abstract_jb.h File Reference

Common implementation-independent jitterbuffer stuff. More...

#include <sys/time.h>

Include dependency graph for abstract_jb.h:

This graph shows which files directly or indirectly include this file:

Data Structures
struct	ast_jb
	General jitterbuffer state. More...
struct	ast_jb_conf
	General jitterbuffer configuration. More...
Defines
#define	AST_JB_CONF_ENABLE "enable"
#define	AST_JB_CONF_FORCE "force"
#define	AST_JB_CONF_IMPL "impl"
#define	AST_JB_CONF_LOG "log"
#define	AST_JB_CONF_MAX_SIZE "maxsize"
#define	AST_JB_CONF_PREFIX "jb"
#define	AST_JB_CONF_RESYNCH_THRESHOLD "resyncthreshold"
#define	AST_JB_IMPL_NAME_SIZE 12
Enumerations
enum	{ AST_JB_ENABLED = (1 << 0), AST_JB_FORCED = (1 << 1), AST_JB_LOG = (1 << 2) }
Functions
void	ast_jb_configure (struct ast_channel chan, const struct ast_jb_conf conf)
	Configures a jitterbuffer on a channel.
void	ast_jb_destroy (struct ast_channel *chan)
	Destroys jitterbuffer on a channel.
int	ast_jb_do_usecheck (struct ast_channel c0, struct ast_channel c1)
	Checks the need of a jb use in a generic bridge.
void	ast_jb_empty_and_reset (struct ast_channel c0, struct ast_channel c1)
	drops all frames from a jitterbuffer and resets it
void	ast_jb_get_and_deliver (struct ast_channel c0, struct ast_channel c1)
	Deliver the queued frames that should be delivered now for both channels.
void	ast_jb_get_config (const struct ast_channel chan, struct ast_jb_conf conf)
	Copies a channel's jitterbuffer configuration.
int	ast_jb_get_when_to_wakeup (struct ast_channel c0, struct ast_channel c1, int time_left)
	Calculates the time, left to the closest delivery moment in a bridge.
int	ast_jb_put (struct ast_channel chan, struct ast_frame f)
	Puts a frame into a channel jitterbuffer.
int	ast_jb_read_conf (struct ast_jb_conf conf, const char varname, const char *value)
	Sets jitterbuffer configuration property.

Detailed Description

Common implementation-independent jitterbuffer stuff.

Author:: Slav Klenov <slav@securax.org>

Definition in file abstract_jb.h.

Define Documentation

#define AST_JB_CONF_ENABLE "enable"

Definition at line 68 of file abstract_jb.h.

Referenced by ast_jb_read_conf().

#define AST_JB_CONF_FORCE "force"

Definition at line 69 of file abstract_jb.h.

Referenced by ast_jb_read_conf().

#define AST_JB_CONF_IMPL "impl"

Definition at line 72 of file abstract_jb.h.

Referenced by ast_jb_read_conf().

#define AST_JB_CONF_LOG "log"

Definition at line 73 of file abstract_jb.h.

Referenced by ast_jb_read_conf().

#define AST_JB_CONF_MAX_SIZE "maxsize"

Definition at line 70 of file abstract_jb.h.

Referenced by ast_jb_read_conf().

#define AST_JB_CONF_PREFIX "jb"

Definition at line 67 of file abstract_jb.h.

Referenced by ast_jb_read_conf().

#define AST_JB_CONF_RESYNCH_THRESHOLD "resyncthreshold"

Definition at line 71 of file abstract_jb.h.

Referenced by ast_jb_read_conf().

#define AST_JB_IMPL_NAME_SIZE 12

Definition at line 48 of file abstract_jb.h.

Referenced by create_jb().

Enumeration Type Documentation

anonymous enum

Enumerator:

AST_JB_ENABLED
AST_JB_FORCED
AST_JB_LOG

Definition at line 42 of file abstract_jb.h.

00042      {
00043    AST_JB_ENABLED = (1 << 0),
00044    AST_JB_FORCED =  (1 << 1),
00045    AST_JB_LOG =     (1 << 2)
00046 };

Function Documentation

void ast_jb_configure	(	struct ast_channel *	chan,
		const struct ast_jb_conf *	conf
	)

Configures a jitterbuffer on a channel.

Parameters:

	chan	channel to configure.
	conf	configuration to apply.

Called from a channel driver when a channel is created and its jitterbuffer needs to be configured.

Definition at line 601 of file abstract_jb.c.

