Mon Oct 8 12:39:01 2012

Asterisk developer's documentation


codec_dahdi.c

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * DAHDI native transcoding support
00005  *
00006  * Copyright (C) 1999 - 2008, Digium, Inc.
00007  *
00008  * Mark Spencer <markster@digium.com>
00009  * Kevin P. Fleming <kpfleming@digium.com>
00010  *
00011  * See http://www.asterisk.org for more information about
00012  * the Asterisk project. Please do not directly contact
00013  * any of the maintainers of this project for assistance;
00014  * the project provides a web site, mailing lists and IRC
00015  * channels for your use.
00016  *
00017  * This program is free software, distributed under the terms of
00018  * the GNU General Public License Version 2. See the LICENSE file
00019  * at the top of the source tree.
00020  */
00021 
00022 /*! \file
00023  *
00024  * \brief Translate between various formats natively through DAHDI transcoding
00025  *
00026  * \ingroup codecs
00027  */
00028 
00029 /*** MODULEINFO
00030    <support_level>core</support_level>
00031    <depend>dahdi</depend>
00032  ***/
00033 
00034 #include "asterisk.h"
00035 
00036 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 365989 $")
00037 
00038 #include <fcntl.h>
00039 #include <netinet/in.h>
00040 #include <sys/ioctl.h>
00041 #include <sys/mman.h>
00042 #include <sys/poll.h>
00043 #include <dahdi/user.h>
00044 
00045 #include "asterisk/lock.h"
00046 #include "asterisk/translate.h"
00047 #include "asterisk/config.h"
00048 #include "asterisk/module.h"
00049 #include "asterisk/cli.h"
00050 #include "asterisk/channel.h"
00051 #include "asterisk/utils.h"
00052 #include "asterisk/linkedlists.h"
00053 #include "asterisk/ulaw.h"
00054 
00055 #define BUFFER_SIZE 8000
00056 
00057 #define G723_SAMPLES 240
00058 #define G729_SAMPLES 160
00059 #define ULAW_SAMPLES 160
00060 
00061 static struct channel_usage {
00062    int total;
00063    int encoders;
00064    int decoders;
00065 } channels;
00066 
00067 static char *handle_cli_transcoder_show(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);
00068 
00069 static struct ast_cli_entry cli[] = {
00070    AST_CLI_DEFINE(handle_cli_transcoder_show, "Display DAHDI transcoder utilization.")
00071 };
00072 
00073 struct format_map {
00074    unsigned int map[32][32];
00075 };
00076 
00077 static struct format_map global_format_map = { { { 0 } } };
00078 
00079 struct translator {
00080    struct ast_translator t;
00081    AST_LIST_ENTRY(translator) entry;
00082 };
00083 
00084 static AST_LIST_HEAD_STATIC(translators, translator);
00085 
00086 struct codec_dahdi_pvt {
00087    int fd;
00088    struct dahdi_transcoder_formats fmts;
00089    unsigned int softslin:1;
00090    unsigned int fake:2;
00091    uint16_t required_samples;
00092    uint16_t samples_in_buffer;
00093    uint16_t samples_written_to_hardware;
00094    uint8_t ulaw_buffer[1024];
00095 };
00096 
00097 /* Only used by a decoder */
00098 static int ulawtolin(struct ast_trans_pvt *pvt, int samples)
00099 {
00100    struct codec_dahdi_pvt *dahdip = pvt->pvt;
00101    int i = samples;
00102    uint8_t *src = &dahdip->ulaw_buffer[0];
00103    int16_t *dst = pvt->outbuf.i16 + pvt->datalen;
00104 
00105    /* convert and copy in outbuf */
00106    while (i--) {
00107       *dst++ = AST_MULAW(*src++);
00108    }
00109 
00110    return 0;
00111 }
00112 
00113 /* Only used by an encoder. */
00114 static int lintoulaw(struct ast_trans_pvt *pvt, struct ast_frame *f)
00115 {
00116    struct codec_dahdi_pvt *dahdip = pvt->pvt;
00117    int i = f->samples;
00118    uint8_t *dst = &dahdip->ulaw_buffer[dahdip->samples_in_buffer];
00119    int16_t *src = f->data.ptr;
00120 
00121    if (dahdip->samples_in_buffer + i > sizeof(dahdip->ulaw_buffer)) {
00122       ast_log(LOG_ERROR, "Out of buffer space!\n");
00123       return -i;
00124    }
00125 
00126    while (i--) {
00127       *dst++ = AST_LIN2MU(*src++);
00128    }
00129 
00130    dahdip->samples_in_buffer += f->samples;
00131    return 0;
00132 }
00133 
00134 static char *handle_cli_transcoder_show(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
00135 {
00136    struct channel_usage copy;
