vss.c

   1 /*
   2  * Copyright (C) 1997-2007 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file vss.c the virtual streaming system
   8  *
   9  * This contains the audio streaming code of para_server which is independent
  10  * of the current audio format, audio file selector and of the activated
  11  * senders.
  12  */
  13
  14 #include <sys/mman.h> /* mmap */
  15 #include <sys/time.h> /* gettimeofday */
  16 #include <sys/types.h>
  17 #include <dirent.h>
  18
  19 #include "para.h"
  20 #include "error.h"
  21 #include "string.h"
  22 #include "afh.h"
  23 #include "afs.h"
  24 #include "server.h"
  25 #include "net.h"
  26 #include "server.cmdline.h"
  27 #include "afs_common.h"
  28 #include "vss.h"
  29 #include "send.h"
  30 #include "ipc.h"
  31 #include "fd.h"
  32
  33 extern const char *status_item_list[];
  34
  35 static struct timeval announce_tv;
  36 static struct timeval data_send_barrier;
  37 static struct timeval eof_barrier;
  38 static struct timeval autoplay_barrier;
  39
  40 extern struct misc_meta_data *mmd;
  41 extern struct audio_file_selector selectors[];
  42 extern struct sender senders[];
  43
  44 static int audio_file;
  45 static char *map;
  46
  47 /* The mp3 audio format handler does not need any libs. */
  48 void mp3_init(struct audio_format_handler *);
  49
  50 #ifdef HAVE_OGGVORBIS
  51         void ogg_init(struct audio_format_handler *);
  52 #endif
  53 #ifdef HAVE_FAAD
  54         void aac_afh_init(struct audio_format_handler *);
  55 #endif
  56
  57 /**
  58  * The list of supported  audio formats.
  59  *
  60  * We always define the full array of audio formats even if some audio formats
  61  * were not compiled in. This is because for each audio file the number of its
  62  * audio format is stored in the databse. We don't want that numbers to become
  63  * stale just because the user installed a new version of paraslash that
  64  * supports a different set of audio formats.
  65  *
  66  * It can still be easily detected whether an audio format is compiled in by
  67  * checking if the init function pointer is not \p NULL.
  68  */
  69 static struct audio_format_handler afl[] = {
  70         {
  71                 .name = "mp3",
  72                 .init = mp3_init,
  73         },
  74         {
  75                 .name = "ogg",
  76 #ifdef HAVE_OGGVORBIS
  77                 .init = ogg_init,
  78 #endif
  79         },
  80         {
  81                 .name = "aac",
  82 #ifdef HAVE_FAAD
  83                 .init = aac_afh_init,
  84 #endif
  85         },
  86         {
  87                 .name = NULL,
  88         }
  89 };
  90
  91 static inline int next_audio_format(int format)
  92 {
  93         for (;;) {
  94                 if (!afl[format].name)
  95                         return format;
  96                 format++;
  97                 if (afl[format].init)
  98                         return format;
  99         }
 100
 101 }
 102
 103 /** Iterate over each supported audio format. */
 104 #define FOR_EACH_AUDIO_FORMAT(i) for (i = 0; afl[i].name; i = next_audio_format(i))
 105
 106
 107 /**
 108  * check if vss status flag \a P (playing) is set
 109  *
 110  * \return greater than zero if playing, zero otherwise.
 111  *
 112  */
 113 unsigned int vss_playing(void)
 114 {
 115         return mmd->new_vss_status_flags & VSS_PLAYING;
 116 }
 117
 118 /**
 119  * check if \a N (next) status flag is set
 120  *
 121  * \return greater than zero if set, zero if not.
 122  *
 123  */
 124 unsigned int vss_next(void)
 125 {
 126         return mmd->new_vss_status_flags & VSS_NEXT;
 127 }
 128
 129 /**
 130  * check if a reposition request is pending
 131  *
 132  * \return greater than zero if true, zero otherwise.
 133  *
 134  */
 135 unsigned int vss_repos(void)
 136 {
 137         return mmd->new_vss_status_flags & VSS_REPOS;
 138 }
 139
 140 /**
 141  * check if the vss is currently paused
 142  *
 143  * \return greater than zero if paused, zero otherwise.
 144  *
 145  */
 146 unsigned int vss_paused(void)
 147 {
 148         return !(mmd->new_vss_status_flags & VSS_NEXT)
 149                 && !(mmd->new_vss_status_flags & VSS_PLAYING);
 150 }
 151
 152 /**
 153  * Get the name of the given audio format.
