translate.c

   1 /*
   2  * Asterisk -- A telephony toolkit for Linux.
   3  *
   4  * Translate via the use of pseudo channels
   5  *
   6  * Copyright (C) 1999, Mark Spencer
   7  *
   8  * Mark Spencer <markster@linux-support.net>
   9  *
  10  * This program is free software, distributed under the terms of
  11  * the GNU General Public License
  12  */
  13
  14 #include <asterisk/lock.h>
  15 #include <asterisk/channel.h>
  16 #include <asterisk/channel_pvt.h>
  17 #include <asterisk/logger.h>
  18 #include <asterisk/translate.h>
  19 #include <asterisk/options.h>
  20 #include <asterisk/frame.h>
  21 #include <asterisk/sched.h>
  22 #include <asterisk/cli.h>
  23 #include <asterisk/term.h>
  24 #include <sys/socket.h>
  25 #include <sys/time.h>
  26 #include <unistd.h>
  27 #include <stdlib.h>
  28 #include <pthread.h>
  29 #include <string.h>
  30 #include <stdio.h>
  31
  32 /* Uncomment the EXPERIMENTAL_TRANSLATION to enable a more complicated, but probably more
  33    correct way of handling full duplex translation */
  34
  35 /*
  36 #define EXPERIMENTAL_TRANSLATION
  37 */
  38
  39 /* This could all be done more efficiently *IF* we chained packets together
  40    by default, but it would also complicate virtually every application. */
  41
  42 static pthread_mutex_t list_lock = AST_MUTEX_INITIALIZER;
  43 static struct ast_translator *list = NULL;
  44
  45 struct ast_translator_dir {
  46         struct ast_translator *step;    /* Next step translator */
  47         int cost;                                               /* Complete cost to destination */
  48 };
  49
  50 struct ast_frame_delivery {
  51         struct ast_frame *f;
  52         struct ast_channel *chan;
  53         int fd;
  54         struct translator_pvt *owner;
  55         struct ast_frame_delivery *prev;
  56         struct ast_frame_delivery *next;
  57 };
  58
  59 static struct ast_translator_dir tr_matrix[MAX_FORMAT][MAX_FORMAT];
  60
  61 struct ast_trans_pvt {
  62         struct ast_translator *step;
  63         struct ast_translator_pvt *state;
  64         struct ast_trans_pvt *next;
  65 };
  66
  67
  68 static int powerof(int d)
  69 {
  70         int x;
  71         for (x = 0; x < 32; x++)
  72                 if ((1 << x) & d)
  73                         return x;
  74         ast_log(LOG_WARNING, "Powerof %d: No power??\n", d);
  75         return -1;
  76 }
  77
  78 void ast_translator_free_path(struct ast_trans_pvt *p)
  79 {
  80         struct ast_trans_pvt *pl;
  81         while(p) {
  82                 pl = p;
  83                 p = p->next;
  84                 if (pl->state && pl->step->destroy)
  85                         pl->step->destroy(pl->state);
  86                 free(pl);
  87         }
  88 }
  89
  90 struct ast_trans_pvt *ast_translator_build_path(int dest, int source)
  91 {
  92         struct ast_trans_pvt *tmpr = NULL, *tmp = NULL;
  93         /* One of the hardest parts:  Build a set of translators based upon
  94            the given source and destination formats */
  95         source = powerof(source);
  96         dest = powerof(dest);
  97         while(source != dest) {
  98                 if (tr_matrix[source][dest].step) {
  99                         if (tmp) {
 100                                 tmp->next = malloc(sizeof(struct ast_trans_pvt));
 101                                 tmp = tmp->next;
 102                         } else
 103                                 tmp = malloc(sizeof(struct ast_trans_pvt));
 104
 105
 106                         if (tmp) {
 107                                 tmp->next = NULL;
 108                                 tmp->step = tr_matrix[source][dest].step;
 109                                 tmp->state = tmp->step->new();
 110                                 if (!tmp->state) {
 111                                         ast_log(LOG_WARNING, "Failed to build translator step from %d to %d\n", source, dest);
 112                                         free(tmp);
 113                                         tmp = NULL;
 114                                         return NULL;
 115                                 }
 116                                 /* Set the root, if it doesn't exist yet... */
 117                                 if (!tmpr)
 118                                         tmpr = tmp;
 119                                 /* Keep going if this isn't the final destination */
 120                                 source = tmp->step->dstfmt;
 121                         } else {
 122                                 /* XXX This could leak XXX */
 123                                 ast_log(LOG_WARNING, "Out of memory\n");
 124                                 return NULL;
 125                         }
 126                 } else {
 127                         /* We shouldn't have allocated any memory */
 128                         ast_log(LOG_WARNING, "No translator path from %d to %d\n", source, dest);
 129                         return NULL;
 130                 }
 131         }
 132         return tmpr;
 133 }
 134
 135 struct ast_frame *ast_translate(struct ast_trans_pvt *path, struct ast_frame *f, int consume)
 136 {
 137         struct ast_trans_pvt *p;
 138         struct ast_frame *out;
 139         p = path;
 140         /* Feed the first frame into the first translator */
 141         p->step->framein(p->state, f);
 142         if (consume)
 143                 ast_frfree(f);
 144         while(p) {
 145                 out = p->step->frameout(p->state);
