source
00239   \param type The type of audiohook
00240   \return Return the number of audiohooks which are from the source specified
00241 
00242   Note: Function performs nlocking.
00243 */
00244 int ast_channel_audiohook_count_by_source(struct ast_channel *chan, const char *source, enum ast_audiohook_type type);
00245 
00246 /*!
00247   \brief Find out how many spies of a certain type exist on a given channel, and are in state running.
00248   \param chan The channel on which to find the spies
00249   \param source The source of the audiohook
00250   \param type The type of spy to look for
00251   \return Return the number of running audiohooks which are from the source specified
00252 
00253   Note: Function performs no locking.
00254 */
00255 int ast_channel_audiohook_count_by_source_running(struct ast_channel *chan, const char *source, enum ast_audiohook_type type);
00256 
00257 /*! \brief Lock an audiohook
00258  * \param ah Audiohook structure
00259  */
00260 #define ast_audiohook_lock(ah) ast_mutex_lock(&(ah)->lock)
00261 
00262 /*! \brief Unlock an audiohook
00263  * \param ah Audiohook structure
00264  */
00265 #define ast_audiohook_unlock(ah) ast_mutex_unlock(&(ah)->lock)
00266 
00267 /*!
00268  * \brief Adjust the volume on frames read from or written to a channel
00269  * \param chan Channel to muck with
00270  * \param direction Direction to set on
00271  * \param volume Value to adjust the volume by
00272  * \return Returns 0 on success, -1 on failure
00273  * \since 1.6.1
00274  */
00275 int ast_audiohook_volume_set(struct ast_channel *chan, enum ast_audiohook_direction direction, int volume);
00276 
00277 /*!
00278  * \brief Retrieve the volume adjustment value on frames read from or written to a channel
00279  * \param chan Channel to retrieve volume adjustment from
00280  * \param direction Direction to retrieve
00281  * \return Returns adjustment value
00282  * \since 1.6.1
00283  */
00284 int ast_audiohook_volume_get(struct ast_channel *chan, enum ast_audiohook_direction direction);
00285 
00286 /*!
00287  * \brief Adjust the volume on frames read from or written to a channel
00288  * \param chan Channel to muck with
00289  * \param direction Direction to increase
00290  * \param volume Value to adjust the adjustment by
00291  * \return Returns 0 on success, -1 on failure
00292  * \since 1.6.1
00293  */
00294 int ast_audiohook_volume_adjust(struct ast_channel *chan, enum ast_audiohook_direction direction, int volume);
00295 
00296 /*! \brief Mute frames read from or written to a channel
00297  * \param chan Channel to muck with
00298  * \param source Type of audiohook
00299  * \param flag which direction to set / clear
00300  * \param clear set or clear muted frames on direction based on flag parameter
00301  * \retval 0 success
00302  * \retval -1 failure
00303  */
00304 int ast_audiohook_set_mute(struct ast_channel *chan, const char *source, enum ast_audiohook_flags flag, int clear);
00305 
00306 #if defined(__cplusplus) || defined(c_plusplus)
00307 }
00308 #endif
00309 
00310 #endif /* _ASTERISK_AUDIOHOOK_H */

Generated on Mon Jun 27 16:50:49 2011 for Asterisk - The Open Source Telephony Project by  doxygen 1.4.7