 154  *
 155  * \param i The audio format number.
 156  *
 157  * This returns a pointer to statically allocated memory so it
 158  * must not be freed by the caller.
 159  */
 160 const char *audio_format_name(int i)
 161 {
 162         //PARA_NOTICE_LOG("array size: %u¸ requested: %d\n", ARRAY_SIZE(afl), i);
 163         assert(i < 0 || i < ARRAY_SIZE(afl) - 1);
 164         return i >= 0?  afl[i].name : "(none)";
 165 }
 166
 167 /**
 168  * initialize the virtual streaming system
 169  *
 170  * Call the init functions of all supported audio format handlers and
 171  * initialize all supported senders.
 172  */
 173 void vss_init(void)
 174 {
 175         int i;
 176         char *hn = para_hostname(), *home = para_homedir();
 177         long unsigned announce_time = conf.announce_time_arg > 0?
 178                         conf.announce_time_arg : 300,
 179                 autoplay_delay = conf.autoplay_delay_arg > 0?
 180                         conf.autoplay_delay_arg : 0;
 181
 182         PARA_DEBUG_LOG("supported audio formats: %s\n",
 183                 SUPPORTED_AUDIO_FORMATS);
 184         FOR_EACH_AUDIO_FORMAT(i) {
 185                 PARA_NOTICE_LOG("initializing %s handler\n",
 186                         afl[i].name);
 187                 afl[i].init(&afl[i]);
 188         }
 189         ms2tv(announce_time, &announce_tv);
 190         PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&announce_tv));
 191         for (i = 0; senders[i].name; i++) {
 192                 PARA_NOTICE_LOG("initializing %s sender\n", senders[i].name);
 193                 senders[i].init(&senders[i]);
 194         }
 195         free(hn);
 196         free(home);
 197         if (conf.autoplay_given) {
 198                 struct timeval now, tmp;
 199                 mmd->vss_status_flags |= VSS_PLAYING;
 200                 mmd->new_vss_status_flags |= VSS_PLAYING;
 201                 gettimeofday(&now, NULL);
 202                 ms2tv(autoplay_delay, &tmp);
 203                 tv_add(&now, &tmp, &autoplay_barrier);
 204         }
 205 }
 206
 207 static int get_file_info(int i)
 208 {
 209         return  afl[i].get_file_info(map, mmd->size, &mmd->afi);
 210 }
 211
 212 /**
 213  * guess the audio format judging from filename
 214  *
 215  * \param name the filename
 216  *
 217  * \return This function returns -1 if it has no idea what kind of audio
 218  * file this might be. Otherwise the (non-negative) number of the audio format
 219  * is returned.
 220  */
 221 int guess_audio_format(const char *name)
 222 {
 223         int i,j, len = strlen(name);
 224
 225         FOR_EACH_AUDIO_FORMAT(i) {
 226                 for (j = 0; afl[i].suffixes[j]; j++) {
 227                         const char *p = afl[i].suffixes[j];
 228                         int plen = strlen(p);
 229                         if (len < plen + 1)
 230                                 continue;
 231                         if (name[len - plen - 1] != '.')
 232                                 continue;
 233                         if (strcasecmp(name + len - plen, p))
 234                                 continue;
 235 //                      PARA_DEBUG_LOG("might be %s\n", audio_format_name(i));
 236                         return i;
 237                 }
 238         }
 239         return -E_BAD_AUDIO_FILE_SUFFIX;
 240 }
 241
 242 static int get_audio_format(int omit)
 243 {
 244         int i;
 245
 246         FOR_EACH_AUDIO_FORMAT(i) {
 247                 if (i == omit)
 248                         continue;
 249                 if (get_file_info(i) > 0)
 250                         return i;
 251         }
 252         return -E_AUDIO_FORMAT;
 253 }
 254
 255 /**
 256  * Call get_file_info() to obtain an afhi structure.
 257  *
 258  * \param path The full path of the audio file.
 259  * \param data Pointer to the contents of the (mapped) file.
 260  * \param size The file size in bytes.
 261  * \param afhi Result pointer.
 262  *
 263  * \return The number of the audio format on success, \p -E_AUDIO_FORMAT if no
 264  * compiled in audio format handler is able to handler the file.
 265  *
 266  * This function tries to find an audio format handler that can interpret the
 267  * file given by \a data and \a size.
 268  *
 269  * It first tries to determine the audio format from the filename given by \a
 270  * path. If this doesn't work, all other audio format handlers are tried until
 271  * one is found that can handle the file.
