Mon Aug 31 12:30:13 2015

Asterisk developer's documentation


abstract_jb.h File Reference

Common implementation-independent jitterbuffer stuff. More...

#include <sys/time.h>
#include "asterisk/frame_defs.h"

Go to the source code of 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_CONF_TARGET_EXTRA   "targetextra"
#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 72 of file abstract_jb.h.

Referenced by ast_jb_read_conf().

#define AST_JB_CONF_FORCE   "force"

Definition at line 73 of file abstract_jb.h.

Referenced by ast_jb_read_conf().

#define AST_JB_CONF_IMPL   "impl"

Definition at line 77 of file abstract_jb.h.

Referenced by ast_jb_read_conf().

#define AST_JB_CONF_LOG   "log"

Definition at line 78 of file abstract_jb.h.

Referenced by ast_jb_read_conf().

#define AST_JB_CONF_MAX_SIZE   "maxsize"

Definition at line 74 of file abstract_jb.h.

Referenced by ast_jb_read_conf().

#define AST_JB_CONF_PREFIX   "jb"

Definition at line 71 of file abstract_jb.h.

Referenced by ast_jb_read_conf().

#define AST_JB_CONF_RESYNCH_THRESHOLD   "resyncthreshold"

Definition at line 75 of file abstract_jb.h.

Referenced by ast_jb_read_conf().

#define AST_JB_CONF_TARGET_EXTRA   "targetextra"

Definition at line 76 of file abstract_jb.h.

Referenced by ast_jb_read_conf().

#define AST_JB_IMPL_NAME_SIZE   12

Definition at line 50 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 44 of file abstract_jb.h.

00044      {
00045    AST_JB_ENABLED = (1 << 0),
00046    AST_JB_FORCED =  (1 << 1),
00047    AST_JB_LOG =     (1 << 2)
00048 };


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 616 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(), and unistim_new().

00617 {
00618    memcpy(&chan->jb.conf, conf, sizeof(*conf));
00619 }

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 536 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_destructor().

00537 {
00538    struct ast_jb *jb = &chan->jb;
00539    const struct ast_jb_impl *jbimpl = jb->impl;
00540    void *jbobj = jb->jbobj;
00541    struct ast_frame *f;
00542 
00543    if (jb->logfile) {
00544       fclose(jb->logfile);
00545       jb->logfile = NULL;
00546    }
00547 
00548    if (ast_test_flag(jb, JB_CREATED)) {
00549       /* Remove and free all frames still queued in jb */
00550       while (jbimpl->remove(jbobj, &f) == JB_IMPL_OK) {
00551          ast_frfree(f);
00552       }
00553 
00554       jbimpl->destroy(jbobj);
00555       jb->jbobj = NULL;
00556 
00557       ast_clear_flag(jb, JB_CREATED);
00558 
00559       ast_verb(3, "%s jitterbuffer destroyed on channel %s\n", jbimpl->name, chan->name);
00560    }
00561 }

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 205 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, 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().

00206 {
00207    struct ast_jb *jb0 = &c0->jb;
00208    struct ast_jb *jb1 = &c1->jb;
00209    struct ast_jb_conf *conf0 = &jb0->conf;
00210    struct ast_jb_conf *conf1 = &jb1->conf;
00211    int c0_wants_jitter = c0->tech->properties & AST_CHAN_TP_WANTSJITTER;
00212    int c0_creates_jitter = c0->tech->properties & AST_CHAN_TP_CREATESJITTER;
00213    int c0_jb_enabled = ast_test_flag(conf0, AST_JB_ENABLED);
00214    int c0_force_jb = ast_test_flag(conf0, AST_JB_FORCED);
00215    int c0_jb_timebase_initialized = ast_test_flag(jb0, JB_TIMEBASE_INITIALIZED);
00216    int c0_jb_created = ast_test_flag(jb0, JB_CREATED);
00217    int c1_wants_jitter = c1->tech->properties & AST_CHAN_TP_WANTSJITTER;
00218    int c1_creates_jitter = c1->tech->properties & AST_CHAN_TP_CREATESJITTER;
00219    int c1_jb_enabled = ast_test_flag(conf1, AST_JB_ENABLED);
00220    int c1_force_jb = ast_test_flag(conf1, AST_JB_FORCED);
00221    int c1_jb_timebase_initialized = ast_test_flag(jb1, JB_TIMEBASE_INITIALIZED);
00222    int c1_jb_created = ast_test_flag(jb1, JB_CREATED);
00223    int inuse = 0;
00224 
00225    /* Determine whether audio going to c0 needs a jitter buffer */
00226    if (((!c0_wants_jitter && c1_creates_jitter) || (c0_force_jb && c1_creates_jitter)) && c0_jb_enabled) {
00227       ast_set_flag(jb0, JB_USE);
00228       if (!c0_jb_timebase_initialized) {
00229          if (c1_jb_timebase_initialized) {
00230             memcpy(&jb0->timebase, &jb1->timebase, sizeof(struct timeval));
00231          } else {
00232             gettimeofday(&jb0->timebase, NULL);
00233          }
00234          ast_set_flag(jb0, JB_TIMEBASE_INITIALIZED);
00235       }
00236 
00237       if (!c0_jb_created) {
00238          jb_choose_impl(c0);
00239       }
00240 
00241       inuse = 1;
00242    }
00243 
00244    /* Determine whether audio going to c1 needs a jitter buffer */
00245    if (((!c1_wants_jitter && c0_creates_jitter) || (c1_force_jb && c0_creates_jitter)) && c1_jb_enabled) {
00246       ast_set_flag(jb1, JB_USE);
00247       if (!c1_jb_timebase_initialized) {
00248          if (c0_jb_timebase_initialized) {
00249             memcpy(&jb1->timebase, &jb0->timebase, sizeof(struct timeval));
00250          } else {
00251             gettimeofday(&jb1->timebase, NULL);
00252          }
00253          ast_set_flag(jb1, JB_TIMEBASE_INITIALIZED);
00254       }
00255 
00256       if (!c1_jb_created) {
00257          jb_choose_impl(c1);
00258       }
00259 
00260       inuse = 1;
00261    }
00262 
00263    return inuse;
00264 }

