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Diffstat (limited to '1.4.23-rc4/include/asterisk/abstract_jb.h')
| -rw-r--r-- | 1.4.23-rc4/include/asterisk/abstract_jb.h | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/1.4.23-rc4/include/asterisk/abstract_jb.h b/1.4.23-rc4/include/asterisk/abstract_jb.h new file mode 100644 index 000000000..820e87cea --- /dev/null +++ b/1.4.23-rc4/include/asterisk/abstract_jb.h @@ -0,0 +1,226 @@ +/* + * abstract_jb: common implementation-independent jitterbuffer stuff + * + * Copyright (C) 2005, Attractel OOD + * + * Contributors: + * Slav Klenov <slav@securax.org> + * + * See http://www.asterisk.org for more information about + * the Asterisk project. Please do not directly contact + * any of the maintainers of this project for assistance; + * the project provides a web site, mailing lists and IRC + * channels for your use. + * + * This program is free software, distributed under the terms of + * the GNU General Public License Version 2. See the LICENSE file + * at the top of the source tree. + * + * A license has been granted to Digium (via disclaimer) for the use of + * this code. + */ + +/*! \file + * + * \brief Common implementation-independent jitterbuffer stuff. + * + * \author Slav Klenov <slav@securax.org> + */ + +#ifndef _ABSTRACT_JB_H_ +#define _ABSTRACT_JB_H_ + +#include <stdio.h> +#include <sys/time.h> + +#if defined(__cplusplus) || defined(c_plusplus) +extern "C" { +#endif + +struct ast_channel; +struct ast_frame; + +/* Configuration flags */ +enum { + AST_JB_ENABLED = (1 << 0), + AST_JB_FORCED = (1 << 1), + AST_JB_LOG = (1 << 2) +}; + +#define AST_JB_IMPL_NAME_SIZE 12 + +/*! + * \brief General jitterbuffer configuration. + */ +struct ast_jb_conf +{ + /*! \brief Combination of the AST_JB_ENABLED, AST_JB_FORCED and AST_JB_LOG flags. */ + unsigned int flags; + /*! \brief Max size of the jitterbuffer implementation. */ + long max_size; + /*! \brief Resynchronization threshold of the jitterbuffer implementation. */ + long resync_threshold; + /*! \brief Name of the jitterbuffer implementation to be used. */ + char impl[AST_JB_IMPL_NAME_SIZE]; +}; + + +/* Jitterbuffer configuration property names */ +#define AST_JB_CONF_PREFIX "jb" +#define AST_JB_CONF_ENABLE "enable" +#define AST_JB_CONF_FORCE "force" +#define AST_JB_CONF_MAX_SIZE "maxsize" +#define AST_JB_CONF_RESYNCH_THRESHOLD "resyncthreshold" +#define AST_JB_CONF_IMPL "impl" +#define AST_JB_CONF_LOG "log" + + +struct ast_jb_impl; + + +/*! + * \brief General jitterbuffer state. + */ +struct ast_jb +{ + /*! \brief Jitterbuffer configuration. */ + struct ast_jb_conf conf; + /*! \brief Jitterbuffer implementation to be used. */ + struct ast_jb_impl *impl; + /*! \brief Jitterbuffer object, passed to the implementation. */ + void *jbobj; + /*! \brief The time the jitterbuffer was created. */ + struct timeval timebase; + /*! \brief The time the next frame should be played. */ + long next; + /*! \brief Voice format of the last frame in. */ + int last_format; + /*! \brief File for frame timestamp tracing. */ + FILE *logfile; + /*! \brief Jitterbuffer internal state flags. */ + unsigned int flags; +}; + + +/*! + * \brief Checks the need of a jb use in a generic bridge. + * \param c0 first bridged channel. + * \param c1 second bridged channel. + * + * Called from ast_generic_bridge() when two channels are entering in a bridge. + * The function checks the need of a jitterbuffer, depending on both channel's + * configuration and technology properties. As a result, this function sets + * appropriate internal jb flags to the channels, determining further behaviour + * of the bridged jitterbuffers. + * + * \return zero if there are no jitter buffers in use, non-zero if there are + */ +int ast_jb_do_usecheck(struct ast_channel *c0, struct ast_channel *c1); + + +/*! + * \brief Calculates the time, left to the