 272  */
 273 int compute_afhi(const char *path, char *data, size_t size,
 274                 struct audio_format_info *afhi)
 275 {
 276         int ret, i, format = guess_audio_format(path);
 277
 278         if (format >= 0) {
 279                 ret = afl[format].get_file_info(data, size, afhi);
 280                 if (ret >= 0)
 281                         return format;
 282         }
 283         FOR_EACH_AUDIO_FORMAT(i) {
 284                 if (i == format) /* we already tried this one to no avail */
 285                         continue;
 286                 ret = afl[i].get_file_info(data, size, afhi);
 287                 if (ret >= 0)
 288                         return i;
 289                 PARA_WARNING_LOG("%s\n", PARA_STRERROR(-ret));
 290         }
 291         return -E_AUDIO_FORMAT;
 292 }
 293
 294 /*
 295  * upddate shared mem
 296  */
 297 static int update_mmd(void)
 298 {
 299         int i;
 300
 301         i = guess_audio_format(mmd->filename);
 302         if (i < 0 || get_file_info(i) < 0)
 303                 i = get_audio_format(i);
 304         if (i < 0)
 305                 return i;
 306         mmd->audio_format = i;
 307         mmd->chunks_sent = 0;
 308         mmd->current_chunk = 0;
 309         mmd->offset = 0;
 310         mmd->events++;
 311         return 1;
 312 }
 313
 314 static void vss_get_audio_file(void)
 315 {
 316         char **sl = selectors[mmd->selector_num].get_audio_file_list(10);
 317         int i;
 318         struct stat file_status;
 319
 320         if (!sl)
 321                 goto err_out;
 322         for (i = 0; sl[i]; i++) {
 323                 struct timeval now;
 324                 PARA_INFO_LOG("trying %s\n", sl[i]);
 325                 if (strlen(sl[i]) >= _POSIX_PATH_MAX)
 326                         continue;
 327                 audio_file = open(sl[i], O_RDONLY);
 328                 if (audio_file < 0)
 329                         continue;
 330                 if (fstat(audio_file, &file_status) == -1 ||
 331                                 !file_status.st_size) {
 332                         close(audio_file);
 333                         continue;
 334                 }
 335                 mmd->size = file_status.st_size;
 336                 mmd->mtime = file_status.st_mtime;
 337                 map = para_mmap(mmd->size, PROT_READ, MAP_PRIVATE,
 338                         audio_file, 0);
 339                 strcpy(mmd->filename, sl[i]);
 340                 mmd->afi.header_len = 0; /* default: no header */
 341                 if (update_mmd() < 0) { /* invalid file */
 342                         close(audio_file);
 343                         munmap(map, mmd->size);
 344                         map = NULL;
 345                         continue;
 346                 }
 347                 mmd->num_played++;
 348                 if (selectors[mmd->selector_num].update_audio_file)
 349                         selectors[mmd->selector_num].update_audio_file(sl[i]);
 350                 PARA_NOTICE_LOG("next audio file: %s\n", mmd->filename);
 351                 mmd->new_vss_status_flags &= (~VSS_NEXT);
 352                 gettimeofday(&now, NULL);
 353                 tv_add(&now, &announce_tv, &data_send_barrier);
 354                 goto free;
 355         }
 356 err_out:
 357         PARA_ERROR_LOG("%s", "no valid files found\n");
 358         mmd->new_vss_status_flags = VSS_NEXT;
 359 free:
 360         if (sl) {
 361                 for (i = 0; sl[i]; i++)
 362                         free(sl[i]);
 363                 free(sl);
 364         }
 365 }
 366
 367 static int chk_barrier(const char *bname, const struct timeval *now,
 368                 const struct timeval *barrier, struct timeval *diff,
 369                 int print_log)
 370 {
 371         long ms;
 372
 373         if (tv_diff(now, barrier, diff) > 0)
 374                 return 1;
 375         ms = tv2ms(diff);
 376         if (print_log && ms)
 377                 PARA_DEBUG_LOG("%s barrier: %lims left\n", bname, ms);
 378         return -1;
 379 }
 380
 381 static void vss_next_chunk_time(struct timeval *due)
 382 {
 383         struct timeval tmp;
 384
 385         tv_scale(mmd->chunks_sent, &mmd->afi.chunk_tv, &tmp);
 386         tv_add(&tmp, &mmd->stream_start, due);
 387 }
 388
 389 /*
 390  * != NULL: timeout for next chunk
 391  * NULL: nothing to do
 392  */