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 627 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().

00628 {
00629    struct ast_jb *jb0 = &c0->jb;
00630    struct ast_jb *jb1 = &c1->jb;
00631    int c0_use_jb = ast_test_flag(jb0, JB_USE);
00632    int c0_jb_is_created = ast_test_flag(jb0, JB_CREATED);
00633    int c1_use_jb = ast_test_flag(jb1, JB_USE);
00634    int c1_jb_is_created = ast_test_flag(jb1, JB_CREATED);
00635 
00636    if (c0_use_jb && c0_jb_is_created && jb0->impl->empty_and_reset) {
00637       jb0->impl->empty_and_reset(jb0->jbobj);
00638    }
00639 
00640    if (c1_use_jb && c1_jb_is_created && jb1->impl->empty_and_reset) {
00641       jb1->impl->empty_and_reset(jb1->jbobj);
00642    }
00643 }

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 371 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().

00372 {
00373    struct ast_jb *jb0 = &c0->jb;
00374    struct ast_jb *jb1 = &c1->jb;
00375    int c0_use_jb = ast_test_flag(jb0, JB_USE);
00376    int c0_jb_is_created = ast_test_flag(jb0, JB_CREATED);
00377    int c1_use_jb = ast_test_flag(jb1, JB_USE);
00378    int c1_jb_is_created = ast_test_flag(jb1, JB_CREATED);
00379 
00380    if (c0_use_jb && c0_jb_is_created)
00381       jb_get_and_deliver(c0);
00382 
00383    if (c1_use_jb && c1_jb_is_created)
00384       jb_get_and_deliver(c1);
00385 }

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 622 of file abstract_jb.c.

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

00623 {
00624    memcpy(conf, &chan->jb.conf, sizeof(*conf));
00625 }

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 266 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().

00267 {
00268    struct ast_jb *jb0 = &c0->jb;
00269    struct ast_jb *jb1 = &c1->jb;
00270    int c0_use_jb = ast_test_flag(jb0, JB_USE);
00271    int c0_jb_is_created = ast_test_flag(jb0, JB_CREATED);
00272    int c1_use_jb = ast_test_flag(jb1, JB_USE);
00273    int c1_jb_is_created = ast_test_flag(jb1, JB_CREATED);
00274    int wait, wait0, wait1;
00275    struct timeval tv_now;
00276 
00277    if (time_left == 0) {
00278       /* No time left - the bridge will be retried */
00279       /* TODO: Test disable this */
00280       /*return 0;*/
00281    }
00282 
00283    if (time_left < 0) {
00284       time_left = INT_MAX;
00285    }
00286 
00287    gettimeofday(&tv_now, NULL);
00288 
00289    wait0 = (c0_use_jb && c0_jb_is_created) ? jb0->next - get_now(jb0, &tv_now) : time_left;
00290    wait1 = (c1_use_jb && c1_jb_is_created) ? jb1->next - get_now(jb1, &tv_now) : time_left;
00291 
00292    wait = wait0 < wait1 ? wait0 : wait1;
00293    wait = wait < time_left ? wait : time_left;
00294 
00295    if (wait == INT_MAX) {
00296       wait = -1;
00297    } else if (wait < 1) {
00298       /* don't let wait=0, because this can cause the pbx thread to loop without any sleeping at all */
00299       wait = 1;
00300    }
00301 
00302    return wait;
00303 }

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 306 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().

