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Asterisk developer's documentation


abstract_jb.c

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00001 /*
00002  * abstract_jb: common implementation-independent jitterbuffer stuff
00003  *
00004  * Copyright (C) 2005, Attractel OOD
00005  *
00006  * Contributors:
00007  * Slav Klenov <slav@securax.org>
00008  *
00009  * See http://www.asterisk.org for more information about
00010  * the Asterisk project. Please do not directly contact
00011  * any of the maintainers of this project for assistance;
00012  * the project provides a web site, mailing lists and IRC
00013  * channels for your use.
00014  *
00015  * This program is free software, distributed under the terms of
00016  * the GNU General Public License Version 2. See the LICENSE file
00017  * at the top of the source tree.
00018  *
00019  * A license has been granted to Digium (via disclaimer) for the use of
00020  * this code.
00021  */
00022 
00023 /*! \file
00024  *
00025  * \brief Common implementation-independent jitterbuffer stuff.
00026  *
00027  * \author Slav Klenov <slav@securax.org>
00028  *
00029  *
00030  */
00031 
00032 #include "asterisk.h"
00033 
00034 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 297311 $")
00035 
00036 #include "asterisk/frame.h"
00037 #include "asterisk/channel.h"
00038 #include "asterisk/term.h"
00039 #include "asterisk/utils.h"
00040 
00041 #include "asterisk/abstract_jb.h"
00042 #include "fixedjitterbuf.h"
00043 #include "jitterbuf.h"
00044 
00045 /*! Internal jb flags */
00046 enum {
00047    JB_USE =                  (1 << 0),
00048    JB_TIMEBASE_INITIALIZED = (1 << 1),
00049    JB_CREATED =              (1 << 2)
00050 };
00051 
00052 /* Hooks for the abstract jb implementation */
00053 
00054 /*! \brief Create */
00055 typedef void * (*jb_create_impl)(struct ast_jb_conf *general_config, long resynch_threshold);
00056 /*! \brief Destroy */
00057 typedef void (*jb_destroy_impl)(void *jb);
00058 /*! \brief Put first frame */
00059 typedef int (*jb_put_first_impl)(void *jb, struct ast_frame *fin, long now);
00060 /*! \brief Put frame */
00061 typedef int (*jb_put_impl)(void *jb, struct ast_frame *fin, long now);
00062 /*! \brief Get frame for now */
00063 typedef int (*jb_get_impl)(void *jb, struct ast_frame **fout, long now, long interpl);
00064 /*! \brief Get next */
00065 typedef long (*jb_next_impl)(void *jb);
00066 /*! \brief Remove first frame */
00067 typedef int (*jb_remove_impl)(void *jb, struct ast_frame **fout);
00068 /*! \brief Force resynch */
00069 typedef void (*jb_force_resynch_impl)(void *jb);
00070 /*! \brief Empty and reset jb */
00071 typedef void (*jb_empty_and_reset_impl)(void *jb);
00072 
00073 /*!
00074  * \brief Jitterbuffer implementation private struct.
00075  */
00076 struct ast_jb_impl
00077 {
00078    char name[AST_JB_IMPL_NAME_SIZE];
00079    jb_create_impl create;
00080    jb_destroy_impl destroy;
00081    jb_put_first_impl put_first;
00082    jb_put_impl put;
00083    jb_get_impl get;
00084    jb_next_impl next;
00085    jb_remove_impl remove;
00086    jb_force_resynch_impl force_resync;
00087    jb_empty_and_reset_impl empty_and_reset;
00088 };
00089 
00090 /* Implementation functions */
00091 /* fixed */
00092 static void *jb_create_fixed(struct ast_jb_conf *general_config, long resynch_threshold);
00093 static void jb_destroy_fixed(void *jb);
00094 static int jb_put_first_fixed(void *jb, struct ast_frame *fin, long now);
00095 static int jb_put_fixed(void *jb, struct ast_frame *fin, long now);
00096 static int jb_get_fixed(void *jb, struct ast_frame **fout, long now, long interpl);
