Mon Jul 14 17:25:02 2008

Asterisk developer's documentation


translate.c

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00001 /*
00002  * Asterisk -- An open source telephony toolkit.
00003  *
00004  * Copyright (C) 1999 - 2006, Digium, Inc.
00005  *
00006  * Mark Spencer <markster@digium.com>
00007  *
00008  * See http://www.asterisk.org for more information about
00009  * the Asterisk project. Please do not directly contact
00010  * any of the maintainers of this project for assistance;
00011  * the project provides a web site, mailing lists and IRC
00012  * channels for your use.
00013  *
00014  * This program is free software, distributed under the terms of
00015  * the GNU General Public License Version 2. See the LICENSE file
00016  * at the top of the source tree.
00017  */
00018 
00019 /*! \file
00020  *
00021  * \brief Translate via the use of pseudo channels
00022  *
00023  * \author Mark Spencer <markster@digium.com> 
00024  */
00025 
00026 #include "asterisk.h"
00027 
00028 ASTERISK_FILE_VERSION(__FILE__, "$Revision: 105932 $")
00029 
00030 #include <sys/types.h>
00031 #include <sys/socket.h>
00032 #include <sys/time.h>
00033 #include <unistd.h>
00034 #include <stdlib.h>
00035 #include <string.h>
00036 #include <stdio.h>
00037 
00038 #include "asterisk/lock.h"
00039 #include "asterisk/channel.h"
00040 #include "asterisk/logger.h"
00041 #include "asterisk/translate.h"
00042 #include "asterisk/module.h"
00043 #include "asterisk/options.h"
00044 #include "asterisk/frame.h"
00045 #include "asterisk/sched.h"
00046 #include "asterisk/cli.h"
00047 #include "asterisk/term.h"
00048 
00049 #define MAX_RECALC 200 /* max sample recalc */
00050 
00051 /*! \brief the list of translators */
00052 static AST_LIST_HEAD_STATIC(translators, ast_translator);
00053 
00054 struct translator_path {
00055    struct ast_translator *step;  /*!< Next step translator */
00056    unsigned int cost;      /*!< Complete cost to destination */
00057    unsigned int multistep;    /*!< Multiple conversions required for this translation */
00058 };
00059 
00060 /*! \brief a matrix that, for any pair of supported formats,
00061  * indicates the total cost of translation and the first step.
00062  * The full path can be reconstricted iterating on the matrix
00063  * until step->dstfmt == desired_format.
00064  *
00065  * Array indexes are 'src' and 'dest', in that order.
00066  *
00067  * Note: the lock in the 'translators' list is also used to protect
00068  * this structure.
00069  */
00070 static struct translator_path tr_matrix[MAX_FORMAT][MAX_FORMAT];
00071 
00072 /*! \todo
00073  * TODO: sample frames for each supported input format.
00074  * We build this on the fly, by taking an SLIN frame and using
00075  * the existing converter to play with it.
00076  */
00077 
00078 /*! \brief returns the index of the lowest bit set */
00079 static force_inline int powerof(unsigned int d)
00080 {
00081    int x = ffs(d);
00082 
00083    if (x)
00084       return x - 1;
00085 
00086    ast_log(LOG_WARNING, "No bits set? %d\n", d);
00087 
00088    return -1;
00089 }
00090 
00091 /*
00092  * wrappers around the translator routines.
00093  */
00094 
00095 /*!
00096  * \brief Allocate the descriptor, required outbuf space,
00097  * and possibly also plc and desc.
00098  */
00099 static void *newpvt(struct ast_translator *t)
00100 {
00101    struct ast_trans_pvt *pvt;
00102    int len;
00103    int useplc = t->plc_samples > 0 && t->useplc;   /* cache, because it can change on the fly */
00104    char *ofs;
00105 
00106    /*
00107     * compute the required size adding private descriptor,
00108     * plc, buffer, AST_FRIENDLY_OFFSET.
00109     */
00110    len = sizeof(*pvt) + t->desc_size;
00111    if (useplc)
00112       len += sizeof(plc_state_t);
00113    if (t->buf_size)
00114       len += AST_FRIENDLY_OFFSET + t->buf_size;
00115    pvt = ast_calloc(1, len);
00116    if (!pvt)
00117       return NULL;
00118    pvt->t = t;
00119    ofs = (char *)(pvt + 1);   /* pointer to data space */
00120    if (t->desc_size) {     /* first comes the descriptor */
00121       pvt->pvt = ofs;
00122       ofs += t->desc_size;
00123    }
00124    if (useplc) {        /* then plc state */
00125       pvt->plc = (plc_state_t *)ofs;
00126       ofs += sizeof(plc_state_t);
00127    }
00128    if (t->buf_size)     /* finally buffer and header */
00129       pvt->outbuf = ofs + AST_FRIENDLY_OFFSET;
00130    /* call local init routine, if present */
00131    if (t->newpvt && t->newpvt(pvt)) {
00132       free(pvt);
00133       return NULL;
00134    }
00135    ast_module_ref(t->module);
00136    return pvt;
00137 }
00138 
00139 static void destroy(struct ast_trans_pvt *pvt)
00140 {
00141    struct ast_translator *t = pvt->t;
00142 
00143    if (ast_test_flag(&pvt->f, AST_FRFLAG_FROM_TRANSLATOR)) {
00144       /* If this flag is still set, that means that the translation path has
00145        * been torn down, while we still have a frame out there being used.
