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