00097 static long jb_next_fixed(void *jb);
00098 static int jb_remove_fixed(void *jb, struct ast_frame **fout);
00099 static void jb_force_resynch_fixed(void *jb);
00100 static void jb_empty_and_reset_fixed(void *jb);
00101 /* adaptive */
00102 static void * jb_create_adaptive(struct ast_jb_conf *general_config, long resynch_threshold);
00103 static void jb_destroy_adaptive(void *jb);
00104 static int jb_put_first_adaptive(void *jb, struct ast_frame *fin, long now);
00105 static int jb_put_adaptive(void *jb, struct ast_frame *fin, long now);
00106 static int jb_get_adaptive(void *jb, struct ast_frame **fout, long now, long interpl);
00107 static long jb_next_adaptive(void *jb);
00108 static int jb_remove_adaptive(void *jb, struct ast_frame **fout);
00109 static void jb_force_resynch_adaptive(void *jb);
00110 static void jb_empty_and_reset_adaptive(void *jb);
00111 
00112 /* Available jb implementations */
00113 static struct ast_jb_impl avail_impl[] =
00114 {
00115    {
00116       .name = "fixed",
00117       .create = jb_create_fixed,
00118       .destroy = jb_destroy_fixed,
00119       .put_first = jb_put_first_fixed,
00120       .put = jb_put_fixed,
00121       .get = jb_get_fixed,
00122       .next = jb_next_fixed,
00123       .remove = jb_remove_fixed,
00124       .force_resync = jb_force_resynch_fixed,
00125       .empty_and_reset = jb_empty_and_reset_fixed,
00126    },
00127    {
00128       .name = "adaptive",
00129       .create = jb_create_adaptive,
00130       .destroy = jb_destroy_adaptive,
00131       .put_first = jb_put_first_adaptive,
00132       .put = jb_put_adaptive,
00133       .get = jb_get_adaptive,
00134       .next = jb_next_adaptive,
00135       .remove = jb_remove_adaptive,
00136       .force_resync = jb_force_resynch_adaptive,
00137       .empty_and_reset = jb_empty_and_reset_adaptive,
00138    }
00139 };
00140 
00141 static int default_impl = 0;
00142 
00143 
00144 /*! Abstract return codes */
00145 enum {
00146    JB_IMPL_OK,
00147    JB_IMPL_DROP,
00148    JB_IMPL_INTERP,
00149    JB_IMPL_NOFRAME
00150 };
00151 
00152 /* Translations between impl and abstract return codes */
00153 static int fixed_to_abstract_code[] =
00154    {JB_IMPL_OK, JB_IMPL_DROP, JB_IMPL_INTERP, JB_IMPL_NOFRAME};
00155 static int adaptive_to_abstract_code[] =
00156    {JB_IMPL_OK, JB_IMPL_NOFRAME, JB_IMPL_NOFRAME, JB_IMPL_INTERP, JB_IMPL_DROP, JB_IMPL_OK};
00157 
00158 /* JB_GET actions (used only for the frames log) */
00159 static char *jb_get_actions[] = {"Delivered", "Dropped", "Interpolated", "No"};
00160 
00161 /*! \brief Macros for the frame log files */
00162 #define jb_framelog(...) do { \
00163    if (jb->logfile) { \
00164       fprintf(jb->logfile, __VA_ARGS__); \
00165       fflush(jb->logfile); \
00166    } \
00167 } while (0)
00168 
00169 
00170 /* Internal utility functions */
00171 static void jb_choose_impl(struct ast_channel *chan);
00172 static void jb_get_and_deliver(struct ast_channel *chan);
00173 static int create_jb(struct ast_channel *chan, struct ast_frame *first_frame);
00174 static long get_now(struct ast_jb *jb, struct timeval *tv);
00175 
00176 
00177 /* Interface ast jb functions impl */
00178 
00179 
00180 static void jb_choose_impl(struct ast_channel *chan)
00181 {
00182    struct ast_jb *jb = &chan->jb;
00183    struct ast_jb_conf *jbconf = &jb->conf;
00184    struct ast_jb_impl *test_impl;
00185    int i, avail_impl_count = ARRAY_LEN(avail_impl);
00186 
00187    jb->impl = &avail_impl[default_impl];
00188 
00189    if (ast_strlen_zero(jbconf->impl)) {
00190       return;
00191    }
00192 