00146        * When ast_frfree() gets called on that frame, this ast_trans_pvt
00147        * will get destroyed, too. */
00148 
00149       /* Set the magic hint that this has been requested to be destroyed. */
00150       pvt->datalen = -1;
00151 
00152       return;
00153    }
00154 
00155    if (t->destroy)
00156       t->destroy(pvt);
00157    free(pvt);
00158    ast_module_unref(t->module);
00159 }
00160 
00161 /*! \brief framein wrapper, deals with plc and bound checks.  */
00162 static int framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
00163 {
00164    int16_t *dst = (int16_t *)pvt->outbuf;
00165    int ret;
00166    int samples = pvt->samples;   /* initial value */
00167    
00168    /* Copy the last in jb timing info to the pvt */
00169    ast_copy_flags(&pvt->f, f, AST_FRFLAG_HAS_TIMING_INFO);
00170    pvt->f.ts = f->ts;
00171    pvt->f.len = f->len;
00172    pvt->f.seqno = f->seqno;
00173 
00174    if (f->samples == 0) {
00175       ast_log(LOG_WARNING, "no samples for %s\n", pvt->t->name);
00176    }
00177    if (pvt->t->buffer_samples) { /* do not pass empty frames to callback */
00178       if (f->datalen == 0) { /* perform PLC with nominal framesize of 20ms/160 samples */
00179          if (pvt->plc) {
00180             int l = pvt->t->plc_samples;
00181             if (pvt->samples + l > pvt->t->buffer_samples) {
00182                ast_log(LOG_WARNING, "Out of buffer space\n");
00183                return -1;
00184             }
00185             l = plc_fillin(pvt->plc, dst + pvt->samples, l);
00186             pvt->samples += l;
00187             pvt->datalen = pvt->samples * 2; /* SLIN has 2bytes for 1sample */
00188          }
00189          /* We don't want generic PLC. If the codec has native PLC, then do that */
00190          if (!pvt->t->native_plc)
00191             return 0;
00192       }
00193       if (pvt->samples + f->samples > pvt->t->buffer_samples) {
00194          ast_log(LOG_WARNING, "Out of buffer space\n");
00195          return -1;
00196       }
00197    }
00198    /* we require a framein routine, wouldn't know how to do
00199     * it otherwise.
00200     */
00201    ret = pvt->t->framein(pvt, f);
00202    /* possibly store data for plc */
00203    if (!ret && pvt->plc) {
00204       int l = pvt->t->plc_samples;
00205       if (pvt->samples < l)
00206          l = pvt->samples;
00207       plc_rx(pvt->plc, dst + pvt->samples - l, l);
00208    }
00209    /* diagnostic ... */
00210    if (pvt->samples == samples)
00211       ast_log(LOG_WARNING, "%s did not update samples %d\n",
00212          pvt->t->name, pvt->samples);
00213         return ret;
00214 }
00215 
00216 /*! \brief generic frameout routine.
00217  * If samples and datalen are 0, take whatever is in pvt
00218  * and reset them, otherwise take the values in the caller and
00219  * leave alone the pvt values.