References ast_jb::conf, and ast_channel::jb.

Referenced by __oh323_rtp_create(), __oh323_update_info(), alsa_new(), console_new(), dahdi_new(), gtalk_new(), jingle_new(), local_new(), mgcp_new(), misdn_new(), oss_new(), sip_new(), skinny_new(), unistim_new(), and usbradio_new().

00602 {
00603    memcpy(&chan->jb.conf, conf, sizeof(*conf));
00604 }

void ast_jb_destroy ( struct ast_channel * chan )

Destroys jitterbuffer on a channel.

Parameters:

chan

channel.

Called from ast_channel_free() when a channel is destroyed.

Definition at line 526 of file abstract_jb.c.

References ast_clear_flag, ast_frfree, ast_test_flag, ast_verb, ast_jb_impl::destroy, f, ast_jb::impl, ast_channel::jb, JB_CREATED, JB_IMPL_OK, ast_jb::jbobj, ast_jb::logfile, ast_jb_impl::name, and ast_jb_impl::remove.

Referenced by ast_channel_free().

00527 {
00528    struct ast_jb *jb = &chan->jb;
00529    struct ast_jb_impl *jbimpl = jb->impl;
00530    void *jbobj = jb->jbobj;
00531    struct ast_frame *f;
00532 
00533    if (jb->logfile) {
00534       fclose(jb->logfile);
00535       jb->logfile = NULL;
00536    }
00537    
00538    if (ast_test_flag(jb, JB_CREATED)) {
00539       /* Remove and free all frames still queued in jb */
00540       while (jbimpl->remove(jbobj, &f) == JB_IMPL_OK) {
00541          ast_frfree(f);
00542       }
00543       
00544       jbimpl->destroy(jbobj);
00545       jb->jbobj = NULL;
00546       
00547       ast_clear_flag(jb, JB_CREATED);
00548 
00549       ast_verb(3, "%s jitterbuffer destroyed on channel %s\n", jbimpl->name, chan->name);
00550    }
00551 }

int ast_jb_do_usecheck	(	struct ast_channel *	c0,
		struct ast_channel *	c1
	)

Checks the need of a jb use in a generic bridge.

Parameters:

	c0	first bridged channel.
	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 values:

	zero	if there are no jitter buffers in use
	non-zero	if there are

Definition at line 201 of file abstract_jb.c.

References AST_CHAN_TP_CREATESJITTER, AST_CHAN_TP_WANTSJITTER, AST_JB_ENABLED, AST_JB_FORCED, ast_set_flag, ast_test_flag, ast_jb::conf, inuse, ast_channel::jb, jb_choose_impl(), JB_CREATED, JB_TIMEBASE_INITIALIZED, JB_USE, ast_channel_tech::properties, ast_channel::tech, and ast_jb::timebase.

Referenced by ast_generic_bridge().

00203 00204 00205 00206 00207 00208 00209 00210 00211 00212 00213 00214 00215 00216 00217 00218 00219 00220 00221 00222 00223 00224 00225 00226 00227 00228 00229          } 00230 00231       } 00232 00233 00234 00235       } 00236 00237 00238    } 00239 00240 00241 00242 00243 00244 00245 00246 00247 00248          } 00249 00250       } 00251 00252 00253 00254       } 00255 00256 00257    } 00258 00259 00260 }