00193    for (i = 0; i < avail_impl_count; i++) {
00194       test_impl = &avail_impl[i];
00195       if (!strcasecmp(jbconf->impl, test_impl->name)) {
00196          jb->impl = test_impl;
00197          return;
00198       }
00199    }
00200 }
00201 
00202 int ast_jb_do_usecheck(struct ast_channel *c0, struct ast_channel *c1)
00203 {
00204    struct ast_jb *jb0 = &c0->jb;
00205    struct ast_jb *jb1 = &c1->jb;
00206    struct ast_jb_conf *conf0 = &jb0->conf;
00207    struct ast_jb_conf *conf1 = &jb1->conf;
00208    int c0_wants_jitter = c0->tech->properties & AST_CHAN_TP_WANTSJITTER;
00209    int c0_creates_jitter = c0->tech->properties & AST_CHAN_TP_CREATESJITTER;
00210    int c0_jb_enabled = ast_test_flag(conf0, AST_JB_ENABLED);
00211    int c0_force_jb = ast_test_flag(conf0, AST_JB_FORCED);
00212    int c0_jb_timebase_initialized = ast_test_flag(jb0, JB_TIMEBASE_INITIALIZED);
00213    int c0_jb_created = ast_test_flag(jb0, JB_CREATED);
00214    int c1_wants_jitter = c1->tech->properties & AST_CHAN_TP_WANTSJITTER;
00215    int c1_creates_jitter = c1->tech->properties & AST_CHAN_TP_CREATESJITTER;
00216    int c1_jb_enabled = ast_test_flag(conf1, AST_JB_ENABLED);
00217    int c1_force_jb = ast_test_flag(conf1, AST_JB_FORCED);
00218    int c1_jb_timebase_initialized = ast_test_flag(jb1, JB_TIMEBASE_INITIALIZED);
00219    int c1_jb_created = ast_test_flag(jb1, JB_CREATED);
00220    int inuse = 0;
00221 
00222    /* Determine whether audio going to c0 needs a jitter buffer */
00223    if (((!c0_wants_jitter && c1_creates_jitter) || (c0_force_jb && c1_creates_jitter)) && c0_jb_enabled) {
00224       ast_set_flag(jb0, JB_USE);
00225       if (!c0_jb_timebase_initialized) {
00226          if (c1_jb_timebase_initialized) {
00227             memcpy(&jb0->timebase, &jb1->timebase, sizeof(struct timeval));
00228          } else {
00229             gettimeofday(&jb0->timebase, NULL);
00230          }
00231          ast_set_flag(jb0, JB_TIMEBASE_INITIALIZED);
00232       }
00233 
00234       if (!c0_jb_created) {
00235          jb_choose_impl(c0);
00236       }
00237 
00238       inuse = 1;
00239    }
00240 
00241    /* Determine whether audio going to c1 needs a jitter buffer */
00242    if (((!c1_wants_jitter && c0_creates_jitter) || (c1_force_jb && c0_creates_jitter)) && c1_jb_enabled) {
00243       ast_set_flag(jb1, JB_USE);
00244       if (!c1_jb_timebase_initialized) {
00245          if (c0_jb_timebase_initialized) {
00246             memcpy(&jb1->timebase, &jb0->timebase, sizeof(struct timeval));
00247          } else {
00248             gettimeofday(&jb1->timebase, NULL);
00249          }
00250          ast_set_flag(jb1, JB_TIMEBASE_INITIALIZED);
00251       }
00252 
00253       if (!c1_jb_created) {
00254          jb_choose_impl(c1);
00255       }
00256 
00257       inuse = 1;
00258    }
00259 
00260    return inuse;
00261 }
00262 
00263 int ast_jb_get_when_to_wakeup(struct ast_channel *c0, struct ast_channel *c1, int time_left)
00264 {
00265    struct ast_jb *jb0 = &c0->jb;
00266    struct ast_jb *jb1 = &c1->jb;
00267    int c0_use_jb = ast_test_flag(jb0, JB_USE);
00268    int c0_jb_is_created = ast_test_flag(jb0, JB_CREATED);
00269    int c1_use_jb = ast_test_flag(jb1, JB_USE);
00270    int c1_jb_is_created = ast_test_flag(jb1, JB_CREATED);
00271    int wait, wait0, wait1;
00272    struct timeval tv_now;
00273 
00274    if (time_left == 0) {
00275       /* No time left - the bridge will be retried */
00276       /* TODO: Test disable this */
00277       /*return 0;*/
00278    }
00279 
00280    if (time_left < 0) {
00281       time_left = INT_MAX;
00282    }
00283 
