Thu Apr 28 2011 17:13:33

Asterisk developer's documentation


codec_dahdi.c

Go to the documentation of this file.
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    <depend>dahdi</depend>
00031  ***/
00032 
00033 #include "asterisk.h"
00034 
00035 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 293969 $")
00036 
00037 #include <fcntl.h>
00038 #include <netinet/in.h>
00039 #include <sys/ioctl.h>
00040 #include <sys/mman.h>
00041 #include <sys/poll.h>
00042 #include <dahdi/user.h>
00043 
00044 #include "asterisk/lock.h"
00045 #include "asterisk/translate.h"
00046 #include "asterisk/config.h"
00047 #include "asterisk/module.h"
00048 #include "asterisk/cli.h"
00049 #include "asterisk/channel.h"
00050 #include "asterisk/utils.h"
00051 #include "asterisk/linkedlists.h"
00052 #include "asterisk/ulaw.h"
00053 
00054 #define BUFFER_SIZE 8000
00055 
00056 #define G723_SAMPLES 240
00057 #define G729_SAMPLES 160
00058 
00059 static struct channel_usage {
00060    int total;
00061    int encoders;
00062    int decoders;
00063 } channels;
00064 
00065 static char *handle_cli_transcoder_show(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a);
00066 
00067 static struct ast_cli_entry cli[] = {
00068    AST_CLI_DEFINE(handle_cli_transcoder_show, "Display DAHDI transcoder utilization.")
00069 };
00070 
00071 struct format_map {
00072    unsigned int map[32][32];
00073 };
00074 
00075 static struct format_map global_format_map = { { { 0 } } };
00076 
00077 struct translator {
00078    struct ast_translator t;
00079    AST_LIST_ENTRY(translator) entry;
00080 };
00081 
00082 static AST_LIST_HEAD_STATIC(translators, translator);
00083 
00084 struct codec_dahdi_pvt {
00085    int fd;
00086    struct dahdi_transcoder_formats fmts;
00087    unsigned int softslin:1;
00088    unsigned int fake:2;
00089    uint16_t required_samples;
00090    uint16_t samples_in_buffer;
00091    uint8_t ulaw_buffer[1024];
00092 };
00093 
00094 /* Only used by a decoder */
00095 static int ulawtolin(struct ast_trans_pvt *pvt, int samples)
00096 {
00097    struct codec_dahdi_pvt *dahdip = pvt->pvt;
00098    int i = samples;
00099    uint8_t *src = &dahdip->ulaw_buffer[0];
00100    int16_t *dst = pvt->outbuf.i16 + pvt->datalen;
00101 
00102    /* convert and copy in outbuf */
00103    while (i--) {
00104       *dst++ = AST_MULAW(*src++);
00105    }
00106 
00107    return 0;
00108 }
00109 
00110 /* Only used by an encoder. */
00111 static int lintoulaw(struct ast_trans_pvt *pvt, struct ast_frame *f)
00112 {
00113    struct codec_dahdi_pvt *dahdip = pvt->pvt;
00114    int i = f->samples;
00115    uint8_t *dst = &dahdip->ulaw_buffer[dahdip->samples_in_buffer];
00116    int16_t *src = f->data.ptr;
00117 
00118    if (dahdip->samples_in_buffer + i > sizeof(dahdip->ulaw_buffer)) {
00119       ast_log(LOG_ERROR, "Out of buffer space!\n");
00120       return -i;
00121    }
00122 
00123    while (i--) {
00124       *dst++ = AST_LIN2MU(*src++);
00125    }
00126 
00127    dahdip->samples_in_buffer += f->samples;
00128    return 0;
00129 }
00130 
00131 static char *handle_cli_transcoder_show(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
00132 {
00133    struct channel_usage copy;
00134 
00135    switch (cmd) {
00136    case CLI_INIT:
00137       e->command = "transcoder show";
00138       e->usage =
00139          "Usage: transcoder show\n"