00220  */
00221 struct ast_frame *ast_trans_frameout(struct ast_trans_pvt *pvt,
00222    int datalen, int samples)
00223 {
00224    struct ast_frame *f = &pvt->f;
00225 
00226         if (samples)
00227       f->samples = samples;
00228    else {
00229       if (pvt->samples == 0)
00230          return NULL;
00231       f->samples = pvt->samples;
00232       pvt->samples = 0;
00233    }
00234    if (datalen)
00235       f->datalen = datalen;
00236    else {
00237       f->datalen = pvt->datalen;
00238       pvt->datalen = 0;
00239    }
00240 
00241    f->frametype = AST_FRAME_VOICE;
00242    f->subclass = 1 << (pvt->t->dstfmt);
00243    f->mallocd = 0;
00244    f->offset = AST_FRIENDLY_OFFSET;
00245    f->src = pvt->t->name;
00246    f->data = pvt->outbuf;
00247 
00248    ast_set_flag(f, AST_FRFLAG_FROM_TRANSLATOR);
00249 
00250    return f;
00251 }
00252 
00253 static struct ast_frame *default_frameout(struct ast_trans_pvt *pvt)
00254 {
00255    return ast_trans_frameout(pvt, 0, 0);
00256 }
00257 
00258 /* end of callback wrappers and helpers */
00259 
00260 void ast_translator_free_path(struct ast_trans_pvt *p)
00261 {
00262    struct ast_trans_pvt *pn = p;
00263    while ( (p = pn) ) {
00264       pn = p->next;
00265       destroy(p);
00266    }
00267 }
00268 
00269 /*! \brief Build a chain of translators based upon the given source and dest formats */
00270 struct ast_trans_pvt *ast_translator_build_path(int dest, int source)
00271 {
00272    struct ast_trans_pvt *head = NULL, *tail = NULL;
00273    
00274    source = powerof(source);
00275    dest = powerof(dest);
00276    
00277    AST_LIST_LOCK(&translators);
00278 
00279    while (source != dest) {
00280       struct ast_trans_pvt *cur;
00281       struct ast_translator *t = tr_matrix[source][dest].step;
00282       if (!t) {
00283          ast_log(LOG_WARNING, "No translator path from %s to %s\n", 
00284             ast_getformatname(source), ast_getformatname(dest));
00285          AST_LIST_UNLOCK(&translators);
00286          return NULL;
00287       }
00288       if (!(cur = newpvt(t))) {
00289          ast_log(LOG_WARNING, "Failed to build translator step from %d to %d\n", source, dest);
00290          if (head)
00291             ast_translator_free_path(head);  
00292          AST_LIST_UNLOCK(&translators);
00293          return NULL;
00294       }
00295       if (!head)
00296          head = cur;
00297       else
00298          tail->next = cur;
00299       tail = cur;
00300       cur->nextin = cur->nextout = ast_tv(0, 0);
00301       /* Keep going if this isn't the final destination */
00302       source = cur->t->dstfmt;
00303    }
00304 
00305    AST_LIST_UNLOCK(&translators);
00306    return head;
00307 }
00308 
00309 /*! \brief do the actual translation */
00310 struct ast_frame *ast_translate(struct ast_trans_pvt *path, struct ast_frame *f, int consume)
00311 {
00312    struct ast_trans_pvt *p = path;
00313    struct ast_frame *out = f;
00314    struct timeval delivery;
00315    int has_timing_info;
00316    long ts;
00317    long len;
00318    int seqno;
00319 
00320    has_timing_info = ast_test_flag(f, AST_FRFLAG_HAS_TIMING_INFO);
00321    ts = f->ts;
00322    len = f->len;
00323    seqno = f->seqno;
00324 
00325    /* XXX hmmm... check this below */
00326    if (!ast_tvzero(f->delivery)) {
00327       if (!ast_tvzero(path->nextin)) {
00328          /* Make sure this is in line with what we were expecting */
00329          if (!ast_tveq(path->nextin, f->delivery)) {
00330             /* The time has changed between what we expected and this
00331                most recent time on the new packet.  If we have a
00332                valid prediction adjust our output time appropriately */
00333             if (!ast_tvzero(path->nextout)) {
00334                path->nextout = ast_tvadd(path->nextout,
00335                           ast_tvsub(f->delivery, path->nextin));
00336             }
00337             path->nextin = f->delivery;
00338          }
00339       } else {
00340          /* This is our first pass.  Make sure the timing looks good */
00341          path->nextin = f->delivery;
00342          path->nextout = f->delivery;
00343       }
00344       /* Predict next incoming sample */
00345       path->nextin = ast_tvadd(path->nextin, ast_samp2tv(f->samples, ast_format_rate(f->subclass)));
00346    }