00284    gettimeofday(&tv_now, NULL);
00285 
00286    wait0 = (c0_use_jb && c0_jb_is_created) ? jb0->next - get_now(jb0, &tv_now) : time_left;
00287    wait1 = (c1_use_jb && c1_jb_is_created) ? jb1->next - get_now(jb1, &tv_now) : time_left;
00288 
00289    wait = wait0 < wait1 ? wait0 : wait1;
00290    wait = wait < time_left ? wait : time_left;
00291 
00292    if (wait == INT_MAX) {
00293       wait = -1;
00294    } else if (wait < 1) {
00295       /* don't let wait=0, because this can cause the pbx thread to loop without any sleeping at all */
00296       wait = 1;
00297    }
00298 
00299    return wait;
00300 }
00301 
00302 
00303 int ast_jb_put(struct ast_channel *chan, struct ast_frame *f)
00304 {
00305    struct ast_jb *jb = &chan->jb;
00306    struct ast_jb_impl *jbimpl = jb->impl;
00307    void *jbobj = jb->jbobj;
00308    struct ast_frame *frr;
00309    long now = 0;
00310 
00311    if (!ast_test_flag(jb, JB_USE))
00312       return -1;
00313 
00314    if (f->frametype != AST_FRAME_VOICE) {
00315       if (f->frametype == AST_FRAME_DTMF && ast_test_flag(jb, JB_CREATED)) {
00316          jb_framelog("JB_PUT {now=%ld}: Received DTMF frame. Force resynching jb...\n", now);
00317          jbimpl->force_resync(jbobj);
00318       }
00319 
00320       return -1;
00321    }
00322 
00323    /* We consider an enabled jitterbuffer should receive frames with valid timing info. */
00324    if (!ast_test_flag(f, AST_FRFLAG_HAS_TIMING_INFO) || f->len < 2 || f->ts < 0) {
00325       ast_log(LOG_WARNING, "%s received frame with invalid timing info: "
00326          "has_timing_info=%d, len=%ld, ts=%ld, src=%s\n",
00327          chan->name, ast_test_flag(f, AST_FRFLAG_HAS_TIMING_INFO), f->len, f->ts, f->src);
00328       return -1;
00329    }
00330 
00331    frr = ast_frdup(f);
00332 
00333    if (!frr) {
00334       ast_log(LOG_ERROR, "Failed to isolate frame for the jitterbuffer on channel '%s'\n", chan->name);
00335       return -1;
00336    }
00337 
00338    if (!ast_test_flag(jb, JB_CREATED)) {
00339       if (create_jb(chan, frr)) {
00340          ast_frfree(frr);
00341          /* Disable the jitterbuffer */
00342          ast_clear_flag(jb, JB_USE);
00343          return -1;
00344       }
00345 
00346       ast_set_flag(jb, JB_CREATED);
00347       return 0;
00348    } else {
00349       now = get_now(jb, NULL);
00350       if (jbimpl->put(jbobj, frr, now) != JB_IMPL_OK) {
00351          jb_framelog("JB_PUT {now=%ld}: Dropped frame with ts=%ld and len=%ld\n", now, frr->ts, frr->len);
00352          ast_frfree(frr);
00353          /*return -1;*/
00354          /* TODO: Check this fix - should return 0 here, because the dropped frame shouldn't
00355             be delivered at all */
00356          return 0;
00357       }
00358 
00359       jb->next = jbimpl->next(jbobj);
00360 
00361       jb_framelog("JB_PUT {now=%ld}: Queued frame with ts=%ld and len=%ld\n", now, frr->ts, frr->len);
00362 
00363       return 0;
00364    }
00365 }
00366 
00367 
00368 void ast_jb_get_and_deliver(struct ast_channel *c0, struct ast_channel *c1)
00369 {
00370    struct ast_jb *jb0 = &c0->jb;
00371    struct ast_jb *jb1 = &c1->jb;
00372    int c0_use_jb = ast_test_flag(jb0, JB_USE);
00373    int c0_jb_is_created = ast_test_flag(jb0, JB_CREATED);
00374    int c1_use_jb = ast_test_flag(jb1, JB_USE);
00375    int c1_jb_is_created = ast_test_flag(jb1, JB_CREATED);
00376 
00377    if (c0_use_jb && c0_jb_is_created)
00378       jb_get_and_deliver(c0);
00379 
00380    if (c1_use_jb && c1_jb_is_created)
00381       jb_get_and_deliver(c1);
00382 }
00383 
00384 
00385 static void jb_get_and_deliver(struct ast_channel *chan)