 146                 /* If we get nothing out, return NULL */
 147                 if (!out)
 148                         return NULL;
 149                 /* If there is a next state, feed it in there.  If not,
 150                    return this frame  */
 151                 if (p->next)
 152                         p->next->step->framein(p->next->state, out);
 153                 else
 154                         return out;
 155                 p = p->next;
 156         }
 157         ast_log(LOG_WARNING, "I should never get here...\n");
 158         return NULL;
 159 }
 160
 161 static void rebuild_matrix()
 162 {
 163         struct ast_translator *t;
 164         int changed;
 165         int x,y,z;
 166         if (option_debug)
 167                 ast_log(LOG_DEBUG, "Reseting translation matrix\n");
 168         /* Use the list of translators to build a translation matrix */
 169         bzero(tr_matrix, sizeof(tr_matrix));
 170         t = list;
 171         while(t) {
 172                 if (!tr_matrix[t->srcfmt][t->dstfmt].step ||
 173                      tr_matrix[t->srcfmt][t->dstfmt].cost > t->cost) {
 174                         tr_matrix[t->srcfmt][t->dstfmt].step = t;
 175                         tr_matrix[t->srcfmt][t->dstfmt].cost = t->cost;
 176                 }
 177                 t = t->next;
 178         }
 179         do {
 180                 changed = 0;
 181                 /* Don't you just love O(N^3) operations? */
 182                 for (x=0; x< MAX_FORMAT; x++)                           /* For each source format */
 183                         for (y=0; y < MAX_FORMAT; y++)                  /* And each destination format */
 184                                 if (x != y)                                                     /* Except ourselves, of course */
 185                                         for (z=0; z < MAX_FORMAT; z++)  /* And each format it might convert to */
 186                                                 if ((x!=z) && (y!=z))           /* Don't ever convert back to us */
 187                                                         if (tr_matrix[x][y].step && /* We can convert from x to y */
 188                                                                 tr_matrix[y][z].step && /* And from y to z and... */
 189                                                                 (!tr_matrix[x][z].step ||       /* Either there isn't an x->z conversion */
 190                                                                 (tr_matrix[x][y].cost +
 191                                                                  tr_matrix[y][z].cost < /* Or we're cheaper than the existing */
 192                                                                  tr_matrix[x][z].cost)  /* solution */
 193                                                              )) {
 194                                                                                         /* We can get from x to z via y with a cost that
 195                                                                                            is the sum of the transition from x to y and
 196                                                                                            from y to z */
 197
 198                                                                         tr_matrix[x][z].step = tr_matrix[x][y].step;
 199                                                                         tr_matrix[x][z].cost = tr_matrix[x][y].cost +
 200                                                                                                                    tr_matrix[y][z].cost;
 201                                                                         if (option_debug)
 202                                                                                 ast_log(LOG_DEBUG, "Discovered %d cost path from %d to %d, via %d\n", tr_matrix[x][z].cost, x, z, y);
 203                                                                         changed++;
 204                                                                  }
 205
 206         } while (changed);
 207 }
 208
 209 static void calc_cost(struct ast_translator *t)
 210 {
 211         int sofar=0;
 212         struct ast_translator_pvt *pvt;
 213         struct ast_frame *f, *out;
 214         struct timeval start, finish;
 215         int cost;
 216         /* If they don't make samples, give them a terrible score */
 217         if (!t->sample) {
 218                 ast_log(LOG_WARNING, "Translator '%s' does not produce sample frames.\n", t->name);
 219                 t->cost = 99999;
 220                 return;
 221         }
 222         pvt = t->new();
 223         if (!pvt) {
 224                 ast_log(LOG_WARNING, "Translator '%s' appears to be broken and will probably fail.\n", t->name);
 225                 t->cost = 99999;
 226                 return;
 227         }
 228         gettimeofday(&start, NULL);
 229         /* Call the encoder until we've processed one second of time */
 230         while(sofar < 8000) {
 231                 f = t->sample();
 232                 if (!f) {
 233                         ast_log(LOG_WARNING, "Translator '%s' failed to produce a sample frame.\n", t->name);
 234                         t->destroy(pvt);
 235                         t->cost = 99999;
 236                         return;
 237                 }
 238                 t->framein(pvt, f);
 239                 ast_frfree(f);
 240                 while((out = t->frameout(pvt))) {
 241                         sofar += out->samples;
 242                         ast_frfree(out);
