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