00347    delivery = f->delivery;
00348    for ( ; out && p ; p = p->next) {
00349       framein(p, out);
00350       if (out != f)
00351          ast_frfree(out);
00352       out = p->t->frameout(p);
00353    }
00354    if (consume)
00355       ast_frfree(f);
00356    if (out == NULL)
00357       return NULL;
00358    /* we have a frame, play with times */
00359    if (!ast_tvzero(delivery)) {
00360       /* Regenerate prediction after a discontinuity */
00361       if (ast_tvzero(path->nextout))
00362          path->nextout = ast_tvnow();
00363 
00364       /* Use next predicted outgoing timestamp */
00365       out->delivery = path->nextout;
00366       
00367       /* Predict next outgoing timestamp from samples in this
00368          frame. */
00369       path->nextout = ast_tvadd(path->nextout, ast_samp2tv(out->samples, ast_format_rate(out->subclass)));
00370    } else {
00371       out->delivery = ast_tv(0, 0);
00372       ast_set2_flag(out, has_timing_info, AST_FRFLAG_HAS_TIMING_INFO);
00373       if (has_timing_info) {
00374          out->ts = ts;
00375          out->len = len;
00376          out->seqno = seqno;
00377       }
00378    }
00379    /* Invalidate prediction if we're entering a silence period */
00380    if (out->frametype == AST_FRAME_CNG)
00381       path->nextout = ast_tv(0, 0);
00382    return out;
00383 }
00384 
00385 /*! \brief compute the cost of a single translation step */
00386 static void calc_cost(struct ast_translator *t, int seconds)
00387 {
00388    int num_samples = 0;
00389    struct ast_trans_pvt *pvt;
00390    struct timeval start;
00391    int cost;
00392    int out_rate = ast_format_rate(t->dstfmt);
00393 
00394    if (!seconds)
00395       seconds = 1;
00396    
00397    /* If they don't make samples, give them a terrible score */
00398    if (!t->sample) {
00399       ast_log(LOG_WARNING, "Translator '%s' does not produce sample frames.\n", t->name);
00400       t->cost = 99999;
00401       return;
00402    }
00403 
00404    pvt = newpvt(t);
00405    if (!pvt) {
00406       ast_log(LOG_WARNING, "Translator '%s' appears to be broken and will probably fail.\n", t->name);
00407       t->cost = 99999;
00408       return;
00409    }
00410 
00411    start = ast_tvnow();
00412 
00413    /* Call the encoder until we've processed the required number of samples */
00414    while (num_samples < seconds * out_rate) {
00415       struct ast_frame *f = t->sample();
00416       if (!f) {
00417          ast_log(LOG_WARNING, "Translator '%s' failed to produce a sample frame.\n", t->name);
00418          destroy(pvt);
00419          t->cost = 99999;
00420          return;
00421       }
00422       framein(pvt, f);
00423       ast_frfree(f);
00424       while ((f = t->frameout(pvt))) {
00425          num_samples += f->samples;
00426          ast_frfree(f);
00427       }
00428    }
00429 
00430    cost = ast_tvdiff_ms(ast_tvnow(), start);
00431 
00432    destroy(pvt);
00433 
00434    t->cost = cost / seconds;
00435 
00436    if (!t->cost)
00437       t->cost = 1;
00438 }
00439 
00440 /*!
00441  * \brief rebuild a translation matrix.
00442  * \note This function expects the list of translators to be locked
00443 */
00444 static void rebuild_matrix(int samples)
00445 {
00446    struct ast_translator *t;
00447    int x;      /* source format index */
00448    int y;      /* intermediate format index */
00449    int z;      /* destination format index */
00450 
00451    if (option_debug)
00452       ast_log(LOG_DEBUG, "Resetting translation matrix\n");
00453 
00454    bzero(tr_matrix, sizeof(tr_matrix));
00455 
00456    /* first, compute all direct costs */
00457    AST_LIST_TRAVERSE(&translators, t, list) {
00458       if (!t->active)
00459          continue;
00460 
00461       x = t->srcfmt;
00462       z = t->dstfmt;
00463 
00464       if (samples)
00465          calc_cost(t, samples);
00466      
00467       if (!tr_matrix[x][z].step || t->cost < tr_matrix[x][z].cost) {
00468          tr_matrix[x][z].step = t;
00469          tr_matrix[x][z].cost = t->cost;
00470       }
00471    }
00472 
00473    /*
00474     * For each triple x, y, z of distinct formats, check if there is
00475     * a path from x to z through y which is cheaper than what is
00476     * currently known, and in case, update the matrix.
00477     * Repeat until the matrix is stable.