00137 
00138    switch (cmd) {
00139    case CLI_INIT:
00140       e->command = "transcoder show";
00141       e->usage =
00142          "Usage: transcoder show\n"
00143          "       Displays channel utilization of DAHDI transcoder(s).\n";
00144       return NULL;
00145    case CLI_GENERATE:
00146       return NULL;
00147    }
00148 
00149    if (a->argc != 2)
00150       return CLI_SHOWUSAGE;
00151 
00152    copy = channels;
00153 
00154    if (copy.total == 0)
00155       ast_cli(a->fd, "No DAHDI transcoders found.\n");
00156    else
00157       ast_cli(a->fd, "%d/%d encoders/decoders of %d channels are in use.\n", copy.encoders, copy.decoders, copy.total);
00158 
00159    return CLI_SUCCESS;
00160 }
00161 
00162 static void dahdi_write_frame(struct codec_dahdi_pvt *dahdip, const uint8_t *buffer, const ssize_t count)
00163 {
00164    int res;
00165    if (!count) return;
00166    res = write(dahdip->fd, buffer, count);
00167    if (option_verbose > 10) {
00168       if (-1 == res) {
00169          ast_log(LOG_ERROR, "Failed to write to transcoder: %s\n", strerror(errno));
00170       }
00171       if (count != res) {
00172          ast_log(LOG_ERROR, "Requested write of %zd bytes, but only wrote %d bytes.\n", count, res);
00173       }
00174    }
00175 }
00176 
00177 static int dahdi_encoder_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
00178 {
00179    struct codec_dahdi_pvt *dahdip = pvt->pvt;
00180 
00181    if (!f->subclass.codec) {
00182       /* We're just faking a return for calculation purposes. */
00183       dahdip->fake = 2;
00184       pvt->samples = f->samples;
00185       return 0;
00186    }
00187 
00188    /* Buffer up the packets and send them to the hardware if we
00189     * have enough samples set up. */
00190    if (dahdip->softslin) {
00191       if (lintoulaw(pvt, f)) {
00192           return -1;
00193       }
00194    } else {
00195       /* NOTE:  If softslin support is not needed, and the sample
00196        * size is equal to the required sample size, we wouldn't
00197        * need this copy operation.  But at the time this was
00198        * written, only softslin is supported. */
00199       if (dahdip->samples_in_buffer + f->samples > sizeof(dahdip->ulaw_buffer)) {
00200          ast_log(LOG_ERROR, "Out of buffer space.\n");
00201          return -1;
00202       }
00203       memcpy(&dahdip->ulaw_buffer[dahdip->samples_in_buffer], f->data.ptr, f->samples);
00204       dahdip->samples_in_buffer += f->samples;
00205    }
00206 
00207    while (dahdip->samples_in_buffer >= dahdip->required_samples) {
00208       dahdi_write_frame(dahdip, dahdip->ulaw_buffer, dahdip->required_samples);
00209       dahdip->samples_written_to_hardware += dahdip->required_samples;
00210       dahdip->samples_in_buffer -= dahdip->required_samples;
00211       if (dahdip->samples_in_buffer) {
00212          /* Shift any remaining bytes down. */
00213          memmove(dahdip->ulaw_buffer, &dahdip->ulaw_buffer[dahdip->required_samples],
00214             dahdip->samples_in_buffer);
00215       }
00216    }
00217    pvt->samples += f->samples;
00218    pvt->datalen = 0;
00219    return -1;
00220 }
00221 
00222 static void dahdi_wait_for_packet(int fd)
00223 {
00224    struct pollfd p = {0};
00225    p.fd = fd;
00226    p.events = POLLIN;
00227    poll(&p, 1, 10);
00228 }
00229 
00230 static struct ast_frame *dahdi_encoder_frameout(struct ast_trans_pvt *pvt)
00231 {
00232    struct codec_dahdi_pvt *dahdip = pvt->pvt;
00233    int res;
00234 
00235    if (2 == dahdip->fake) {
00236       dahdip->fake = 1;
00237       pvt->f.frametype = AST_FRAME_VOICE;
00238       pvt->f.subclass.codec = 0;
00239       pvt->f.samples = dahdip->required_samples;
00240       pvt->f.data.ptr = NULL;
00241       pvt->f.offset = 0;
00242       pvt->f.datalen = 0;
00243       pvt->f.mallocd = 0;
00244       pvt->samples = 0;
00245 
00246       return ast_frisolate(&pvt->f);
00247 
00248    } else if (1 == dahdip->fake) {
00249       dahdip->fake = 0;
00250       return NULL;
00251    }
00252 
00253    if (dahdip->samples_written_to_hardware >= dahdip->required_samples) {