closest delivery moment in a bridge. + * \param c0 first bridged channel. + * \param c1 second bridged channel. + * \param time_left bridge time limit, or -1 if not set. + * + * Called from ast_generic_bridge() to determine the maximum time to wait for + * activity in ast_waitfor_n() call. If neihter of the channels is using jb, + * this function returns the time limit passed. + * + * \return maximum time to wait. + */ +int ast_jb_get_when_to_wakeup(struct ast_channel *c0, struct ast_channel *c1, int time_left); + + +/*! + * \brief Puts a frame into a channel jitterbuffer. + * \param chan channel. + * \param f frame. + * + * Called from ast_generic_bridge() to put a frame into a channel's jitterbuffer. + * The function will successfuly enqueue a frame if and only if: + * 1. the channel is using a jitterbuffer (as determined by ast_jb_do_usecheck()), + * 2. the frame's type is AST_FRAME_VOICE, + * 3. the frame has timing info set and has length >= 2 ms, + * 4. there is no some internal error happened (like failed memory allocation). + * Frames, successfuly queued, should be delivered by the channel's jitterbuffer, + * when their delivery time has came. + * Frames, not successfuly queued, should be delivered immediately. + * Dropped by the jb implementation frames are considered successfuly enqueued as + * far as they should not be delivered at all. + * + * \return zero if the frame was queued, -1 if not. + */ +int ast_jb_put(struct ast_channel *chan, struct ast_frame *f); + + +/*! + * \brief Deliver the queued frames that should be delivered now for both channels. + * \param c0 first bridged channel. + * \param c1 second bridged channel. + * + * Called from ast_generic_bridge() to deliver any frames, that should be delivered + * for the moment of invocation. Does nothing if neihter of the channels is using jb + * or has any frames currently queued in. The function delivers frames usig ast_write() + * each of the channels. + */ +void ast_jb_get_and_deliver(struct ast_channel *c0, struct ast_channel *c1); + + +/*! + * \brief Destroys jitterbuffer on a channel. + * \param chan channel. + * + * Called from ast_channel_free() when a channel is destroyed. + */ +void ast_jb_destroy(struct ast_channel *chan); + + +/*! + * \brief Sets jitterbuffer configuration property. + * \param conf configuration to store the property in. + * \param varname property name. + * \param value property value. + * + * Called from a channel driver to build a jitterbuffer configuration tipically when + * reading a configuration file. It is not neccessary for a channel driver to know + * each of the jb configuration property names. The jitterbuffer itself knows them. + * The channel driver can pass each config var it reads through this function. It will + * return 0 if the variable was consumed from the jb conf. + * + * \return zero if the property was set to the configuration, -1 if not. + */ +int ast_jb_read_conf(struct ast_jb_conf *conf, char *varname, char *value); + + +/*! + * \brief Configures a jitterbuffer on a channel. + * \param chan channel to configure. + * \param conf configuration to apply. + * + * Called from a channel driver when a channel is created and its jitterbuffer needs + * to be configured. + */ +void ast_jb_configure(struct ast_channel *chan, const struct ast_jb_conf *conf); + + +/*! + * \brief Copies a channel's jitterbuffer configuration. + * \param chan channel. + * \param conf destination. + */ +void ast_jb_get_config(const struct ast_channel *chan, struct ast_jb_conf *conf); + +/*! + * \brief drops all frames from a jitterbuffer and resets it + * \param c0 one channel of a bridge + * \param c1 the other channel of the bridge + */ +void ast_jb_empty_and_reset(struct ast_channel *c0, struct ast_channel *c1); + +#if defined(__cplusplus) || defined(c_plusplus) +} +#endif + +#endif /* _ABSTRACT_JB_H_ */ |