00478     */
00479    for (;;) {
00480       int changed = 0;
00481       for (x = 0; x < MAX_FORMAT; x++) {      /* source format */
00482          for (y=0; y < MAX_FORMAT; y++) {    /* intermediate format */
00483             if (x == y)                     /* skip ourselves */
00484                continue;
00485 
00486             for (z=0; z<MAX_FORMAT; z++) {  /* dst format */
00487                int newcost;
00488 
00489                if (z == x || z == y)       /* skip null conversions */
00490                   continue;
00491                if (!tr_matrix[x][y].step)  /* no path from x to y */
00492                   continue;
00493                if (!tr_matrix[y][z].step)  /* no path from y to z */
00494                   continue;
00495                newcost = tr_matrix[x][y].cost + tr_matrix[y][z].cost;
00496                if (tr_matrix[x][z].step && newcost >= tr_matrix[x][z].cost)
00497                   continue;               /* x->y->z is more expensive than
00498                                            * the existing path */
00499                /* ok, we can get from x to z via y with a cost that
00500                   is the sum of the transition from x to y and
00501                   from y to z */
00502                    
00503                tr_matrix[x][z].step = tr_matrix[x][y].step;
00504                tr_matrix[x][z].cost = newcost;
00505                tr_matrix[x][z].multistep = 1;
00506                if (option_debug)
00507                   ast_log(LOG_DEBUG, "Discovered %d cost path from %s to %s, via %d\n", tr_matrix[x][z].cost, ast_getformatname(x), ast_getformatname(z), y);
00508                changed++;
00509             }
00510          }
00511       }
00512       if (!changed)
00513          break;
00514    }
00515 }
00516 
00517 /*! \brief CLI "show translation" command handler */
00518 static int show_translation_deprecated(int fd, int argc, char *argv[])
00519 {
00520 #define SHOW_TRANS 13
00521    int x, y, z;
00522    int curlen = 0, longest = 0;
00523 
00524    if (argc > 4) 
00525       return RESULT_SHOWUSAGE;
00526 
00527    AST_LIST_LOCK(&translators);  
00528    
00529    if (argv[2] && !strcasecmp(argv[2], "recalc")) {
00530       z = argv[3] ? atoi(argv[3]) : 1;
00531 
00532       if (z <= 0) {
00533          ast_cli(fd, "         C'mon let's be serious here... defaulting to 1.\n");
00534          z = 1;
00535       }
00536 
00537       if (z > MAX_RECALC) {
00538          ast_cli(fd, "         Maximum limit of recalc exceeded by %d, truncating value to %d\n", z - MAX_RECALC, MAX_RECALC);
00539          z = MAX_RECALC;
00540       }
00541       ast_cli(fd, "         Recalculating Codec Translation (number of sample seconds: %d)\n\n", z);
00542       rebuild_matrix(z);
00543    }
00544 
00545    ast_cli(fd, "         Translation times between formats (in milliseconds) for one second of data\n");
00546    ast_cli(fd, "          Source Format (Rows) Destination Format (Columns)\n\n");
00547    /* Get the length of the longest (usable?) codec name, so we know how wide the left side should be */
00548    for (x = 0; x < SHOW_TRANS; x++) {
00549       curlen = strlen(ast_getformatname(1 << (x)));
00550       if (curlen > longest)
00551          longest = curlen;
00552    }
00553    for (x = -1; x < SHOW_TRANS; x++) {
00554       char line[120];
00555       char *buf = line;
00556       size_t left = sizeof(line) - 1;  /* one initial space */
00557       /* next 2 lines run faster than using ast_build_string() */
00558       *buf++ = ' ';
00559       *buf = '\0';
00560       for (y = -1; y < SHOW_TRANS; y++) {
00561          if (y >= 0)
00562             curlen = strlen(ast_getformatname(1 << (y)));
00563 
00564          if (x >= 0 && y >= 0 && tr_matrix[x][y].step) {
00565             /* XXX 999 is a little hackish
00566                We don't want this number being larger than the shortest (or current) codec
00567                For now, that is "gsm" */
00568             ast_build_string(&buf, &left, "%*d", curlen + 1, tr_matrix[x][y].cost > 999 ? 0 : tr_matrix[x][y].cost);
00569          } else if (x == -1 && y >= 0) {
00570             /* Top row - use a dynamic size */
00571             ast_build_string(&buf, &left, "%*s", curlen + 1, ast_getformatname(1 << (y)) );
00572          } else if (y == -1 && x >= 0) {
00573             /* Left column - use a static size. */
00574             ast_build_string(&buf, &left, "%*s", longest, ast_getformatname(1 << (x)) );
00575          } else if (x >= 0 && y >= 0) {
00576             ast_build_string(&buf, &left, "%*s", curlen + 1, "-");
00577          } else {
00578             ast_build_string(&buf, &left, "%*s", longest, "");
00579          }
00580       }
00581       ast_build_string(&buf, &left, "\n");
00582       ast_cli(fd, line);         
00583    }
00584    AST_LIST_UNLOCK(&translators);
00585    return RESULT_SUCCESS;
00586 }
00587 
00588 static int show_translation(int fd, int argc, char *argv[])
00589 {
00590    int x, y, z;
00591    int curlen = 0, longest = 0;
00592 
00593    if (argc > 5)
00594       return RESULT_SHOWUSAGE;
00595 
00596    AST_LIST_LOCK(&translators);  
00597    