00386 {
00387    struct ast_jb *jb = &chan->jb;
00388    struct ast_jb_impl *jbimpl = jb->impl;
00389    void *jbobj = jb->jbobj;
00390    struct ast_frame *f, finterp = { .frametype = AST_FRAME_VOICE, };
00391    long now;
00392    int interpolation_len, res;
00393 
00394    now = get_now(jb, NULL);
00395    jb->next = jbimpl->next(jbobj);
00396    if (now < jb->next) {
00397       jb_framelog("\tJB_GET {now=%ld}: now < next=%ld\n", now, jb->next);
00398       return;
00399    }
00400 
00401    while (now >= jb->next) {
00402       interpolation_len = ast_codec_interp_len(jb->last_format);
00403 
00404       res = jbimpl->get(jbobj, &f, now, interpolation_len);
00405 
00406       switch (res) {
00407       case JB_IMPL_OK:
00408          /* deliver the frame */
00409          ast_write(chan, f);
00410       case JB_IMPL_DROP:
00411          jb_framelog("\tJB_GET {now=%ld}: %s frame with ts=%ld and len=%ld\n",
00412             now, jb_get_actions[res], f->ts, f->len);
00413          jb->last_format = f->subclass;
00414          ast_frfree(f);
00415          break;
00416       case JB_IMPL_INTERP:
00417          /* interpolate a frame */
00418          f = &finterp;
00419          f->subclass = jb->last_format;
00420          f->samples  = interpolation_len * 8;
00421          f->src  = "JB interpolation";
00422          f->delivery = ast_tvadd(jb->timebase, ast_samp2tv(jb->next, 1000));
00423          f->offset = AST_FRIENDLY_OFFSET;
00424          /* deliver the interpolated frame */
00425          ast_write(chan, f);
00426          jb_framelog("\tJB_GET {now=%ld}: Interpolated frame with len=%d\n", now, interpolation_len);
00427          break;
00428       case JB_IMPL_NOFRAME:
00429          ast_log(LOG_WARNING,
00430             "JB_IMPL_NOFRAME is returned from the %s jb when now=%ld >= next=%ld, jbnext=%ld!\n",
00431             jbimpl->name, now, jb->next, jbimpl->next(jbobj));
00432          jb_framelog("\tJB_GET {now=%ld}: No frame for now!?\n", now);
00433          return;
00434       default:
00435          ast_log(LOG_ERROR, "This should never happen!\n");
00436          ast_assert("JB type unknown" == NULL);
00437          break;
00438       }
00439 
00440       jb->next = jbimpl->next(jbobj);
00441    }
00442 }
00443 
00444 
00445 static int create_jb(struct ast_channel *chan, struct ast_frame *frr)
00446 {
00447    struct ast_jb *jb = &chan->jb;
00448    struct ast_jb_conf *jbconf = &jb->conf;
00449    struct ast_jb_impl *jbimpl = jb->impl;
00450    void *jbobj;
00451    struct ast_channel *bridged;
00452    long now;
00453    char logfile_pathname[20 + AST_JB_IMPL_NAME_SIZE + 2*AST_CHANNEL_NAME + 1];
00454    char name1[AST_CHANNEL_NAME], name2[AST_CHANNEL_NAME], *tmp;
00455    int res;
00456 
00457    jbobj = jb->jbobj = jbimpl->create(jbconf, jbconf->resync_threshold);
00458    if (!jbobj) {
00459       ast_log(LOG_WARNING, "Failed to create jitterbuffer on channel '%s'\n", chan->name);
00460       return -1;
00461    }
00462 
00463    now = get_now(jb, NULL);
00464    res = jbimpl->put_first(jbobj, frr, now);
00465 
00466    /* The result of putting the first frame should not differ from OK. However, its possible
00467       some implementations (i.e. adaptive's when resynch_threshold is specified) to drop it. */
00468    if (res != JB_IMPL_OK) {
00469       ast_log(LOG_WARNING, "Failed to put first frame in the jitterbuffer on channel '%s'\n", chan->name);
00470       /*
00471       jbimpl->destroy(jbobj);
00472       return -1;
00473       */
00474    }
00475 
00476    /* Init next */
00477    jb->next = jbimpl->next(jbobj);
