Mon May 14 04:42:58 2007

Asterisk developer's documentation


codec_zap.c

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Zaptel native transcoding support
00005  *
00006  * Copyright (C) 1999 - 2006, 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 Zaptel transcoding
00025  *
00026  * \ingroup codecs
00027  */
00028 
00029 /*** MODULEINFO
00030    <depend>zaptel_transcode</depend>
00031    <depend>zaptel</depend>
00032  ***/
00033 
00034 #include "asterisk.h"
00035 
00036 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
00037 
00038 #include <fcntl.h>
00039 #include <stdlib.h>
00040 #include <unistd.h>
00041 #include <netinet/in.h>
00042 #include <string.h>
00043 #include <stdio.h>
00044 #include <sys/ioctl.h>
00045 #include <errno.h>
00046 #include <sys/mman.h>
00047 #include <zaptel/zaptel.h>
00048 
00049 #include "asterisk/lock.h"
00050 #include "asterisk/translate.h"
00051 #include "asterisk/config.h"
00052 #include "asterisk/options.h"
00053 #include "asterisk/module.h"
00054 #include "asterisk/logger.h"
00055 #include "asterisk/channel.h"
00056 #include "asterisk/utils.h"
00057 #include "asterisk/linkedlists.h"
00058 
00059 #define BUFFER_SAMPLES  8000
00060 
00061 static unsigned int global_useplc = 0;
00062 
00063 struct format_map {
00064    unsigned int map[32][32];
00065 };
00066 
00067 static struct format_map global_format_map = { { { 0 } } };
00068 
00069 struct translator {
00070    struct ast_translator t;
00071    AST_LIST_ENTRY(translator) entry;
00072 };
00073 
00074 static AST_LIST_HEAD_STATIC(translators, translator);
00075 
00076 struct pvt {
00077    int fd;
00078    int fake;
00079 #ifdef DEBUG_TRANSCODE
00080    int totalms;
00081    int lasttotalms;
00082 #endif
00083    struct zt_transcode_header *hdr;
00084    struct ast_frame f;
00085 };
00086 
00087 static int zap_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
00088 {
00089    struct pvt *ztp = pvt->pvt;
00090    struct zt_transcode_header *hdr = ztp->hdr;
00091 
00092    if (!f->subclass) {
00093       /* Fake a return frame for calculation purposes */
00094       ztp->fake = 2;
00095       pvt->samples = f->samples;
00096       return 0;
00097    }
00098 
00099    if (!hdr->srclen)
00100       /* Copy at front of buffer */
00101       hdr->srcoffset = 0;
00102 
00103    if (hdr->srclen + f->datalen > sizeof(hdr->srcdata)) {
00104       ast_log(LOG_WARNING, "Out of space for codec translation!\n");
00105       return -1;
00106    }
00107 
00108    if (hdr->srclen + f->datalen + hdr->srcoffset > sizeof(hdr->srcdata)) {
00109       /* Very unlikely */
00110       memmove(hdr->srcdata, hdr->srcdata + hdr->srcoffset, hdr->srclen);
00111       hdr->srcoffset = 0;
00112    }
00113 
00114    memcpy(hdr->srcdata + hdr->srcoffset + hdr->srclen, f->data, f->datalen);
00115    hdr->srclen += f->datalen;
00116    pvt->samples += f->samples;
00117 
00118    return -1;
00119 }
00120 
00121 static struct ast_frame *zap_frameout(struct ast_trans_pvt *pvt)
00122 {
00123    struct pvt *ztp = pvt->pvt;
00124    struct zt_transcode_header *hdr = ztp->hdr;
00125    unsigned int x;
00126 
00127    if (ztp->fake == 2) {
00128       ztp->fake = 1;
00129       ztp->f.frametype = AST_FRAME_VOICE;
00130       ztp->f.subclass = 0;
00131       ztp->f.samples = 160;
00132       ztp->f.data = NULL;
00133       ztp->f.offset = 0;
00134       ztp->f.datalen = 0;
00135       ztp->f.mallocd = 0;
00136       pvt->samples = 0;
00137    } else if (ztp->fake == 1) {
00138       return NULL;
00139    } else {
00140       if (hdr->dstlen) {
00141 #ifdef DEBUG_TRANSCODE
00142          ztp->totalms += hdr->dstsamples;
00143          if ((ztp->totalms - ztp->lasttotalms) > 8000) {
00144             printf("Whee %p, %d (%d to %d)\n", ztp, hdr->dstlen, ztp->lasttotalms, ztp->totalms);
00145             ztp->lasttotalms = ztp->totalms;
00146          }
00147 #endif
00148          ztp->f.frametype = AST_FRAME_VOICE;
00149          ztp->f.subclass = hdr->dstfmt;
00150          ztp->f.samples = hdr->dstsamples;
00151          ztp->f.data = hdr->dstdata + hdr->dstoffset;