 393 static struct timeval *vss_compute_timeout(void)
 394 {
 395         static struct timeval the_timeout;
 396         struct timeval now, next_chunk;
 397
 398         if (vss_next() && mmd->audio_format >= 0) {
 399                 /* only sleep a bit, nec*/
 400                 the_timeout.tv_sec = 0;
 401                 the_timeout.tv_usec = 100;
 402                 return &the_timeout;
 403         }
 404         gettimeofday(&now, NULL);
 405         if (chk_barrier("autoplay_delay", &now, &autoplay_barrier,
 406                         &the_timeout, 1) < 0)
 407                 return &the_timeout;
 408         if (chk_barrier("eof", &now, &eof_barrier, &the_timeout, 1) < 0)
 409                 return &the_timeout;
 410         if (chk_barrier("data send", &now, &data_send_barrier,
 411                         &the_timeout, 1) < 0)
 412                 return &the_timeout;
 413         if (mmd->audio_format < 0 || !vss_playing() || !map)
 414                 return NULL;
 415         vss_next_chunk_time(&next_chunk);
 416         if (chk_barrier(afl[mmd->audio_format].name, &now, &next_chunk,
 417                         &the_timeout, 0) < 0)
 418                 return &the_timeout;
 419         /* chunk is due or bof */
 420         the_timeout.tv_sec = 0;
 421         the_timeout.tv_usec = 0;
 422         return &the_timeout;
 423 }
 424
 425 static void vss_eof(void)
 426 {
 427         struct timeval now;
 428         int i;
 429         char *tmp;
 430
 431         if (!map) {
 432                 for (i = 0; senders[i].name; i++)
 433                         senders[i].shutdown_clients();
 434                 return;
 435         }
 436         gettimeofday(&now, NULL);
 437         tv_add(&mmd->afi.eof_tv, &now, &eof_barrier);
 438         munmap(map, mmd->size);
 439         map = NULL;
 440         close(audio_file);
 441         mmd->audio_format = -1;
 442         mmd->chunks_sent = 0;
 443         mmd->offset = 0;
 444         mmd->afi.seconds_total = 0;
 445         free(mmd->afi.chunk_table);
 446         mmd->afi.chunk_table = NULL;
 447         tmp  = make_message("%s:\n%s:\n%s:\n", status_item_list[SI_AUDIO_INFO1],
 448                 status_item_list[SI_AUDIO_INFO2], status_item_list[SI_AUDIO_INFO3]);
 449         strcpy(mmd->afi.info_string, tmp);
 450         free(tmp);
 451         tmp  = make_message("%s:\n%s:\n%s:\n", status_item_list[SI_DBINFO1],
 452                 status_item_list[SI_DBINFO2], status_item_list[SI_DBINFO3]);
 453         strcpy(mmd->selector_info, tmp);
 454         free(tmp);
 455         mmd->filename[0] = '\0';
 456         mmd->size = 0;
 457         mmd->events++;
 458 }
 459
 460 /**
 461  * Get the header of the current audio file.
 462  *
 463  * \param header_len the length of the header is stored here
 464  *
 465  * \return a pointer to a buffer containing the header, or NULL, if no audio
 466  * file is selected or if the current audio format does not need special header
 467  * treamtment.
 468  *
 469  */
 470 char *vss_get_header(size_t *header_len)
 471 {
 472         if (mmd->audio_format < 0 || !map || !mmd->afi.header_len)
 473                 return NULL;
 474         *header_len = mmd->afi.header_len;
 475         return map + mmd->afi.header_offset;
 476 }
 477
 478 /**
 479  * get the list of all supported audio formats
 480  *
 481  * \return a space separated list of all supported audio formats
 482  * It is not allocated at runtime, i.e. there is no need to free
 483  * the returned string in the caller.
 484  */
 485 const char *supported_audio_formats(void)
 486 {
 487         return SUPPORTED_AUDIO_FORMATS;
 488 }
 489
 490 /**
 491  * get the chunk time of the current audio file
 492  *
 493  * \return a pointer to a struct containing the chunk time, or NULL,
 494  * if currently no audio file is selected.
 495  */
 496 struct timeval *vss_chunk_time(void)
 497 {
 498         if (mmd->audio_format < 0)
 499                 return NULL;
 500         return &mmd->afi.chunk_tv;
 501 }
 502
 503 enum afs_socket_status {
 504         AFS_SOCKET_READY,
 505         AFS_SOCKET_CHECK_FOR_WRITE,
 506         AFS_SOCKET_AFD_PENDING
 507 };
 508
 509 static enum afs_socket_status afsss;
 510
 511 /**
 512  * compute the timeout for para_server's main select-loop
 513  *
 514  * This function gets called from para_server to determine the timeout value
 515  * for its main select loop.