00598    if (argv[3] && !strcasecmp(argv[3], "recalc")) {
00599       z = argv[4] ? atoi(argv[4]) : 1;
00600 
00601       if (z <= 0) {
00602          ast_cli(fd, "         C'mon let's be serious here... defaulting to 1.\n");
00603          z = 1;
00604       }
00605 
00606       if (z > MAX_RECALC) {
00607          ast_cli(fd, "         Maximum limit of recalc exceeded by %d, truncating value to %d\n", z - MAX_RECALC, MAX_RECALC);
00608          z = MAX_RECALC;
00609       }
00610       ast_cli(fd, "         Recalculating Codec Translation (number of sample seconds: %d)\n\n", z);
00611       rebuild_matrix(z);
00612    }
00613 
00614    ast_cli(fd, "         Translation times between formats (in milliseconds) for one second of data\n");
00615    ast_cli(fd, "          Source Format (Rows) Destination Format (Columns)\n\n");
00616    /* Get the length of the longest (usable?) codec name, so we know how wide the left side should be */
00617    for (x = 0; x < SHOW_TRANS; x++) {
00618       curlen = strlen(ast_getformatname(1 << (x)));
00619       if (curlen > longest)
00620          longest = curlen;
00621    }
00622    for (x = -1; x < SHOW_TRANS; x++) {
00623       char line[120];
00624       char *buf = line;
00625       size_t left = sizeof(line) - 1;  /* one initial space */
00626       /* next 2 lines run faster than using ast_build_string() */
00627       *buf++ = ' ';
00628       *buf = '\0';
00629       for (y = -1; y < SHOW_TRANS; y++) {
00630          if (y >= 0)
00631             curlen = strlen(ast_getformatname(1 << (y)));
00632 
00633          if (x >= 0 && y >= 0 && tr_matrix[x][y].step) {
00634             /* XXX 999 is a little hackish
00635                We don't want this number being larger than the shortest (or current) codec
00636                For now, that is "gsm" */
00637             ast_build_string(&buf, &left, "%*d", curlen + 1, tr_matrix[x][y].cost > 999 ? 0 : tr_matrix[x][y].cost);
00638          } else if (x == -1 && y >= 0) {
00639             /* Top row - use a dynamic size */
00640             ast_build_string(&buf, &left, "%*s", curlen + 1, ast_getformatname(1 << (y)) );
00641          } else if (y == -1 && x >= 0) {
00642             /* Left column - use a static size. */
00643             ast_build_string(&buf, &left, "%*s", longest, ast_getformatname(1 << (x)) );
00644          } else if (x >= 0 && y >= 0) {
00645             ast_build_string(&buf, &left, "%*s", curlen + 1, "-");
00646          } else {
00647             ast_build_string(&buf, &left, "%*s", longest, "");
00648          }
00649       }
00650       ast_build_string(&buf, &left, "\n");
00651       ast_cli(fd, line);         
00652    }
00653    AST_LIST_UNLOCK(&translators);
00654    return RESULT_SUCCESS;
00655 }
00656 
00657 static char show_trans_usage[] =
00658 "Usage: core show translation [recalc] [<recalc seconds>]\n"
00659 "       Displays known codec translators and the cost associated\n"
00660 "with each conversion.  If the argument 'recalc' is supplied along\n"
00661 "with optional number of seconds to test a new test will be performed\n"
00662 "as the chart is being displayed.\n";
00663 
00664 static struct ast_cli_entry cli_show_translation_deprecated = {
00665    { "show", "translation", NULL },
00666    show_translation_deprecated, NULL,
00667    NULL };
00668 
00669 static struct ast_cli_entry cli_translate[] = {
00670    { { "core", "show", "translation", NULL },
00671    show_translation, "Display translation matrix",
00672    show_trans_usage, NULL, &cli_show_translation_deprecated },
00673 };
00674 
00675 /*! \brief register codec translator */
00676 int __ast_register_translator(struct ast_translator *t, struct ast_module *mod)
00677 {
00678    static int added_cli = 0;
00679    struct ast_translator *u;
00680 
00681    if (!mod) {
00682       ast_log(LOG_WARNING, "Missing module pointer, you need to supply one\n");
00683       return -1;
00684    }
00685 
00686    if (!t->buf_size) {
00687       ast_log(LOG_WARNING, "empty buf size, you need to supply one\n");
00688       return -1;
00689    }
00690 
00691    t->module = mod;
00692 
00693    t->srcfmt = powerof(t->srcfmt);
00694    t->dstfmt = powerof(t->dstfmt);
00695    t->active = 1;
00696 
00697    if (t->plc_samples) {
00698       if (t->buffer_samples < t->plc_samples) {
00699          ast_log(LOG_WARNING, "plc_samples %d buffer_samples %d\n",
00700             t->plc_samples, t->buffer_samples);
00701          return -1;
00702       }
00703       if (t->dstfmt != powerof(AST_FORMAT_SLINEAR))
00704          ast_log(LOG_WARNING, "plc_samples %d format %x\n",
00705             t->plc_samples, t->dstfmt);
00706    }
00707    if (t->srcfmt >= MAX_FORMAT) {
00708       ast_log(LOG_WARNING, "Source format %s is larger than MAX_FORMAT\n", ast_getformatname(t->srcfmt));
00709       return -1;
00710    }
00711 
00712    if (t->dstfmt >= MAX_FORMAT) {
00713       ast_log(LOG_WARNING, "Destination format %s is larger than MAX_FORMAT\n", ast_getformatname(t->dstfmt));
00714       return -1;
00715    }
00716 
00717    if (t->buf_size) {
00718                /*
00719       * Align buf_size properly, rounding up to the machine-specific
00720       * alignment for pointers.