00152          ztp->f.offset = hdr->dstoffset;
00153          ztp->f.datalen = hdr->dstlen;
00154          ztp->f.mallocd = 0;
00155          pvt->samples -= ztp->f.samples;
00156          hdr->dstlen = 0;
00157          
00158       } else {
00159          if (hdr->srclen) {
00160             hdr->dstoffset = AST_FRIENDLY_OFFSET;
00161             x = ZT_TCOP_TRANSCODE;
00162             if (ioctl(ztp->fd, ZT_TRANSCODE_OP, &x))
00163                ast_log(LOG_WARNING, "Failed to transcode: %s\n", strerror(errno));
00164          }
00165          return NULL;
00166       }
00167    }
00168 
00169    return &ztp->f;
00170 }
00171 
00172 static void zap_destroy(struct ast_trans_pvt *pvt)
00173 {
00174    struct pvt *ztp = pvt->pvt;
00175 
00176    munmap(ztp->hdr, sizeof(*ztp->hdr));
00177    close(ztp->fd);
00178 }
00179 
00180 static int zap_translate(struct ast_trans_pvt *pvt, int dest, int source)
00181 {
00182    /* Request translation through zap if possible */
00183    int fd;
00184    unsigned int x = ZT_TCOP_ALLOCATE;
00185    struct pvt *ztp = pvt->pvt;
00186    struct zt_transcode_header *hdr;
00187    int flags;
00188    
00189    if ((fd = open("/dev/zap/transcode", O_RDWR)) < 0)
00190       return -1;
00191    flags = fcntl(fd, F_GETFL);
00192    if (flags > - 1) {
00193       if (fcntl(fd, F_SETFL, flags | O_NONBLOCK))
00194          ast_log(LOG_WARNING, "Could not set non-block mode!\n");
00195    }
00196    
00197 
00198    if ((hdr = mmap(NULL, sizeof(*hdr), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0)) == MAP_FAILED) {
00199       ast_log(LOG_ERROR, "Memory Map failed for transcoding (%s)\n", strerror(errno));
00200       close(fd);
00201 
00202       return -1;
00203    }
00204 
00205    if (hdr->magic != ZT_TRANSCODE_MAGIC) {
00206       ast_log(LOG_ERROR, "Transcoder header (%08x) wasn't magic.  Abandoning\n", hdr->magic);
00207       munmap(hdr, sizeof(*hdr));
00208       close(fd);
00209 
00210       return -1;
00211    }
00212    
00213    hdr->srcfmt = (1 << source);
00214    hdr->dstfmt = (1 << dest);
00215    if (ioctl(fd, ZT_TRANSCODE_OP, &x)) {
00216       ast_log(LOG_ERROR, "Unable to attach transcoder: %s\n", strerror(errno));
00217       munmap(hdr, sizeof(*hdr));
00218       close(fd);
00219 
00220       return -1;
00221    }
00222 
00223    ztp = pvt->pvt;
00224    ztp->fd = fd;
00225    ztp->hdr = hdr;
00226 
00227    return 0;
00228 }
00229 
00230 static int zap_new(struct ast_trans_pvt *pvt)
00231 {
00232    return zap_translate(pvt, pvt->t->dstfmt, pvt->t->srcfmt);
00233 }
00234 
00235 static struct ast_frame *fakesrc_sample(void)
00236 {
00237    /* Don't bother really trying to test hardware ones. */
00238    static struct ast_frame f = {
00239       .frametype = AST_FRAME_VOICE,
00240       .samples = 160,
00241       .src = __PRETTY_FUNCTION__
00242    };
00243 
00244    return &f;
00245 }
00246 
00247 static int register_translator(int dst, int src)
00248 {
00249    struct translator *zt;
00250    int res;
00251 
00252    if (!(zt = ast_calloc(1, sizeof(*zt))))
00253       return -1;
00254 
00255    snprintf((char *) (zt->t.name), sizeof(zt->t.name), "zap%sto%s", 
00256        ast_getformatname((1 << src)), ast_getformatname((1 << dst)));
00257    zt->t.srcfmt = (1 << src);
00258    zt->t.dstfmt = (1 << dst);
00259    zt->t.newpvt = zap_new;
00260    zt->t.framein = zap_framein;
00261    zt->t.frameout = zap_frameout;
00262    zt->t.destroy = zap_destroy;
00263    zt->t.sample = fakesrc_sample;
00264    zt->t.useplc = global_useplc;
00265    zt->t.buf_size = BUFFER_SAMPLES * 2;
00266    zt->t.desc_size = sizeof(struct pvt);
00267    if ((res = ast_register_translator(&zt->t))) {
00268       free(zt);
00269       return -1;
00270    }
00271 
00272    AST_LIST_LOCK(&translators);
00273    AST_LIST_INSERT_HEAD(&translators, zt, entry);
00274    AST_LIST_UNLOCK(&translators);
00275 
00276    global_format_map.map[dst][src] = 1;
00277 
00278    return res;
00279 }
00280 
00281 static void drop_translator(int dst, int src)
00282 {
00283    struct translator *cur;
00284 