00478 
00479    /* Init last format for a first time. */
00480    jb->last_format = frr->subclass;
00481 
00482    /* Create a frame log file */
00483    if (ast_test_flag(jbconf, AST_JB_LOG)) {
00484       char safe_logfile[30] = "/tmp/logfile-XXXXXX";
00485       int safe_fd;
00486       snprintf(name2, sizeof(name2), "%s", chan->name);
00487       if ((tmp = strchr(name2, '/'))) {
00488          *tmp = '#';
00489       }
00490 
00491       bridged = ast_bridged_channel(chan);
00492       /* We should always have bridged chan if a jitterbuffer is in use */
00493       ast_assert(bridged != NULL);
00494 
00495       snprintf(name1, sizeof(name1), "%s", bridged->name);
00496       if ((tmp = strchr(name1, '/'))) {
00497          *tmp = '#';
00498       }
00499 
00500       snprintf(logfile_pathname, sizeof(logfile_pathname),
00501          "/tmp/ast_%s_jb_%s--%s.log", jbimpl->name, name1, name2);
00502       unlink(logfile_pathname);
00503       safe_fd = mkstemp(safe_logfile);
00504       if (safe_fd < 0 || link(safe_logfile, logfile_pathname) || unlink(safe_logfile) || !(jb->logfile = fdopen(safe_fd, "w+b"))) {
00505          ast_log(LOG_ERROR, "Failed to create frame log file with pathname '%s': %s\n", logfile_pathname, strerror(errno));
00506          jb->logfile = NULL;
00507          if (safe_fd > -1) {
00508             close(safe_fd);
00509          }
00510       }
00511 
00512       if (res == JB_IMPL_OK) {
00513          jb_framelog("JB_PUT_FIRST {now=%ld}: Queued frame with ts=%ld and len=%ld\n",
00514             now, frr->ts, frr->len);
00515       } else {
00516          jb_framelog("JB_PUT_FIRST {now=%ld}: Dropped frame with ts=%ld and len=%ld\n",
00517             now, frr->ts, frr->len);
00518       }
00519    }
00520 
00521    ast_verb(3, "%s jitterbuffer created on channel %s\n", jbimpl->name, chan->name);
00522 
00523    /* Free the frame if it has not been queued in the jb */
00524    if (res != JB_IMPL_OK) {
00525       ast_frfree(frr);
00526    }
00527 
00528    return 0;
00529 }
00530 
00531 
00532 void ast_jb_destroy(struct ast_channel *chan)
00533 {
00534    struct ast_jb *jb = &chan->jb;
00535    struct ast_jb_impl *jbimpl = jb->impl;
00536    void *jbobj = jb->jbobj;
00537    struct ast_frame *f;
00538 
00539    if (jb->logfile) {
00540       fclose(jb->logfile);
00541       jb->logfile = NULL;
00542    }
00543 
00544    if (ast_test_flag(jb, JB_CREATED)) {
00545       /* Remove and free all frames still queued in jb */
00546       while (jbimpl->remove(jbobj, &f) == JB_IMPL_OK) {
00547          ast_frfree(f);
00548       }
00549 
00550       jbimpl->destroy(jbobj);
00551       jb->jbobj = NULL;
00552 
00553       ast_clear_flag(jb, JB_CREATED);
00554 
00555       ast_verb(3, "%s jitterbuffer destroyed on channel %s\n", jbimpl->name, chan->name);
00556    }
00557 }
00558 
00559 
00560 static long get_now(struct ast_jb *jb, struct timeval *when)
00561 {
00562    struct timeval now;
00563 
00564    if (!when) {
00565       when = &now;
00566       gettimeofday(when, NULL);
00567    }
00568 
00569    return ast_tvdiff_ms(*when, jb->timebase);
00570 }
00571 
00572 
00573 int ast_jb_read_conf(struct ast_jb_conf *conf, const char *varname, const char *value)
00574 {
00575    int prefixlen = sizeof(AST_JB_CONF_PREFIX) - 1;
00576    const char *name;
00577    int tmp;
00578 
00579    if (strncasecmp(AST_JB_CONF_PREFIX, varname, prefixlen)) {
00580       return -1;
00581    }
00582 
00583    name = varname + prefixlen;
00584 
00585    if (!strcasecmp(name, AST_JB_CONF_ENABLE)) {
00586       ast_set2_flag(conf, ast_true(value), AST_JB_ENABLED);