00140          "       Displays channel utilization of DAHDI transcoder(s).\n";
00141       return NULL;
00142    case CLI_GENERATE:
00143       return NULL;
00144    }
00145 
00146    if (a->argc != 2)
00147       return CLI_SHOWUSAGE;
00148 
00149    copy = channels;
00150 
00151    if (copy.total == 0)
00152       ast_cli(a->fd, "No DAHDI transcoders found.\n");
00153    else
00154       ast_cli(a->fd, "%d/%d encoders/decoders of %d channels are in use.\n", copy.encoders, copy.decoders, copy.total);
00155 
00156    return CLI_SUCCESS;
00157 }
00158 
00159 static void dahdi_write_frame(struct codec_dahdi_pvt *dahdip, const uint8_t *buffer, const ssize_t count)
00160 {
00161    int res;
00162    struct pollfd p = {0};
00163    if (!count) return;
00164    res = write(dahdip->fd, buffer, count);
00165    if (option_verbose > 10) {
00166       if (-1 == res) {
00167          ast_log(LOG_ERROR, "Failed to write to transcoder: %s\n", strerror(errno));
00168       }
00169       if (count != res) {
00170          ast_log(LOG_ERROR, "Requested write of %zd bytes, but only wrote %d bytes.\n", count, res);
00171       }
00172    }
00173    p.fd = dahdip->fd;
00174    p.events = POLLOUT;
00175    res = poll(&p, 1, 50);
00176 }
00177 
00178 static int dahdi_encoder_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
00179 {
00180    struct codec_dahdi_pvt *dahdip = pvt->pvt;
00181 
00182    if (!f->subclass) {
00183       /* We're just faking a return for calculation purposes. */
00184       dahdip->fake = 2;
00185       pvt->samples = f->samples;
00186       return 0;
00187    }
00188 
00189    /* Buffer up the packets and send them to the hardware if we
00190     * have enough samples set up. */
00191    if (dahdip->softslin) {
00192       if (lintoulaw(pvt, f)) {
00193           return -1;
00194       }
00195    } else {
00196       /* NOTE:  If softslin support is not needed, and the sample
00197        * size is equal to the required sample size, we wouldn't
00198        * need this copy operation.  But at the time this was
00199        * written, only softslin is supported. */
00200       if (dahdip->samples_in_buffer + f->samples > sizeof(dahdip->ulaw_buffer)) {
00201          ast_log(LOG_ERROR, "Out of buffer space.\n");
00202          return -1;
00203       }
00204       memcpy(&dahdip->ulaw_buffer[dahdip->samples_in_buffer], f->data.ptr, f->samples);
00205       dahdip->samples_in_buffer += f->samples;
00206    }
00207 
00208    while (dahdip->samples_in_buffer > dahdip->required_samples) {
00209       dahdi_write_frame(dahdip, dahdip->ulaw_buffer, 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 struct ast_frame *dahdi_encoder_frameout(struct ast_trans_pvt *pvt)
00223 {
00224    struct codec_dahdi_pvt *dahdip = pvt->pvt;
00225    int res;
00226 
00227    if (2 == dahdip->fake) {
00228       dahdip->fake = 1;
00229       pvt->f.frametype = AST_FRAME_VOICE;
00230       pvt->f.subclass = 0;
00231       pvt->f.samples = dahdip->required_samples;
00232       pvt->f.data.ptr = NULL;
00233       pvt->f.offset = 0;
00234       pvt->f.datalen = 0;
00235       pvt->f.mallocd = 0;
00236       ast_set_flag(&pvt->f, AST_FRFLAG_FROM_TRANSLATOR);
00237       pvt->samples = 0;
00238 
00239       return &pvt->f;
00240 
00241    } else if (1 == dahdip->fake) {
00242       dahdip->fake = 0;
00243       return NULL;
00244    }
00245 