class="fragment">00202 { struct ast_jb *jb0 = &c0->jb; struct ast_jb *jb1 = &c1->jb; struct ast_jb_conf *conf0 = &jb0->conf; struct ast_jb_conf *conf1 = &jb1->conf; int c0_wants_jitter = c0->tech->properties & AST_CHAN_TP_WANTSJITTER; int c0_creates_jitter = c0->tech->properties & AST_CHAN_TP_CREATESJITTER; int c0_jb_enabled = ast_test_flag(conf0, AST_JB_ENABLED); int c0_force_jb = ast_test_flag(conf0, AST_JB_FORCED); int c0_jb_timebase_initialized = ast_test_flag(jb0, JB_TIMEBASE_INITIALIZED); int c0_jb_created = ast_test_flag(jb0, JB_CREATED); int c1_wants_jitter = c1->tech->properties & AST_CHAN_TP_WANTSJITTER; int c1_creates_jitter = c1->tech->properties & AST_CHAN_TP_CREATESJITTER; int c1_jb_enabled = ast_test_flag(conf1, AST_JB_ENABLED); int c1_force_jb = ast_test_flag(conf1, AST_JB_FORCED); int c1_jb_timebase_initialized = ast_test_flag(jb1, JB_TIMEBASE_INITIALIZED); int c1_jb_created = ast_test_flag(jb1, JB_CREATED); int inuse = 0; /* Determine whether audio going to c0 needs a jitter buffer */ if (((!c0_wants_jitter && c1_creates_jitter) || (c0_force_jb && c1_creates_jitter)) && c0_jb_enabled) { ast_set_flag(jb0, JB_USE); if (!c0_jb_timebase_initialized) { if (c1_jb_timebase_initialized) { memcpy(&jb0->timebase, &jb1->timebase, sizeof(struct timeval)); } else { gettimeofday(&jb0->timebase, NULL); ast_set_flag(jb0, JB_TIMEBASE_INITIALIZED); if (!c0_jb_created) { jb_choose_impl(c0); inuse = 1; /* Determine whether audio going to c1 needs a jitter buffer */ if (((!c1_wants_jitter && c0_creates_jitter) || (c1_force_jb && c0_creates_jitter)) && c1_jb_enabled) { ast_set_flag(jb1, JB_USE); if (!c1_jb_timebase_initialized) { if (c0_jb_timebase_initialized) { memcpy(&jb1->timebase, &jb0->timebase, sizeof(struct timeval)); } else { gettimeofday(&jb1->timebase, NULL); ast_set_flag(jb1, JB_TIMEBASE_INITIALIZED); if (!c1_jb_created) { jb_choose_impl(c1); inuse = 1; return inuse;

void ast_jb_empty_and_reset	(	struct ast_channel *	c0,
		struct ast_channel *	c1
	)

drops all frames from a jitterbuffer and resets it

Parameters:

	c0	one channel of a bridge
	c1	the other channel of the bridge

Definition at line 612 of file abstract_jb.c.

References ast_test_flag, ast_jb_impl::empty_and_reset, ast_jb::impl, ast_channel::jb, JB_CREATED, JB_USE, and ast_jb::jbobj.

Referenced by ast_generic_bridge().

00613 {
00614    struct ast_jb *jb0 = &c0->jb;
00615    struct ast_jb *jb1 = &c1->jb;
00616    int c0_use_jb = ast_test_flag(jb0, JB_USE);
00617    int c0_jb_is_created = ast_test_flag(jb0, JB_CREATED);
00618    int c1_use_jb = ast_test_flag(jb1, JB_USE);
00619    int c1_jb_is_created = ast_test_flag(jb1, JB_CREATED);
00620 
00621    if (c0_use_jb && c0_jb_is_created && jb0->impl->empty_and_reset) {
00622       jb0->impl->empty_and_reset(jb0->jbobj);
00623    }
00624 
00625    if (c1_use_jb && c1_jb_is_created && jb1->impl->empty_and_reset) {
00626       jb1->impl->empty_and_reset(jb1->jbobj);
00627    }
00628 }

void ast_jb_get_and_deliver	(	struct ast_channel *	c0,
		struct ast_channel *	c1
	)

Deliver the queued frames that should be delivered now for both channels.

Parameters:

	c0	first bridged channel.
	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.

Definition at line 367 of file abstract_jb.c.

References ast_test_flag, ast_channel::jb, JB_CREATED, jb_get_and_deliver(), and JB_USE.

Referenced by ast_generic_bridge().

00368 {
00369    struct ast_jb *jb0 = &c0->jb;
00370    struct ast_jb *jb1 = &c1->jb;
00371    int c0_use_jb = ast_test_flag(jb0, JB_USE);
00372    int c0_jb_is_created = ast_test_flag(jb0, JB_CREATED);
00373    int c1_use_jb = ast_test_flag(jb1, JB_USE);
00374    int c1_jb_is_created = ast_test_flag(jb1, JB_CREATED);
00375    
00376    if (c0_use_jb && c0_jb_is_created)
00377       jb_get_and_deliver(c0);
00378    
00379    if (c1_use_jb && c1_jb_is_created)
00380       jb_get_and_deliver(c1);
00381 }

void ast_jb_get_config	(	const struct ast_channel *	chan,
		struct ast_jb_conf *	conf
	)

Copies a channel's jitterbuffer configuration.

Parameters:

	chan	channel.
	conf	destination.

Definition at line 607 of file abstract_jb.c.

References ast_jb::conf, and ast_channel::jb.