00587    } else if (!strcasecmp(name, AST_JB_CONF_FORCE)) {
00588       ast_set2_flag(conf, ast_true(value), AST_JB_FORCED);
00589    } else if (!strcasecmp(name, AST_JB_CONF_MAX_SIZE)) {
00590       if ((tmp = atoi(value)) > 0)
00591          conf->max_size = tmp;
00592    } else if (!strcasecmp(name, AST_JB_CONF_RESYNCH_THRESHOLD)) {
00593       if ((tmp = atoi(value)) > 0)
00594          conf->resync_threshold = tmp;
00595    } else if (!strcasecmp(name, AST_JB_CONF_IMPL)) {
00596       if (!ast_strlen_zero(value))
00597          snprintf(conf->impl, sizeof(conf->impl), "%s", value);
00598    } else if (!strcasecmp(name, AST_JB_CONF_TARGET_EXTRA)) {
00599       if (sscanf(value, "%30d", &tmp) == 1) {
00600          conf->target_extra = tmp;
00601       }
00602    } else if (!strcasecmp(name, AST_JB_CONF_LOG)) {
00603       ast_set2_flag(conf, ast_true(value), AST_JB_LOG);
00604    } else {
00605       return -1;
00606    }
00607 
00608    return 0;
00609 }
00610 
00611 
00612 void ast_jb_configure(struct ast_channel *chan, const struct ast_jb_conf *conf)
00613 {
00614    memcpy(&chan->jb.conf, conf, sizeof(*conf));
00615 }
00616 
00617 
00618 void ast_jb_get_config(const struct ast_channel *chan, struct ast_jb_conf *conf)
00619 {
00620    memcpy(conf, &chan->jb.conf, sizeof(*conf));
00621 }
00622 
00623 void ast_jb_empty_and_reset(struct ast_channel *c0, struct ast_channel *c1)
00624 {
00625    struct ast_jb *jb0 = &c0->jb;
00626    struct ast_jb *jb1 = &c1->jb;
00627    int c0_use_jb = ast_test_flag(jb0, JB_USE);
00628    int c0_jb_is_created = ast_test_flag(jb0, JB_CREATED);
00629    int c1_use_jb = ast_test_flag(jb1, JB_USE);
00630    int c1_jb_is_created = ast_test_flag(jb1, JB_CREATED);
00631 
00632    if (c0_use_jb && c0_jb_is_created && jb0->impl->empty_and_reset) {
00633       jb0->impl->empty_and_reset(jb0->jbobj);
00634    }
00635 
00636    if (c1_use_jb && c1_jb_is_created && jb1->impl->empty_and_reset) {
00637       jb1->impl->empty_and_reset(jb1->jbobj);
00638    }
00639 }
00640 
00641 /* Implementation functions */
00642 
00643 /* fixed */
00644 static void * jb_create_fixed(struct ast_jb_conf *general_config, long resynch_threshold)
00645 {
00646    struct fixed_jb_conf conf;
00647 
00648    conf.jbsize = general_config->max_size;
00649    conf.resync_threshold = resynch_threshold;
00650 
00651    return fixed_jb_new(&conf);
00652 }
00653 
00654 static void jb_destroy_fixed(void *jb)
00655 {
00656    struct fixed_jb *fixedjb = (struct fixed_jb *) jb;
00657 
00658    /* destroy the jb */
00659    fixed_jb_destroy(fixedjb);
00660 }
00661 
00662 
00663 static int jb_put_first_fixed(void *jb, struct ast_frame *fin, long now)
00664 {
00665    struct fixed_jb *fixedjb = (struct fixed_jb *) jb;
00666    int res;
00667 
00668    res = fixed_jb_put_first(fixedjb, fin, fin->len, fin->ts, now);
00669 
00670    return fixed_to_abstract_code[res];
00671 }
00672 
00673 
00674 static int jb_put_fixed(void *jb, struct ast_frame *fin, long now)
00675 {
00676    struct fixed_jb *fixedjb = (struct fixed_jb *) jb;
00677    int res;
00678 
00679    res = fixed_jb_put(fixedjb, fin, fin->len, fin->ts, now);
00680 
00681    return fixed_to_abstract_code[res];
00682 }
00683 
00684 
00685 static int jb_get_fixed(void *jb, struct ast_frame **fout, long now, long interpl)
00686 {
00687    struct fixed_jb *fixedjb = (struct fixed_jb *) jb;
00688    struct fixed_jb_frame frame;
00689    int res;
00690 
00691    res = fixed_jb_get(fixedjb, &frame, now, interpl);
00692    *fout = frame.data;
00693 
00694    return fixed_to_abstract_code[res];
00695 }
00696 
00697 