00721       */
00722       struct _test_align { void *a, *b; } p;
00723       int align = (char *)&p.b - (char *)&p.a;
00724 
00725       t->buf_size = ((t->buf_size + align - 1) / align) * align;
00726    }
00727 
00728    if (t->frameout == NULL)
00729       t->frameout = default_frameout;
00730   
00731    calc_cost(t, 1);
00732 
00733    if (option_verbose > 1) {
00734       char tmp[80];
00735 
00736       ast_verbose(VERBOSE_PREFIX_2 "Registered translator '%s' from format %s to %s, cost %d\n",
00737              term_color(tmp, t->name, COLOR_MAGENTA, COLOR_BLACK, sizeof(tmp)),
00738              ast_getformatname(1 << t->srcfmt), ast_getformatname(1 << t->dstfmt), t->cost);
00739    }
00740 
00741    if (!added_cli) {
00742       ast_cli_register_multiple(cli_translate, sizeof(cli_translate) / sizeof(struct ast_cli_entry));
00743       added_cli++;
00744    }
00745 
00746    AST_LIST_LOCK(&translators);
00747 
00748    /* find any existing translators that provide this same srcfmt/dstfmt,
00749       and put this one in order based on cost */
00750    AST_LIST_TRAVERSE_SAFE_BEGIN(&translators, u, list) {
00751       if ((u->srcfmt == t->srcfmt) &&
00752           (u->dstfmt == t->dstfmt) &&
00753           (u->cost > t->cost)) {
00754          AST_LIST_INSERT_BEFORE_CURRENT(&translators, t, list);
00755          t = NULL;
00756       }
00757    }
00758    AST_LIST_TRAVERSE_SAFE_END;
00759 
00760    /* if no existing translator was found for this format combination,
00761       add it to the beginning of the list */
00762    if (t)
00763       AST_LIST_INSERT_HEAD(&translators, t, list);
00764 
00765    rebuild_matrix(0);
00766 
00767    AST_LIST_UNLOCK(&translators);
00768 
00769    return 0;
00770 }
00771 
00772 /*! \brief unregister codec translator */
00773 int ast_unregister_translator(struct ast_translator *t)
00774 {
00775    char tmp[80];
00776    struct ast_translator *u;
00777    int found = 0;
00778 
00779    AST_LIST_LOCK(&translators);
00780    AST_LIST_TRAVERSE_SAFE_BEGIN(&translators, u, list) {
00781       if (u == t) {
00782          AST_LIST_REMOVE_CURRENT(&translators, list);
00783          if (option_verbose > 1)
00784             ast_verbose(VERBOSE_PREFIX_2 "Unregistered translator '%s' from format %s to %s\n", term_color(tmp, t->name, COLOR_MAGENTA, COLOR_BLACK, sizeof(tmp)), ast_getformatname(1 << t->srcfmt), ast_getformatname(1 << t->dstfmt));
00785          found = 1;
00786          break;
00787       }
00788    }
00789    AST_LIST_TRAVERSE_SAFE_END;
00790 
00791    if (found)
00792       rebuild_matrix(0);
00793 
00794    AST_LIST_UNLOCK(&translators);
00795 
00796    return (u ? 0 : -1);
00797 }
00798 
00799 void ast_translator_activate(struct ast_translator *t)
00800 {
00801    AST_LIST_LOCK(&translators);
00802    t->active = 1;
00803    rebuild_matrix(0);
00804    AST_LIST_UNLOCK(&translators);
00805 }
00806 
00807 void ast_translator_deactivate(struct ast_translator *t)
00808 {
00809    AST_LIST_LOCK(&translators);
00810    t->active = 0;
00811    rebuild_matrix(0);
00812    AST_LIST_UNLOCK(&translators);
00813 }
00814 
00815 /*! \brief Calculate our best translator source format, given costs, and a desired destination */
00816 int ast_translator_best_choice(int *dst, int *srcs)
00817 {
00818    int x,y;
00819    int best = -1;
00820    int bestdst = 0;
00821    int cur, cursrc;
00822    int besttime = INT_MAX;
00823    int beststeps = INT_MAX;
00824    int common = ((*dst) & (*srcs)) & AST_FORMAT_AUDIO_MASK; /* are there common formats ? */
00825 
00826    if (common) { /* yes, pick one and return */
00827       for (cur = 1, y = 0; y <= MAX_AUDIO_FORMAT; cur <<= 1, y++) {
00828          if (cur & common) /* guaranteed to find one */
00829             break;
00830       }
00831       /* We are done, this is a common format to both. */
00832       *srcs = *dst = cur;
00833       return 0;
00834    } else { /* No, we will need to translate */
00835       AST_LIST_LOCK(&translators);
00836       for (cur = 1, y = 0; y <= MAX_AUDIO_FORMAT; cur <<= 1, y++) {
00837          if (! (cur & *dst))
00838             continue;
00839          for (cursrc = 1, x = 0; x <= MAX_AUDIO_FORMAT; cursrc <<= 1, x++) {
00840             if (!(*srcs & cursrc) || !tr_matrix[x][y].step ||
00841                 tr_matrix[x][y].cost >  besttime)
00842                continue;   /* not existing or no better */