00246    res = read(dahdip->fd, pvt->outbuf.c + pvt->datalen, pvt->t->buf_size - pvt->datalen);
00247    if (-1 == res) {
00248       if (EWOULDBLOCK == errno) {
00249          /* Nothing waiting... */
00250          return NULL;
00251       } else {
00252          ast_log(LOG_ERROR, "Failed to read from transcoder: %s\n", strerror(errno));
00253          return NULL;
00254       }
00255    } else {
00256       pvt->f.datalen = res;
00257       pvt->f.samples = dahdip->required_samples;
00258       pvt->f.frametype = AST_FRAME_VOICE;
00259       pvt->f.subclass = 1 <<  (pvt->t->dstfmt);
00260       pvt->f.mallocd = 0;
00261       pvt->f.offset = AST_FRIENDLY_OFFSET;
00262       pvt->f.src = pvt->t->name;
00263       pvt->f.data.ptr = pvt->outbuf.c;
00264       ast_set_flag(&pvt->f, AST_FRFLAG_FROM_TRANSLATOR);
00265 
00266       pvt->samples = 0;
00267       pvt->datalen = 0;
00268       return &pvt->f;
00269    }
00270 
00271    /* Shouldn't get here... */
00272    return NULL;
00273 }
00274 
00275 static int dahdi_decoder_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
00276 {
00277    struct codec_dahdi_pvt *dahdip = pvt->pvt;
00278 
00279    if (!f->subclass) {
00280       /* We're just faking a return for calculation purposes. */
00281       dahdip->fake = 2;
00282       pvt->samples = f->samples;
00283       return 0;
00284    }
00285 
00286    if (!f->datalen) {
00287       if (f->samples != dahdip->required_samples) {
00288          ast_log(LOG_ERROR, "%d != %d %d\n", f->samples, dahdip->required_samples, f->datalen);
00289       }
00290    }
00291    dahdi_write_frame(dahdip, f->data.ptr, f->datalen);
00292    pvt->samples += f->samples;
00293    pvt->datalen = 0;
00294    return -1;
00295 }
00296 
00297 static struct ast_frame *dahdi_decoder_frameout(struct ast_trans_pvt *pvt)
00298 {
00299    int res;
00300    struct codec_dahdi_pvt *dahdip = pvt->pvt;
00301 
00302    if (2 == dahdip->fake) {
00303       dahdip->fake = 1;
00304       pvt->f.frametype = AST_FRAME_VOICE;
00305       pvt->f.subclass = 0;
00306       pvt->f.samples = dahdip->required_samples;
00307       pvt->f.data.ptr = NULL;
00308       pvt->f.offset = 0;
00309       pvt->f.datalen = 0;
00310       pvt->f.mallocd = 0;
00311       ast_set_flag(&pvt->f, AST_FRFLAG_FROM_TRANSLATOR);
00312       pvt->samples = 0;
00313       return &pvt->f;
00314    } else if (1 == dahdip->fake) {
00315       pvt->samples = 0;
00316       dahdip->fake = 0;
00317       return NULL;
00318    }
00319 
00320    /* Let's check to see if there is a new frame for us.... */
00321    if (dahdip->softslin) {
00322       res = read(dahdip->fd, dahdip->ulaw_buffer, sizeof(dahdip->ulaw_buffer));
00323    } else {
00324       res = read(dahdip->fd, pvt->outbuf.c + pvt->datalen, pvt->t->buf_size - pvt->datalen);
00325    }
00326 
00327    if (-1 == res) {
00328       if (EWOULDBLOCK == errno) {
00329          /* Nothing waiting... */
00330          return NULL;
00331       } else {
00332          ast_log(LOG_ERROR, "Failed to read from transcoder: %s\n", strerror(errno));
00333          return NULL;
00334       }
00335    } else {
00336       if (dahdip->softslin) {
00337          ulawtolin(pvt, res);
00338          pvt->f.datalen = res * 2;
00339       } else {
00340          pvt->f.datalen = res;
00341       }
00342       pvt->datalen = 0;
00343       pvt->f.frametype = AST_FRAME_VOICE;