00254       dahdi_wait_for_packet(dahdip->fd);
00255    }
00256 
00257    res = read(dahdip->fd, pvt->outbuf.c + pvt->datalen, pvt->t->buf_size - pvt->datalen);
00258    if (-1 == res) {
00259       if (EWOULDBLOCK == errno) {
00260          /* Nothing waiting... */
00261          return NULL;
00262       } else {
00263          ast_log(LOG_ERROR, "Failed to read from transcoder: %s\n", strerror(errno));
00264          return NULL;
00265       }
00266    } else {
00267       pvt->f.datalen = res;
00268       pvt->f.frametype = AST_FRAME_VOICE;
00269       pvt->f.subclass.codec = 1 <<  (pvt->t->dstfmt);
00270       pvt->f.mallocd = 0;
00271       pvt->f.offset = AST_FRIENDLY_OFFSET;
00272       pvt->f.src = pvt->t->name;
00273       pvt->f.data.ptr = pvt->outbuf.c;
00274       pvt->f.samples = ast_codec_get_samples(&pvt->f);
00275 
00276       dahdip->samples_written_to_hardware =
00277         (dahdip->samples_written_to_hardware >= pvt->f.samples) ?
00278            dahdip->samples_written_to_hardware - pvt->f.samples : 0;
00279 
00280       pvt->samples = 0;
00281       pvt->datalen = 0;
00282       return ast_frisolate(&pvt->f);
00283    }
00284 
00285    /* Shouldn't get here... */
00286    return NULL;
00287 }
00288 
00289 static int dahdi_decoder_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
00290 {
00291    struct codec_dahdi_pvt *dahdip = pvt->pvt;
00292 
00293    if (!f->subclass.codec) {
00294       /* We're just faking a return for calculation purposes. */
00295       dahdip->fake = 2;
00296       pvt->samples = f->samples;
00297       return 0;
00298    }
00299 
00300    if (!f->datalen) {
00301       if (f->samples != dahdip->required_samples) {
00302          ast_log(LOG_ERROR, "%d != %d %d\n", f->samples, dahdip->required_samples, f->datalen);
00303       }
00304    }
00305    dahdi_write_frame(dahdip, f->data.ptr, f->datalen);
00306    dahdip->samples_written_to_hardware += f->samples;
00307    pvt->samples += f->samples;
00308    pvt->datalen = 0;
00309    return -1;
00310 }
00311 
00312 static struct ast_frame *dahdi_decoder_frameout(struct ast_trans_pvt *pvt)
00313 {
00314    int res;
00315    struct codec_dahdi_pvt *dahdip = pvt->pvt;
00316 
00317    if (2 == dahdip->fake) {
00318       dahdip->fake = 1;
00319       pvt->f.frametype = AST_FRAME_VOICE;
00320       pvt->f.subclass.codec = 0;
00321       pvt->f.samples = dahdip->required_samples;
00322       pvt->f.data.ptr = NULL;
00323       pvt->f.offset = 0;
00324       pvt->f.datalen = 0;
00325       pvt->f.mallocd = 0;
00326       pvt->samples = 0;
00327       return ast_frisolate(&pvt->f);
00328    } else if (1 == dahdip->fake) {
00329       pvt->samples = 0;
00330       dahdip->fake = 0;
00331       return NULL;
00332    }
00333 
00334    if (dahdip->samples_written_to_hardware >= ULAW_SAMPLES) {
00335       dahdi_wait_for_packet(dahdip->fd);
00336    }
00337 
00338    /* Let's check to see if there is a new frame for us.... */
00339    if (dahdip->softslin) {
00340       res = read(dahdip->fd, dahdip->ulaw_buffer, sizeof(dahdip->ulaw_buffer));
00341    } else {
00342       res = read(dahdip->fd, pvt->outbuf.c + pvt->datalen, pvt->t->buf_size - pvt->datalen);
00343    }
00344 
00345    if (-1 == res) {
00346       if (EWOULDBLOCK == errno) {
00347          /* Nothing waiting... */
00348          return NULL;
00349       } else {
00350          ast_log(LOG_ERROR, "Failed to read from transcoder: %s\n", strerror(errno));
00351          return NULL;
00352       }
00353    } else {
00354       if (dahdip->softslin) {
00355          ulawtolin(pvt, res);
00356          pvt->f.datalen = res * 2;
00357       } else {
00358          pvt->f.datalen = res;
00359       }
00360       pvt->datalen = 0;
00361       pvt->f.frametype = AST_FRAME_VOICE;
00362       pvt->f.subclass.codec = 1 <<  (pvt->t->dstfmt);
00363       pvt->f.mallocd = 0;
00364       pvt->f.offset = AST_FRIENDLY_OFFSET;
00365       pvt->f.src = pvt->t->name;
00366       pvt->f.data.ptr = pvt->outbuf.c;
00367       pvt->f.samples = res;
00368       pvt->samples = 0;
00369       dahdip->samples_written_to_hardware =
00370          (dahdip->samples_written_to_hardware >= res) ?