00843             if (tr_matrix[x][y].cost < besttime ||
00844                 tr_matrix[x][y].multistep < beststeps) {
00845                /* better than what we have so far */
00846                best = cursrc;
00847                bestdst = cur;
00848                besttime = tr_matrix[x][y].cost;
00849                beststeps = tr_matrix[x][y].multistep;
00850             }
00851          }
00852       }
00853       AST_LIST_UNLOCK(&translators);
00854       if (best > -1) {
00855          *srcs = best;
00856          *dst = bestdst;
00857          best = 0;
00858       }
00859       return best;
00860    }
00861 }
00862 
00863 unsigned int ast_translate_path_steps(unsigned int dest, unsigned int src)
00864 {
00865    unsigned int res = -1;
00866 
00867    /* convert bitwise format numbers into array indices */
00868    src = powerof(src);
00869    dest = powerof(dest);
00870 
00871    AST_LIST_LOCK(&translators);
00872 
00873    if (tr_matrix[src][dest].step)
00874       res = tr_matrix[src][dest].multistep + 1;
00875 
00876    AST_LIST_UNLOCK(&translators);
00877 
00878    return res;
00879 }
00880 
00881 unsigned int ast_translate_available_formats(unsigned int dest, unsigned int src)
00882 {
00883    unsigned int res = dest;
00884    unsigned int x;
00885    unsigned int src_audio = src & AST_FORMAT_AUDIO_MASK;
00886    unsigned int src_video = src & AST_FORMAT_VIDEO_MASK;
00887 
00888    /* if we don't have a source format, we just have to try all
00889       possible destination formats */
00890    if (!src)
00891       return dest;
00892 
00893    /* If we have a source audio format, get its format index */
00894    if (src_audio)
00895       src_audio = powerof(src_audio);
00896 
00897    /* If we have a source video format, get its format index */
00898    if (src_video)
00899       src_video = powerof(src_video);
00900 
00901    AST_LIST_LOCK(&translators);
00902 
00903    /* For a given source audio format, traverse the list of
00904       known audio formats to determine whether there exists
00905       a translation path from the source format to the
00906       destination format. */
00907    for (x = 1; src_audio && x < AST_FORMAT_MAX_AUDIO; x <<= 1) {
00908       /* if this is not a desired format, nothing to do */
00909       if (!dest & x)
00910          continue;
00911 
00912       /* if the source is supplying this format, then
00913          we can leave it in the result */
00914       if (src & x)
00915          continue;
00916 
00917       /* if we don't have a translation path from the src
00918          to this format, remove it from the result */
00919       if (!tr_matrix[src_audio][powerof(x)].step) {
00920          res &= ~x;
00921          continue;
00922       }
00923 
00924       /* now check the opposite direction */
00925       if (!tr_matrix[powerof(x)][src_audio].step)
00926          res &= ~x;
00927    }
00928 
00929    /* For a given source video format, traverse the list of
00930       known video formats to determine whether there exists
00931       a translation path from the source format to the
00932       destination format. */
00933    for (; src_video && x < AST_FORMAT_MAX_VIDEO; x <<= 1) {
00934       /* if this is not a desired format, nothing to do */
00935       if (!dest & x)
00936          continue;
00937 
00938       /* if the source is supplying this format, then
00939          we can leave it in the result */
00940       if (src & x)
00941          continue;
00942 
00943       /* if we don't have a translation path from the src
00944          to this format, remove it from the result */
00945       if (!tr_matrix[src_video][powerof(x)].step) {
00946          res &= ~x;
00947          continue;
00948       }
00949 
00950       /* now check the opposite direction */
00951       if (!tr_matrix[powerof(x)][src_video].step)
00952          res &= ~x;
00953    }
00954 
00955    AST_LIST_UNLOCK(&translators);
00956 
00957    return res;
00958 }
00959 
00960 void ast_translate_frame_freed(struct ast_frame *fr)
00961 {
00962    struct ast_trans_pvt *pvt;
00963 
00964    ast_clear_flag(fr, AST_FRFLAG_FROM_TRANSLATOR);
00965 
00966    pvt = (struct ast_trans_pvt *) (((char *) fr) - offsetof(struct ast_trans_pvt, f));
00967 
00968    if (pvt->datalen != -1)
00969       return;
00970    
00971    destroy(pvt);
00972 }

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