 516  *
 517  * Before the timeout is computed, the current vss status flags are evaluated
 518  * and acted upon by calling appropriate functions from the lower layers.
 519  * Possible actions include
 520  *
 521  *      - request a new file list from the current audio file selector
 522  *      - shutdown of all senders (stop/pause command)
 523  *      - reposition the stream (ff/jmp command)
 524  *
 525  * \return A pointer to a struct timeval containing the timeout for the next
 526  * chunk of data to be sent, or NULL if we're not sending right now.
 527  */
 528 struct timeval *vss_preselect(fd_set *rfds, fd_set *wfds, int *max_fileno)
 529 {
 530         struct audio_format_handler *af = NULL;
 531         int i, format;
 532         struct timeval *ret;
 533
 534         para_fd_set(afs_socket, rfds, max_fileno);
 535
 536 //again:
 537         format = mmd->audio_format;
 538         if (format >= 0)
 539                 af = afl + format;
 540         else
 541                 for (i = 0; senders[i].name; i++)
 542                         senders[i].shutdown_clients();
 543         if (vss_next() && af) {
 544                 vss_eof();
 545                 return vss_compute_timeout();
 546         }
 547         if (vss_paused() || vss_repos()) {
 548                 for (i = 0; senders[i].name; i++)
 549                         senders[i].shutdown_clients();
 550                 if (af) {
 551                         struct timeval now;
 552                         gettimeofday(&now, NULL);
 553                         if (!vss_paused() || mmd->chunks_sent)
 554                                 tv_add(&mmd->afi.eof_tv, &now, &eof_barrier);
 555                         if (vss_repos())
 556                                 tv_add(&now, &announce_tv, &data_send_barrier);
 557                         if (mmd->new_vss_status_flags & VSS_NOMORE)
 558                                 mmd->new_vss_status_flags = VSS_NEXT;
 559                 }
 560                 mmd->chunks_sent = 0;
 561         }
 562         if (vss_repos()) {
 563                 mmd->new_vss_status_flags &= ~(VSS_REPOS);
 564                 mmd->current_chunk = mmd->repos_request;
 565         }
 566         ret = vss_compute_timeout();
 567         if (!ret && !map && vss_playing() &&
 568                         !(mmd->new_vss_status_flags & VSS_NOMORE)) {
 569                 PARA_DEBUG_LOG("%s", "ready and playing, but no audio file\n");
 570                 //vss_get_audio_file();
 571                 if (afsss == AFS_SOCKET_READY) {
 572                         para_fd_set(afs_socket, wfds, max_fileno);
 573                         afsss = AFS_SOCKET_CHECK_FOR_WRITE;
 574                 }
 575 //              goto again;
 576         }
 577         return ret;
 578 }
 579
 580 static int recv_afs_msg(int *fd, uint32_t *code, uint32_t *data)
 581 {
 582         char control[255], buf[8];
 583         struct msghdr msg = {.msg_iov = NULL};
 584         struct cmsghdr *cmsg;
 585         struct iovec iov;
 586         int ret = 0;
 587
 588         iov.iov_base = buf;
 589         iov.iov_len = sizeof(buf);
 590         msg.msg_iov = &iov;
 591         msg.msg_iovlen = 1;
 592         msg.msg_control = control;
 593         msg.msg_controllen = sizeof(control);
 594         memset(buf, 0, sizeof(buf));
 595         ret = recvmsg(afs_socket, &msg, 0);
 596         if (ret < 0)
 597                 return -ERRNO_TO_PARA_ERROR(errno);
 598         if (iov.iov_len != sizeof(buf))
 599                 return -E_SHORT_AFS_READ;
 600         *code = *(uint32_t*)buf;
 601         *data =  *(uint32_t*)(buf + 4);
 602         cmsg = CMSG_FIRSTHDR(&msg);
 603         for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
 604                 if (cmsg->cmsg_level != SOL_SOCKET
 605                         || cmsg->cmsg_type != SCM_RIGHTS)
 606                 continue;
 607                 if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
 608                 continue;
 609                 *fd = *(int *)CMSG_DATA(cmsg);
 610         }