00307 {
00308    struct ast_jb *jb = &chan->jb;
00309    const struct ast_jb_impl *jbimpl = jb->impl;
00310    void *jbobj = jb->jbobj;
00311    struct ast_frame *frr;
00312    long now = 0;
00313 
00314    if (!ast_test_flag(jb, JB_USE))
00315       return -1;
00316 
00317    if (f->frametype != AST_FRAME_VOICE) {
00318       if (f->frametype == AST_FRAME_DTMF && ast_test_flag(jb, JB_CREATED)) {
00319          jb_framelog("JB_PUT {now=%ld}: Received DTMF frame. Force resynching jb...\n", now);
00320          jbimpl->force_resync(jbobj);
00321       }
00322 
00323       return -1;
00324    }
00325 
00326    /* We consider an enabled jitterbuffer should receive frames with valid timing info. */
00327    if (!ast_test_flag(f, AST_FRFLAG_HAS_TIMING_INFO) || f->len < 2 || f->ts < 0) {
00328       ast_log(LOG_WARNING, "%s received frame with invalid timing info: "
00329          "has_timing_info=%u, len=%ld, ts=%ld, src=%s\n",
00330          chan->name, ast_test_flag(f, AST_FRFLAG_HAS_TIMING_INFO), f->len, f->ts, f->src);
00331       return -1;
00332    }
00333 
00334    frr = ast_frdup(f);
00335 
00336    if (!frr) {
00337       ast_log(LOG_ERROR, "Failed to isolate frame for the jitterbuffer on channel '%s'\n", chan->name);
00338       return -1;
00339    }
00340 
00341    if (!ast_test_flag(jb, JB_CREATED)) {
00342       if (create_jb(chan, frr)) {
00343          ast_frfree(frr);
00344          /* Disable the jitterbuffer */
00345          ast_clear_flag(jb, JB_USE);
00346          return -1;
00347       }
00348 
00349       ast_set_flag(jb, JB_CREATED);
00350       return 0;
00351    } else {
00352       now = get_now(jb, NULL);
00353       if (jbimpl->put(jbobj, frr, now) != JB_IMPL_OK) {
00354          jb_framelog("JB_PUT {now=%ld}: Dropped frame with ts=%ld and len=%ld\n", now, frr->ts, frr->len);
00355          ast_frfree(frr);
00356          /*return -1;*/
00357          /* TODO: Check this fix - should return 0 here, because the dropped frame shouldn't
00358             be delivered at all */
00359          return 0;
00360       }
00361 
00362       jb->next = jbimpl->next(jbobj);
00363 
00364       jb_framelog("JB_PUT {now=%ld}: Queued frame with ts=%ld and len=%ld\n", now, frr->ts, frr->len);
00365 
00366       return 0;
00367    }
00368 }

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 577 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_CONF_TARGET_EXTRA, 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, ast_jb_conf::resync_threshold, and ast_jb_conf::target_extra.

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

00578 {
00579    int prefixlen = sizeof(AST_JB_CONF_PREFIX) - 1;
00580    const char *name;
00581    int tmp;
00582 
00583    if (strncasecmp(AST_JB_CONF_PREFIX, varname, prefixlen)) {
00584       return -1;
00585    }
00586 
00587    name = varname + prefixlen;
00588 
00589    if (!strcasecmp(name, AST_JB_CONF_ENABLE)) {
00590       ast_set2_flag(conf, ast_true(value), AST_JB_ENABLED);
00591    } else if (!strcasecmp(name, AST_JB_CONF_FORCE)) {
00592       ast_set2_flag(conf, ast_true(value), AST_JB_FORCED);
00593    } else if (!strcasecmp(name, AST_JB_CONF_MAX_SIZE)) {
00594       if ((tmp = atoi(value)) > 0)
00595          conf->max_size = tmp;
00596    } else if (!strcasecmp(name, AST_JB_CONF_RESYNCH_THRESHOLD)) {
00597       if ((tmp = atoi(value)) > 0)
00598          conf->resync_threshold = tmp;
00599    } else if (!strcasecmp(name, AST_JB_CONF_IMPL)) {
00600       if (!ast_strlen_zero(value))
00601          snprintf(conf->impl, sizeof(conf->impl), "%s", value);
00602    } else if (!strcasecmp(name, AST_JB_CONF_TARGET_EXTRA)) {
00603       if (sscanf(value, "%30d", &tmp) == 1) {
00604          conf->target_extra = tmp;
00605       }
00606    } else if (!strcasecmp(name, AST_JB_CONF_LOG)) {
00607       ast_set2_flag(conf, ast_true(value), AST_JB_LOG);
00608    } else {
00609       return -1;
00610    }
00611 
00612    return 0;
00613 }


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