00344       pvt->f.subclass = 1 <<  (pvt->t->dstfmt);
00345       pvt->f.mallocd = 0;
00346       pvt->f.offset = AST_FRIENDLY_OFFSET;
00347       pvt->f.src = pvt->t->name;
00348       pvt->f.data.ptr = pvt->outbuf.c;
00349       pvt->f.samples = res;
00350       ast_set_flag(&pvt->f, AST_FRFLAG_FROM_TRANSLATOR);
00351       pvt->samples = 0;
00352 
00353       return &pvt->f;
00354    }
00355 
00356    /* Shouldn't get here... */
00357    return NULL;
00358 }
00359 
00360 
00361 static void dahdi_destroy(struct ast_trans_pvt *pvt)
00362 {
00363    struct codec_dahdi_pvt *dahdip = pvt->pvt;
00364 
00365    switch (dahdip->fmts.dstfmt) {
00366    case AST_FORMAT_G729A:
00367    case AST_FORMAT_G723_1:
00368       ast_atomic_fetchadd_int(&channels.encoders, -1);
00369       break;
00370    default:
00371       ast_atomic_fetchadd_int(&channels.decoders, -1);
00372       break;
00373    }
00374 
00375    close(dahdip->fd);
00376 }
00377 
00378 static int dahdi_translate(struct ast_trans_pvt *pvt, int dest, int source)
00379 {
00380    /* Request translation through zap if possible */
00381    int fd;
00382    struct codec_dahdi_pvt *dahdip = pvt->pvt;
00383    int flags;
00384    int tried_once = 0;
00385    const char *dev_filename = "/dev/dahdi/transcode";
00386 
00387    if ((fd = open(dev_filename, O_RDWR)) < 0) {
00388       ast_log(LOG_ERROR, "Failed to open %s: %s\n", dev_filename, strerror(errno));
00389       return -1;
00390    }
00391 
00392    dahdip->fmts.srcfmt = (1 << source);
00393    dahdip->fmts.dstfmt = (1 << dest);
00394 
00395    ast_debug(1, "Opening transcoder channel from %d to %d.\n", source, dest);
00396 
00397 retry:
00398    if (ioctl(fd, DAHDI_TC_ALLOCATE, &dahdip->fmts)) {
00399       if ((ENODEV == errno) && !tried_once) {
00400          /* We requested to translate to/from an unsupported
00401           * format.  Most likely this is because signed linear
00402           * was not supported by any hardware devices even
00403           * though this module always registers signed linear
00404           * support. In this case we'll retry, requesting
00405           * support for ULAW instead of signed linear and then
00406           * we'll just convert from ulaw to signed linear in
00407           * software. */
00408          if (AST_FORMAT_SLINEAR == dahdip->fmts.srcfmt) {
00409             ast_debug(1, "Using soft_slin support on source\n");
00410             dahdip->softslin = 1;
00411             dahdip->fmts.srcfmt = AST_FORMAT_ULAW;
00412          } else if (AST_FORMAT_SLINEAR == dahdip->fmts.dstfmt) {
00413             ast_debug(1, "Using soft_slin support on destination\n");
00414             dahdip->softslin = 1;
00415             dahdip->fmts.dstfmt = AST_FORMAT_ULAW;
00416          }
00417          tried_once = 1;
00418          goto retry;
00419       }
00420       ast_log(LOG_ERROR, "Unable to attach to transcoder: %s\n", strerror(errno));
00421       close(fd);
00422 
00423       return -1;
00424    }
00425 
00426    flags = fcntl(fd, F_GETFL);
00427    if (flags > - 1) {
00428       if (fcntl(fd, F_SETFL, flags | O_NONBLOCK))
00429          ast_log(LOG_WARNING, "Could not set non-block mode!\n");
00430    }
00431 
00432    dahdip->fd = fd;
00433 
00434    dahdip->required_samples = ((dahdip->fmts.dstfmt|dahdip->fmts.srcfmt)&AST_FORMAT_G723_1) ? G723_SAMPLES : G729_SAMPLES;
00435 