00698 static long jb_next_fixed(void *jb)
00699 {
00700    struct fixed_jb *fixedjb = (struct fixed_jb *) jb;
00701 
00702    return fixed_jb_next(fixedjb);
00703 }
00704 
00705 
00706 static int jb_remove_fixed(void *jb, struct ast_frame **fout)
00707 {
00708    struct fixed_jb *fixedjb = (struct fixed_jb *) jb;
00709    struct fixed_jb_frame frame;
00710    int res;
00711 
00712    res = fixed_jb_remove(fixedjb, &frame);
00713    *fout = frame.data;
00714 
00715    return fixed_to_abstract_code[res];
00716 }
00717 
00718 
00719 static void jb_force_resynch_fixed(void *jb)
00720 {
00721    struct fixed_jb *fixedjb = (struct fixed_jb *) jb;
00722 
00723    fixed_jb_set_force_resynch(fixedjb);
00724 }
00725 
00726 static void jb_empty_and_reset_fixed(void *jb)
00727 {
00728    struct fixed_jb *fixedjb = jb;
00729    struct fixed_jb_frame f;
00730 
00731    while (fixed_jb_remove(fixedjb, &f) == FIXED_JB_OK) {
00732       ast_frfree(f.data);
00733    }
00734 }
00735 
00736 /* adaptive */
00737 
00738 static void *jb_create_adaptive(struct ast_jb_conf *general_config, long resynch_threshold)
00739 {
00740    jb_conf jbconf;
00741    jitterbuf *adaptivejb;
00742 
00743    adaptivejb = jb_new();
00744    if (adaptivejb) {
00745       jbconf.max_jitterbuf = general_config->max_size;
00746       jbconf.resync_threshold = general_config->resync_threshold;
00747       jbconf.max_contig_interp = 10;
00748       jbconf.target_extra = general_config->target_extra;
00749       jb_setconf(adaptivejb, &jbconf);
00750    }
00751 
00752    return adaptivejb;
00753 }
00754 
00755 
00756 static void jb_destroy_adaptive(void *jb)
00757 {
00758    jitterbuf *adaptivejb = (jitterbuf *) jb;
00759 
00760    jb_destroy(adaptivejb);
00761 }
00762 
00763 
00764 static int jb_put_first_adaptive(void *jb, struct ast_frame *fin, long now)
00765 {
00766    jitterbuf *adaptivejb = (jitterbuf *) jb;
00767 
00768    /* Initialize the offset to that of the first frame's timestamp */
00769    adaptivejb->info.resync_offset = fin->ts;
00770 
00771    return jb_put_adaptive(jb, fin, now);
00772 }
00773 
00774 
00775 static int jb_put_adaptive(void *jb, struct ast_frame *fin, long now)
00776 {
00777    jitterbuf *adaptivejb = (jitterbuf *) jb;
00778    int res;
00779 
00780    res = jb_put(adaptivejb, fin, JB_TYPE_VOICE, fin->len, fin->ts, now);
00781 
00782    return adaptive_to_abstract_code[res];
00783 }
00784 
00785 
00786 static int jb_get_adaptive(void *jb, struct ast_frame **fout, long now, long interpl)
00787 {
00788    jitterbuf *adaptivejb = (jitterbuf *) jb;
00789    jb_frame frame;
00790    int res;
00791 
00792    res = jb_get(adaptivejb, &frame, now, interpl);
00793    *fout = frame.data;
00794 
00795    return adaptive_to_abstract_code[res];
00796 }
00797 
00798 
00799 static long jb_next_adaptive(void *jb)
00800 {
00801    jitterbuf *adaptivejb = (jitterbuf *) jb;
00802 
00803    return jb_next(adaptivejb);
00804 }
00805 
00806 
00807 static int jb_remove_adaptive(void *jb, struct ast_frame **fout)
00808 {
00809    jitterbuf *adaptivejb = (jitterbuf *) jb;
00810    jb_frame frame;
00811    int res;
00812 
00813    res = jb_getall(adaptivejb, &frame);
00814    *fout = frame.data;
00815 
00816    return adaptive_to_abstract_code[res];
00817 }
00818 
00819 
00820 static void jb_force_resynch_adaptive(void *jb)
00821 {
00822 }
00823 
00824 static void jb_empty_and_reset_adaptive(void *jb)
00825 {
00826    jitterbuf *adaptivejb = jb;
00827    jb_frame f;
00828 
00829    while (jb_getall(adaptivejb, &f) == JB_OK) {
00830       ast_frfree(f.data);
00831    }
00832 
00833    jb_reset(adaptivejb);
00834 }