00608 {
00609    memcpy(conf, &chan->jb.conf, sizeof(*conf));
00610 }

int ast_jb_get_when_to_wakeup	(	struct ast_channel *	c0,
		struct ast_channel *	c1,
		int	time_left
	)

Calculates the time, left to the closest delivery moment in a bridge.

Parameters:

	c0	first bridged channel.
	c1	second bridged channel.
	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.

Returns:: maximum time to wait.

Definition at line 262 of file abstract_jb.c.

References ast_test_flag, get_now(), ast_channel::jb, JB_CREATED, JB_USE, and ast_jb::next.

Referenced by ast_generic_bridge().

00263 {
00264    struct ast_jb *jb0 = &c0->jb;
00265    struct ast_jb *jb1 = &c1->jb;
00266    int c0_use_jb = ast_test_flag(jb0, JB_USE);
00267    int c0_jb_is_created = ast_test_flag(jb0, JB_CREATED);
00268    int c1_use_jb = ast_test_flag(jb1, JB_USE);
00269    int c1_jb_is_created = ast_test_flag(jb1, JB_CREATED);
00270    int wait, wait0, wait1;
00271    struct timeval tv_now;
00272    
00273    if (time_left == 0) {
00274       /* No time left - the bridge will be retried */
00275       /* TODO: Test disable this */
00276       /*return 0;*/
00277    }
00278    
00279    if (time_left < 0) {
00280       time_left = INT_MAX;
00281    }
00282    
00283    gettimeofday(&tv_now, NULL);
00284    
00285    wait0 = (c0_use_jb && c0_jb_is_created) ? jb0->next - get_now(jb0, &tv_now) : time_left;
00286    wait1 = (c1_use_jb && c1_jb_is_created) ? jb1->next - get_now(jb1, &tv_now) : time_left;
00287    
00288    wait = wait0 < wait1 ? wait0 : wait1;
00289    wait = wait < time_left ? wait : time_left;
00290    
00291    if (wait == INT_MAX) {
00292       wait = -1;
00293    } else if (wait < 1) {
00294       /* don't let wait=0, because this can cause the pbx thread to loop without any sleeping at all */
00295       wait = 1;
00296    }
00297    
00298    return wait;
00299 }

int ast_jb_put	(	struct ast_channel *	chan,
		struct ast_frame *	f
	)

Puts a frame into a channel jitterbuffer.

Parameters:

	chan	channel.
	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 values:

	0	if the frame was queued
	-1	if not

Definition at line 302 of file abstract_jb.c.

References ast_clear_flag, AST_FRAME_DTMF, AST_FRAME_VOICE, ast_frdup(), AST_FRFLAG_HAS_TIMING_INFO, ast_frfree, ast_log(), ast_set_flag, ast_test_flag, create_jb(), ast_jb_impl::force_resync, ast_frame::frametype, get_now(), ast_jb::impl, ast_channel::jb, JB_CREATED, jb_framelog, JB_IMPL_OK, JB_USE, ast_jb::jbobj, ast_frame::len, LOG_ERROR, LOG_WARNING, ast_jb_impl::next, ast_jb::next, ast_jb_impl::put, ast_frame::src, and ast_frame::ts.

Referenced by ast_generic_bridge().