00371                  dahdip->samples_written_to_hardware - res : 0;
00372 
00373       return ast_frisolate(&pvt->f);
00374    }
00375 
00376    /* Shouldn't get here... */
00377    return NULL;
00378 }
00379 
00380 
00381 static void dahdi_destroy(struct ast_trans_pvt *pvt)
00382 {
00383    struct codec_dahdi_pvt *dahdip = pvt->pvt;
00384 
00385    switch (dahdip->fmts.dstfmt) {
00386    case AST_FORMAT_G729A:
00387    case AST_FORMAT_G723_1:
00388       ast_atomic_fetchadd_int(&channels.encoders, -1);
00389       break;
00390    default:
00391       ast_atomic_fetchadd_int(&channels.decoders, -1);
00392       break;
00393    }
00394 
00395    close(dahdip->fd);
00396 }
00397 
00398 static int dahdi_translate(struct ast_trans_pvt *pvt, int dest, int source)
00399 {
00400    /* Request translation through zap if possible */
00401    int fd;
00402    struct codec_dahdi_pvt *dahdip = pvt->pvt;
00403    int flags;
00404    int tried_once = 0;
00405    const char *dev_filename = "/dev/dahdi/transcode";
00406 
00407    if ((fd = open(dev_filename, O_RDWR)) < 0) {
00408       ast_log(LOG_ERROR, "Failed to open %s: %s\n", dev_filename, strerror(errno));
00409       return -1;
00410    }
00411 
00412    dahdip->fmts.srcfmt = (1 << source);
00413    dahdip->fmts.dstfmt = (1 << dest);
00414 
00415    ast_debug(1, "Opening transcoder channel from %d to %d.\n", source, dest);
00416 
00417 retry:
00418    if (ioctl(fd, DAHDI_TC_ALLOCATE, &dahdip->fmts)) {
00419       if ((ENODEV == errno) && !tried_once) {
00420          /* We requested to translate to/from an unsupported
00421           * format.  Most likely this is because signed linear
00422           * was not supported by any hardware devices even
00423           * though this module always registers signed linear
00424           * support. In this case we'll retry, requesting
00425           * support for ULAW instead of signed linear and then
00426           * we'll just convert from ulaw to signed linear in
00427           * software. */
00428          if (AST_FORMAT_SLINEAR == dahdip->fmts.srcfmt) {
00429             ast_debug(1, "Using soft_slin support on source\n");
00430             dahdip->softslin = 1;
00431             dahdip->fmts.srcfmt = AST_FORMAT_ULAW;
00432          } else if (AST_FORMAT_SLINEAR == dahdip->fmts.dstfmt) {
00433             ast_debug(1, "Using soft_slin support on destination\n");
00434             dahdip->softslin = 1;
00435             dahdip->fmts.dstfmt = AST_FORMAT_ULAW;
00436          }
00437          tried_once = 1;
00438          goto retry;
00439       }
00440       ast_log(LOG_ERROR, "Unable to attach to transcoder: %s\n", strerror(errno));
00441       close(fd);
00442 
00443       return -1;
00444    }
00445 
00446    flags = fcntl(fd, F_GETFL);
00447    if (flags > - 1) {
00448       if (fcntl(fd, F_SETFL, flags | O_NONBLOCK))
00449          ast_log(LOG_WARNING, "Could not set non-block mode!\n");
00450    }
00451 
00452    dahdip->fd = fd;
00453 
00454    dahdip->required_samples = ((dahdip->fmts.dstfmt|dahdip->fmts.srcfmt)&AST_FORMAT_G723_1) ? G723_SAMPLES : G729_SAMPLES;
00455 
00456    switch (dahdip->fmts.dstfmt) {
00457    case AST_FORMAT_G729A:
00458       ast_atomic_fetchadd_int(&channels.encoders, +1);
00459       break;
00460    case AST_FORMAT_G723_1:
00461       ast_atomic_fetchadd_int(&channels.encoders, +1);
00462       break;
00463    default:
00464       ast_atomic_fetchadd_int(&channels.decoders, +1);
00465       break;
00466    }
00467 
00468    return 0;
00469 }
00470 
00471 static int dahdi_new(struct ast_trans_pvt *pvt)
00472 {
00473    return dahdi_translate(pvt, pvt->t->dstfmt, pvt->t->srcfmt);
00474 }
00475 
00476 static struct ast_frame *fakesrc_sample(void)
00477 {
00478    /* Don't bother really trying to test hardware ones. */
00479    static struct ast_frame f = {
00480       .frametype = AST_FRAME_VOICE,
00481       .samples = 160,
00482       .src = __PRETTY_FUNCTION__
00483    };
00484 
00485    return &f;
00486 }
00487 
00488 static int is_encoder(struct translator *zt)
00489 {
00490    if (zt->t.srcfmt&(AST_FORMAT_ULAW|AST_FORMAT_ALAW|AST_FORMAT_SLINEAR)) {
00491       return 1;
00492    } else {
00493       return 0;
00494    }
00495 }
00496 
00497 static int register_translator(int dst, int src)
00498 {
00499    struct translator *zt;
00500    int res;
00501 
00502    if (!(zt = ast_calloc(1, sizeof(*zt)))) {
00503       return -1;
00504    }
00505 
00506    snprintf((char *) (zt->t.name), sizeof(zt->t.name), "zap%sto%s",
00507        ast_getformatname((1 << src)), ast_getformatname((1 << dst)));
00508    zt->t.srcfmt = (1 << src);
00509    zt->t.dstfmt = (1 << dst);
00510    zt->t.buf_size = BUFFER_SIZE;
00511    if (is_encoder(zt)) {
00512       zt->t.framein = dahdi_encoder_framein;
00513       zt->t.frameout = dahdi_encoder_frameout;
00514    } else {
00515       zt->t.framein = dahdi_decoder_framein;
00516       zt->t.frameout = dahdi_decoder_frameout;
00517    }
00518    zt->t.destroy = dahdi_destroy;
00519    zt->t.buffer_samples = 0;
00520    zt->t.newpvt = dahdi_new;
00521    zt->t.sample = fakesrc_sample;
00522    zt->t.native_plc = 0;
00523 
00524    zt->t.desc_size = sizeof(struct codec_dahdi_pvt);
00525    if ((res = ast_register_translator(&zt->t))) {
00526       ast_free(zt);
00527       return -1;
00528    }
00529 
00530    AST_LIST_LOCK(&translators);
00531    AST_LIST_INSERT_HEAD(&translators, zt, entry);
00532    AST_LIST_UNLOCK(&translators);
00533 
00534    global_format_map.map[dst][src] = 1;
00535 
00536    return res;
00537 }
00538 
00539 static void drop_translator(int dst, int src)
00540 {
00541    struct translator *cur;
00542 
00543    AST_LIST_LOCK(&translators);
00544    AST_LIST_TRAVERSE_SAFE_BEGIN(&translators, cur, entry) {
00545       if (cur->t.srcfmt != src)
00546          continue;
00547 
00548       if (cur->t.dstfmt != dst)
00549          continue;
00550 
00551       AST_LIST_REMOVE_CURRENT(entry);
00552       ast_unregister_translator(&cur->t);
00553       ast_free(cur);
00554       global_format_map.map[dst][src] = 0;
00555       break;
00556    }
00557    AST_LIST_TRAVERSE_SAFE_END;
00558    AST_LIST_UNLOCK(&translators);
00559 }
00560 
00561 static void unregister_translators(void)
00562 {
00563    struct translator *cur;
00564 
00565    AST_LIST_LOCK(&translators);
00566    while ((cur = AST_LIST_REMOVE_HEAD(&translators, entry))) {
00567       ast_unregister_translator(&cur->t);
00568       ast_free(cur);
00569    }
00570    AST_LIST_UNLOCK(&translators);
00571 }
00572 
00573 static void build_translators(struct format_map *map, unsigned int dstfmts, unsigned int srcfmts)
00574 {