00436    switch (dahdip->fmts.dstfmt) {
00437    case AST_FORMAT_G729A:
00438       ast_atomic_fetchadd_int(&channels.encoders, +1);
00439       break;
00440    case AST_FORMAT_G723_1:
00441       ast_atomic_fetchadd_int(&channels.encoders, +1);
00442       break;
00443    default:
00444       ast_atomic_fetchadd_int(&channels.decoders, +1);
00445       break;
00446    }
00447 
00448    return 0;
00449 }
00450 
00451 static int dahdi_new(struct ast_trans_pvt *pvt)
00452 {
00453    return dahdi_translate(pvt, pvt->t->dstfmt, pvt->t->srcfmt);
00454 }
00455 
00456 static struct ast_frame *fakesrc_sample(void)
00457 {
00458    /* Don't bother really trying to test hardware ones. */
00459    static struct ast_frame f = {
00460       .frametype = AST_FRAME_VOICE,
00461       .samples = 160,
00462       .src = __PRETTY_FUNCTION__
00463    };
00464 
00465    return &f;
00466 }
00467 
00468 static int is_encoder(struct translator *zt)
00469 {
00470    if (zt->t.srcfmt&(AST_FORMAT_ULAW|AST_FORMAT_ALAW|AST_FORMAT_SLINEAR)) {
00471       return 1;
00472    } else {
00473       return 0;
00474    }
00475 }
00476 
00477 static int register_translator(int dst, int src)
00478 {
00479    struct translator *zt;
00480    int res;
00481 
00482    if (!(zt = ast_calloc(1, sizeof(*zt)))) {
00483       return -1;
00484    }
00485 
00486    snprintf((char *) (zt->t.name), sizeof(zt->t.name), "zap%sto%s",
00487        ast_getformatname((1 << src)), ast_getformatname((1 << dst)));
00488    zt->t.srcfmt = (1 << src);
00489    zt->t.dstfmt = (1 << dst);
00490    zt->t.buf_size = BUFFER_SIZE;
00491    if (is_encoder(zt)) {
00492       zt->t.framein = dahdi_encoder_framein;
00493       zt->t.frameout = dahdi_encoder_frameout;
00494    } else {
00495       zt->t.framein = dahdi_decoder_framein;
00496       zt->t.frameout = dahdi_decoder_frameout;
00497    }
00498    zt->t.destroy = dahdi_destroy;
00499    zt->t.buffer_samples = 0;
00500    zt->t.newpvt = dahdi_new;
00501    zt->t.sample = fakesrc_sample;
00502    zt->t.native_plc = 0;
00503 
00504    zt->t.desc_size = sizeof(struct codec_dahdi_pvt);
00505    if ((res = ast_register_translator(&zt->t))) {
00506       ast_free(zt);
00507       return -1;
00508    }
00509 
00510    AST_LIST_LOCK(&translators);
00511    AST_LIST_INSERT_HEAD(&translators, zt, entry);
00512    AST_LIST_UNLOCK(&translators);
00513 
00514    global_format_map.map[dst][src] = 1;
00515 
00516    return res;
00517 }
00518 
00519 static void drop_translator(int dst, int src)
00520 {
00521    struct translator *cur;
00522 
00523    AST_LIST_LOCK(&translators);
00524    AST_LIST_TRAVERSE_SAFE_BEGIN(&translators, cur, entry) {
00525       if (cur->t.srcfmt != src)
00526          continue;
00527 
00528       if (cur->t.dstfmt != dst)
00529          continue;
00530 
00531       AST_LIST_REMOVE_CURRENT(entry);
00532       ast_unregister_translator(&cur->t);
00533       ast_free(cur);
00534       global_format_map.map[dst][src] = 0;
00535       break;
00536    }
00537    AST_LIST_TRAVERSE_SAFE_END;
00538    AST_LIST_UNLOCK(&translators);
00539 }
00540 
00541 static void unregister_translators(void)
00542 {
00543    struct translator *cur;
00544 
00545    AST_LIST_LOCK(&translators);
00546    while ((cur = AST_LIST_REMOVE_HEAD(&translators, entry))) {
00547       ast_unregister_translator(&cur->t);
00548       ast_free(cur);
00549    }