00303 {
00304    struct ast_jb *jb = &chan->jb;
00305    struct ast_jb_impl *jbimpl = jb->impl;
00306    void *jbobj = jb->jbobj;
00307    struct ast_frame *frr;
00308    long now = 0;
00309    
00310    if (!ast_test_flag(jb, JB_USE))
00311       return -1;
00312 
00313    if (f->frametype != AST_FRAME_VOICE) {
00314       if (f->frametype == AST_FRAME_DTMF && ast_test_flag(jb, JB_CREATED)) {
00315          jb_framelog("JB_PUT {now=%ld}: Received DTMF frame. Force resynching jb...\n", now);
00316          jbimpl->force_resync(jbobj);
00317       }
00318       
00319       return -1;
00320    }
00321 
00322    /* We consider an enabled jitterbuffer should receive frames with valid timing info. */
00323    if (!ast_test_flag(f, AST_FRFLAG_HAS_TIMING_INFO) || f->len < 2 || f->ts < 0) {
00324       ast_log(LOG_WARNING, "%s received frame with invalid timing info: "
00325          "has_timing_info=%d, len=%ld, ts=%ld, src=%s\n",
00326          chan->name, ast_test_flag(f, AST_FRFLAG_HAS_TIMING_INFO), f->len, f->ts, f->src);
00327       return -1;
00328    }
00329 
00330    frr = ast_frdup(f);
00331 
00332    if (!frr) {
00333       ast_log(LOG_ERROR, "Failed to isolate frame for the jitterbuffer on channel '%s'\n", chan->name);
00334       return -1;
00335    }
00336 
00337    if (!ast_test_flag(jb, JB_CREATED)) {
00338       if (create_jb(chan, frr)) {
00339          ast_frfree(frr);
00340          /* Disable the jitterbuffer */
00341          ast_clear_flag(jb, JB_USE);
00342          return -1;
00343       }
00344 
00345       ast_set_flag(jb, JB_CREATED);
00346       return 0;
00347    } else {
00348       now = get_now(jb, NULL);
00349       if (jbimpl->put(jbobj, frr, now) != JB_IMPL_OK) {
00350          jb_framelog("JB_PUT {now=%ld}: Dropped frame with ts=%ld and len=%ld\n", now, frr->ts, frr->len);
00351          ast_frfree(frr);
00352          /*return -1;*/
00353          /* TODO: Check this fix - should return 0 here, because the dropped frame shouldn't 
00354             be delivered at all */
00355          return 0;
00356       }
00357 
00358       jb->next = jbimpl->next(jbobj);
00359 
00360       jb_framelog("JB_PUT {now=%ld}: Queued frame with ts=%ld and len=%ld\n", now, frr->ts, frr->len);
00361 
00362       return 0;
00363    }
00364 }

int ast_jb_read_conf	(	struct ast_jb_conf *	conf,
		const char *	varname,
		const char *	value
	)

Sets jitterbuffer configuration property.

Parameters:

	conf	configuration to store the property in.
	varname	property name.
	value	property value.

Called from a channel driver to build a jitterbuffer configuration typically when reading a configuration file. It is not necessary 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.

Returns:: zero if the property was set to the configuration, -1 if not.

Definition at line 567 of file abstract_jb.c.

References AST_JB_CONF_ENABLE, AST_JB_CONF_FORCE, AST_JB_CONF_IMPL, AST_JB_CONF_LOG, AST_JB_CONF_MAX_SIZE, AST_JB_CONF_PREFIX, AST_JB_CONF_RESYNCH_THRESHOLD, AST_JB_ENABLED, AST_JB_FORCED, AST_JB_LOG, ast_set2_flag, ast_strlen_zero(), ast_true(), ast_jb_conf::impl, ast_jb_conf::max_size, name, and ast_jb_conf::resync_threshold.

Referenced by _build_general_config(), gtalk_load_config(), jingle_load_config(), load_module(), process_dahdi(), reload_config(), store_config(), and store_config_core().

00568 {
00569    int prefixlen = sizeof(AST_JB_CONF_PREFIX) - 1;
00570    const char *name;
00571    int tmp;
00572    
00573    if (strncasecmp(AST_JB_CONF_PREFIX, varname, prefixlen))
00574       return -1;
00575    
00576    name = varname + prefixlen;
00577    
00578    if (!strcasecmp(name, AST_JB_CONF_ENABLE)) {
00579       ast_set2_flag(conf, ast_true(value), AST_JB_ENABLED);
00580    } else if (!strcasecmp(name, AST_JB_CONF_FORCE)) {
00581       ast_set2_flag(conf, ast_true(value), AST_JB_FORCED);
00582    } else if (!strcasecmp(name, AST_JB_CONF_MAX_SIZE)) {
00583       if ((tmp = atoi(value)) > 0)
00584          conf->max_size = tmp;
00585    } else if (!strcasecmp(name, AST_JB_CONF_RESYNCH_THRESHOLD)) {
00586       if ((tmp = atoi(value)) > 0)
00587          conf->resync_threshold = tmp;
00588    } else if (!strcasecmp(name, AST_JB_CONF_IMPL)) {
00589       if (!ast_strlen_zero(value))
00590          snprintf(conf->impl, sizeof(conf->impl), "%s", value);
00591    } else if (!strcasecmp(name, AST_JB_CONF_LOG)) {
00592       ast_set2_flag(conf, ast_true(value), AST_JB_LOG);
00593    } else {
00594       return -1;
00595    }
00596    
00597    return 0;
00598 }

Asterisk developer's documentation

abstract_jb.h File Reference

Data Structures

Defines

Enumerations

Functions

Detailed Description

Define Documentation

Enumeration Type Documentation

Function Documentation