 243                 }
 244         }
 245         gettimeofday(&finish, NULL);
 246         t->destroy(pvt);
 247         cost = (finish.tv_sec - start.tv_sec) * 1000 + (finish.tv_usec - start.tv_usec) / 1000;
 248         t->cost = cost;
 249         if (!t->cost)
 250                 t->cost = 1;
 251 }
 252
 253 static int show_translation(int fd, int argc, char *argv[])
 254 {
 255 #define SHOW_TRANS 14
 256         int x,y;
 257         char line[80];
 258         if (argc != 2)
 259                 return RESULT_SHOWUSAGE;
 260         ast_cli(fd, "                        Translation times between formats (in milliseconds)\n");
 261         ast_cli(fd, "                                 Destination Format\n");
 262         ast_pthread_mutex_lock(&list_lock);
 263         for (x=0;x<SHOW_TRANS; x++) {
 264                 if (x == 1)
 265                         strcpy(line, "  Src  ");
 266                 else if (x == 2)
 267                         strcpy(line, "  Fmt  ");
 268                 else
 269                         strcpy(line, "       ");
 270                 for (y=0;y<SHOW_TRANS;y++) {
 271                         if (tr_matrix[x][y].step)
 272                                 snprintf(line + strlen(line), sizeof(line) - strlen(line), " %4d", tr_matrix[x][y].cost);
 273                         else
 274                                 snprintf(line + strlen(line), sizeof(line) - strlen(line), "  n/a");
 275                 }
 276                 snprintf(line + strlen(line), sizeof(line) - strlen(line), "\n");
 277                 ast_cli(fd, line);
 278         }
 279         ast_pthread_mutex_unlock(&list_lock);
 280         return RESULT_SUCCESS;
 281 }
 282
 283 static int added_cli = 0;
 284
 285 static char show_trans_usage[] =
 286 "Usage: show translation\n"
 287 "       Displays known codec translators and the cost associated\n"
 288 "with each conversion.\n";
 289
 290 static struct ast_cli_entry show_trans =
 291 { { "show", "translation", NULL }, show_translation, "Display translation matrix", show_trans_usage };
 292
 293 int ast_register_translator(struct ast_translator *t)
 294 {
 295         char tmp[80];
 296         t->srcfmt = powerof(t->srcfmt);
 297         t->dstfmt = powerof(t->dstfmt);
 298         if ((t->srcfmt >= MAX_FORMAT) || (t->dstfmt >= MAX_FORMAT)) {
 299                 ast_log(LOG_WARNING, "Format %d is larger than MAX_FORMAT\n", t->srcfmt);
 300                 return -1;
 301         }
 302         calc_cost(t);
 303         if (option_verbose > 1)
 304                 ast_verbose(VERBOSE_PREFIX_2 "Registered translator '%s' from format %d to %d, cost %d\n", term_color(tmp, t->name, COLOR_MAGENTA, COLOR_BLACK, sizeof(tmp)), t->srcfmt, t->dstfmt, t->cost);
 305         ast_pthread_mutex_lock(&list_lock);
 306         if (!added_cli) {
 307                 ast_cli_register(&show_trans);
 308                 added_cli++;
 309         }
 310         t->next = list;
 311         list = t;
 312         rebuild_matrix();
 313         ast_pthread_mutex_unlock(&list_lock);
 314         return 0;
 315 }
 316
 317 int ast_unregister_translator(struct ast_translator *t)
 318 {
 319         struct ast_translator *u, *ul = NULL;
 320         ast_pthread_mutex_lock(&list_lock);
 321         u = list;
 322         while(u) {
 323                 if (u == t) {
 324                         if (ul)
 325                                 ul->next = u->next;
 326                         else
 327                                 list = u->next;
 328                         break;
 329                 }
 330                 ul = u;
 331                 u = u->next;
 332         }
 333         rebuild_matrix();
 334         ast_pthread_mutex_unlock(&list_lock);
 335         return (u ? 0 : -1);
 336 }
 337
 338 int ast_translator_best_choice(int *dst, int *srcs)
 339 {
 340         /* Calculate our best source format, given costs, and a desired destination */
 341         int x,y;
 342         int best=-1;
 343         int bestdst=0;
 344         int cur = 1;
 345         int besttime=999999999;
 346         ast_pthread_mutex_lock(&list_lock);
 347         for (y=0;y<MAX_FORMAT;y++) {
 348                 if ((cur & *dst) && (cur & *srcs)) {
 349                         /* This is a common format to both.  Pick it if we don't have one already */
 350                         besttime=0;
 351                         bestdst = cur;
 352                         best = cur;
 353                         break;
 354                 }
 355                 if (cur & *dst)
 356                         for (x=0;x<MAX_FORMAT;x++) {
 357                                 if (tr_matrix[x][y].step &&     /* There's a step */
 358                                  (tr_matrix[x][y].cost < besttime) && /* We're better than what exists now */
 359                                         (*srcs & (1 << x)))                     /* x is a valid source format */
 360                                         {
 361                                                 best = 1 << x;
 362                                                 bestdst = cur;
 363                                                 besttime = tr_matrix[x][y].cost;
 364                                         }
 365                         }
 366                 cur = cur << 1;
 367         }
 368         if (best > -1) {
 369                 *srcs = best;
 370                 *dst = bestdst;
 371                 best = 0;
 372         }
 373         ast_pthread_mutex_unlock(&list_lock);
 374         return best;
 375 }