00550    AST_LIST_UNLOCK(&translators);
00551 }
00552 
00553 static void build_translators(struct format_map *map, unsigned int dstfmts, unsigned int srcfmts)
00554 {
00555    unsigned int src, dst;
00556 
00557    for (src = 0; src < 32; src++) {
00558       for (dst = 0; dst < 32; dst++) {
00559          if (!(srcfmts & (1 << src)))
00560             continue;
00561 
00562          if (!(dstfmts & (1 << dst)))
00563             continue;
00564 
00565          if (global_format_map.map[dst][src])
00566             continue;
00567 
00568          if (!register_translator(dst, src))
00569             map->map[dst][src] = 1;
00570       }
00571    }
00572 }
00573 
00574 static int find_transcoders(void)
00575 {
00576    struct dahdi_transcoder_info info = { 0, };
00577    struct format_map map = { { { 0 } } };
00578    int fd, res;
00579    unsigned int x, y;
00580 
00581    if ((fd = open("/dev/dahdi/transcode", O_RDWR)) < 0) {
00582       ast_log(LOG_ERROR, "Failed to open /dev/dahdi/transcode: %s\n", strerror(errno));
00583       return 0;
00584    }
00585 
00586    for (info.tcnum = 0; !(res = ioctl(fd, DAHDI_TC_GETINFO, &info)); info.tcnum++) {
00587       if (option_verbose > 1)
00588          ast_verbose(VERBOSE_PREFIX_2 "Found transcoder '%s'.\n", info.name);
00589 
00590       /* Complex codecs need to support signed linear.  If the
00591        * hardware transcoder does not natively support signed linear
00592        * format, we will emulate it in software directly in this
00593        * module. Also, do not allow direct ulaw/alaw to complex
00594        * codec translation, since that will prevent the generic PLC
00595        * functions from working. */
00596       if (info.dstfmts & (AST_FORMAT_ULAW | AST_FORMAT_ALAW)) {
00597          info.dstfmts |= AST_FORMAT_SLINEAR;
00598          info.dstfmts &= ~(AST_FORMAT_ULAW | AST_FORMAT_ALAW);
00599       }
00600       if (info.srcfmts & (AST_FORMAT_ULAW | AST_FORMAT_ALAW)) {
00601          info.srcfmts |= AST_FORMAT_SLINEAR;
00602          info.srcfmts &= ~(AST_FORMAT_ULAW | AST_FORMAT_ALAW);
00603       }
00604 
00605       build_translators(&map, info.dstfmts, info.srcfmts);
00606       ast_atomic_fetchadd_int(&channels.total, info.numchannels / 2);
00607 
00608    }
00609 
00610    close(fd);
00611 
00612    if (!info.tcnum && (option_verbose > 1))
00613       ast_verbose(VERBOSE_PREFIX_2 "No hardware transcoders found.\n");
00614 
00615    for (x = 0; x < 32; x++) {
00616       for (y = 0; y < 32; y++) {
00617          if (!map.map[x][y] && global_format_map.map[x][y])
00618             drop_translator(x, y);
00619       }
00620    }
00621 
00622    return 0;
00623 }
00624 
00625 static int reload(void)
00626 {
00627    return AST_MODULE_LOAD_SUCCESS;
00628 }
00629 
00630 static int unload_module(void)
00631 {
00632    ast_cli_unregister_multiple(cli, ARRAY_LEN(cli));
00633    unregister_translators();
00634 
00635    return 0;
00636 }
00637 
00638 static int load_module(void)
00639 {
00640    ast_ulaw_init();
00641    find_transcoders();
00642    ast_cli_register_multiple(cli, ARRAY_LEN(cli));
00643    return AST_MODULE_LOAD_SUCCESS;
00644 }
00645 
00646 AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT, "Generic DAHDI Transcoder Codec Translator",
00647       .load = load_module,
00648       .unload = unload_module,
00649       .reload = reload,
00650           );