00575    unsigned int src, dst;
00576 
00577    for (src = 0; src < 32; src++) {
00578       for (dst = 0; dst < 32; dst++) {
00579          if (!(srcfmts & (1 << src)))
00580             continue;
00581 
00582          if (!(dstfmts & (1 << dst)))
00583             continue;
00584 
00585          if (global_format_map.map[dst][src])
00586             continue;
00587 
00588          if (!register_translator(dst, src))
00589             map->map[dst][src] = 1;
00590       }
00591    }
00592 }
00593 
00594 static int find_transcoders(void)
00595 {
00596    struct dahdi_transcoder_info info = { 0, };
00597    struct format_map map = { { { 0 } } };
00598    int fd, res;
00599    unsigned int x, y;
00600 
00601    if ((fd = open("/dev/dahdi/transcode", O_RDWR)) < 0) {
00602       ast_log(LOG_ERROR, "Failed to open /dev/dahdi/transcode: %s\n", strerror(errno));
00603       return 0;
00604    }
00605 
00606    for (info.tcnum = 0; !(res = ioctl(fd, DAHDI_TC_GETINFO, &info)); info.tcnum++) {
00607       if (option_verbose > 1)
00608          ast_verbose(VERBOSE_PREFIX_2 "Found transcoder '%s'.\n", info.name);
00609 
00610       /* Complex codecs need to support signed linear.  If the
00611        * hardware transcoder does not natively support signed linear
00612        * format, we will emulate it in software directly in this
00613        * module. Also, do not allow direct ulaw/alaw to complex
00614        * codec translation, since that will prevent the generic PLC
00615        * functions from working. */
00616       if (info.dstfmts & (AST_FORMAT_ULAW | AST_FORMAT_ALAW)) {
00617          info.dstfmts |= AST_FORMAT_SLINEAR;
00618          info.dstfmts &= ~(AST_FORMAT_ULAW | AST_FORMAT_ALAW);
00619       }
00620       if (info.srcfmts & (AST_FORMAT_ULAW | AST_FORMAT_ALAW)) {
00621          info.srcfmts |= AST_FORMAT_SLINEAR;
00622          info.srcfmts &= ~(AST_FORMAT_ULAW | AST_FORMAT_ALAW);
00623       }
00624 
00625       build_translators(&map, info.dstfmts, info.srcfmts);
00626       ast_atomic_fetchadd_int(&channels.total, info.numchannels / 2);
00627 
00628    }
00629 
00630    close(fd);
00631 
00632    if (!info.tcnum && (option_verbose > 1))
00633       ast_verbose(VERBOSE_PREFIX_2 "No hardware transcoders found.\n");
00634 
00635    for (x = 0; x < 32; x++) {
00636       for (y = 0; y < 32; y++) {
00637          if (!map.map[x][y] && global_format_map.map[x][y])
00638             drop_translator(x, y);
00639       }
00640    }
00641 
00642    return 0;
00643 }
00644 
00645 static int reload(void)
00646 {
00647    return AST_MODULE_LOAD_SUCCESS;
00648 }
00649 
00650 static int unload_module(void)
00651 {
00652    ast_cli_unregister_multiple(cli, ARRAY_LEN(cli));
00653    unregister_translators();
00654 
00655    return 0;
00656 }
00657 
00658 static int load_module(void)
00659 {
00660    ast_ulaw_init();
00661    find_transcoders();
00662    ast_cli_register_multiple(cli, ARRAY_LEN(cli));
00663    return AST_MODULE_LOAD_SUCCESS;
00664 }
00665 
00666 AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT, "Generic DAHDI Transcoder Codec Translator",
00667       .load = load_module,
00668       .unload = unload_module,
00669       .reload = reload,
00670           );

Generated on Mon Oct 8 12:39:01 2012 for Asterisk - The Open Source Telephony Project by  doxygen 1.4.7