00285    AST_LIST_LOCK(&translators);
00286    AST_LIST_TRAVERSE_SAFE_BEGIN(&translators, cur, entry) {
00287       if (cur->t.srcfmt != src)
00288          continue;
00289 
00290       if (cur->t.dstfmt != dst)
00291          continue;
00292 
00293       AST_LIST_REMOVE_CURRENT(&translators, entry);
00294       ast_unregister_translator(&cur->t);
00295       free(cur);
00296       global_format_map.map[dst][src] = 0;
00297       break;
00298    }
00299    AST_LIST_TRAVERSE_SAFE_END;
00300    AST_LIST_UNLOCK(&translators);
00301 }
00302 
00303 static void unregister_translators(void)
00304 {
00305    struct translator *cur;
00306 
00307    AST_LIST_LOCK(&translators);
00308    while ((cur = AST_LIST_REMOVE_HEAD(&translators, entry))) {
00309       ast_unregister_translator(&cur->t);
00310       free(cur);
00311    }
00312    AST_LIST_UNLOCK(&translators);
00313 }
00314 
00315 static void parse_config(void)
00316 {
00317    struct ast_variable *var;
00318    struct ast_config *cfg = ast_config_load("codecs.conf");
00319 
00320    if (!cfg)
00321       return;
00322 
00323    for (var = ast_variable_browse(cfg, "plc"); var; var = var->next) {
00324           if (!strcasecmp(var->name, "genericplc")) {
00325              global_useplc = ast_true(var->value);
00326              if (option_verbose > 2)
00327                 ast_verbose(VERBOSE_PREFIX_3 "codec_zap: %susing generic PLC\n",
00328                   global_useplc ? "" : "not ");
00329           }
00330    }
00331 
00332    ast_config_destroy(cfg);
00333 }
00334 
00335 static void build_translators(struct format_map *map, unsigned int dstfmts, unsigned int srcfmts)
00336 {
00337    unsigned int src, dst;
00338 
00339    for (src = 0; src < 32; src++) {
00340       for (dst = 0; dst < 32; dst++) {
00341          if (!(srcfmts & (1 << src)))
00342             continue;
00343 
00344          if (!(dstfmts & (1 << dst)))
00345             continue;
00346 
00347          if (global_format_map.map[dst][src])
00348             continue;
00349 
00350          if (!register_translator(dst, src))
00351             map->map[dst][src] = 1;
00352       }
00353    }
00354 }
00355 
00356 static int find_transcoders(void)
00357 {
00358    struct zt_transcode_info info = { 0, };
00359    struct format_map map = { { { 0 } } };
00360    int fd, res;
00361    unsigned int x, y;
00362 
00363    info.op = ZT_TCOP_GETINFO;
00364    if ((fd = open("/dev/zap/transcode", O_RDWR)) < 0) {
00365       ast_log(LOG_DEBUG, "No Zaptel transcoder support!\n");
00366       return 0;
00367    }
00368    for (info.tcnum = 0; !(res = ioctl(fd, ZT_TRANSCODE_OP, &info)); info.tcnum++) {
00369       if (option_verbose > 1)
00370          ast_verbose(VERBOSE_PREFIX_2 "Found transcoder '%s'.\n", info.name);
00371       build_translators(&map, info.dstfmts, info.srcfmts);
00372    }
00373    close(fd);
00374 
00375    if (!info.tcnum && (option_verbose > 1))
00376       ast_verbose(VERBOSE_PREFIX_2 "No hardware transcoders found.\n");
00377 
00378    for (x = 0; x < 32; x++) {
00379       for (y = 0; y < 32; y++) {
00380          if (!map.map[x][y] && global_format_map.map[x][y])
00381             drop_translator(x, y);
00382       }
00383    }
00384 
00385    return 0;
00386 }
00387 
00388 static int reload(void)
00389 {
00390    struct translator *cur;
00391 
00392    parse_config();
00393 
00394    AST_LIST_LOCK(&translators);
00395    AST_LIST_TRAVERSE(&translators, cur, entry)
00396       cur->t.useplc = global_useplc;
00397    AST_LIST_UNLOCK(&translators);
00398 
00399    return 0;
00400 }
00401 
00402 static int unload_module(void)
00403 {
00404    unregister_translators();
00405 
00406    return 0;
00407 }
00408 
00409 static int load_module(void)
00410 {
00411    parse_config();
00412    find_transcoders();
00413 
00414    return 0;
00415 }
00416 
00417 AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT, "Generic Zaptel Transcoder Codec Translator",
00418       .load = load_module,
00419       .unload = unload_module,
00420       .reload = reload,
00421           );

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