 611         return 1;
 612 }
 613
 614 static void recv_afs_result(void)
 615 {
 616         int ret, passed_fd = -1, shmid;
 617         uint32_t afs_code = 0, afs_data = 0;
 618         struct stat statbuf;
 619         struct timeval now;
 620
 621         ret = recv_afs_msg(&passed_fd, &afs_code, &afs_data);
 622         if (ret < 0)
 623                 goto err;
 624         PARA_NOTICE_LOG("got the fd: %d, code: %u, shmid: %u\n",
 625                 passed_fd, afs_code, afs_data);
 626         ret = -E_BAD_AFS_CODE;
 627         if (afs_code != NEXT_AUDIO_FILE)
 628                 goto err;
 629         afsss = AFS_SOCKET_READY;
 630         shmid = afs_data;
 631         ret = load_afd(shmid, &mmd->afd);
 632         if (ret < 0)
 633                 goto err;
 634         shm_destroy(shmid);
 635         PARA_NOTICE_LOG("next audio file: %s (%lu chunks)\n", mmd->afd.path,
 636                 mmd->afd.afhi.chunks_total);
 637         ret = fstat(passed_fd, &statbuf);
 638         if (ret < 0) {
 639                 ret = -ERRNO_TO_PARA_ERROR(errno);
 640                 goto err;
 641         }
 642         mmd->size = statbuf.st_size;
 643         mmd->mtime = statbuf.st_mtime;
 644         map = para_mmap(mmd->size, PROT_READ, MAP_PRIVATE,
 645                 passed_fd, 0);
 646         strcpy(mmd->filename, mmd->afd.path); /* FIXME: check length */
 647         mmd->afi.header_len = 0; /* default: no header */
 648         mmd->audio_format = mmd->afd.afsi.audio_format_id;
 649         mmd->chunks_sent = 0;
 650         mmd->current_chunk = 0;
 651         mmd->offset = 0;
 652         mmd->events++;
 653         mmd->num_played++;
 654         mmd->afi = mmd->afd.afhi;
 655         mmd->new_vss_status_flags &= (~VSS_NEXT);
 656         gettimeofday(&now, NULL);
 657         tv_add(&now, &announce_tv, &data_send_barrier);
 658         return;
 659 err:
 660         if (passed_fd >= 0)
 661                 close(passed_fd);
 662         PARA_ERROR_LOG("%s\n", PARA_STRERROR(-ret));
 663 }
 664
 665 void vss_post_select(fd_set *rfds, fd_set *wfds)
 666 {
 667         int ret;
 668
 669         if (FD_ISSET(afs_socket, rfds))
 670                 recv_afs_result();
 671         if (afsss != AFS_SOCKET_CHECK_FOR_WRITE || !FD_ISSET(afs_socket, wfds))
 672                 return;
 673         ret = send_buffer(afs_socket, "new");
 674         afsss = AFS_SOCKET_AFD_PENDING;
 675 }
 676
 677 static void get_chunk(long unsigned chunk_num, char **buf, size_t *len)
 678 {
 679         size_t pos = mmd->afi.chunk_table[chunk_num];
 680         *buf = map + pos;
 681         *len = mmd->afi.chunk_table[chunk_num + 1] - pos;
 682 }
 683
 684 /**
 685  * Get the data of the given chunk.
 686  *
 687  * \param chunk_num The number of the desired chunk.
 688  * \param buf Chunk data.
 689  * \param len Chunk length in bytes.
 690  *
 691  * \return Positive on success, negative on errors.
 692  */
 693 int vss_get_chunk(long unsigned chunk_num, char **buf, size_t *len)
 694 {
 695         if (mmd->audio_format < 0 || !map || !vss_playing())
 696                 return -E_CHUNK;
 697         if (chunk_num >= mmd->afi.chunks_total)
 698                 return -E_CHUNK;
 699         get_chunk(chunk_num, buf, len);
 700         return 1;
 701 }
 702
 703 /**
 704  * main sending function
 705  *
 706  * This function gets called from para_server as soon as the next chunk of
 707  * data should be pushed out. It first calls the read_chunk() function of
 708  * the current audio format handler to obtain a pointer to the data to be
 709  * sent out as well as its length. This information is then passed to each
 710  * supported sender's send() function which does the actual sending.
 711  */
 712 void vss_send_chunk(void)
 713 {
 714         int i;
 715         struct audio_format_handler *af;
 716         struct timeval now, due;
 717
 718         if (mmd->audio_format < 0 || !map || !vss_playing())
 719                 return;
 720         af = &afl[mmd->audio_format];
 721         gettimeofday(&now, NULL);
 722         vss_next_chunk_time(&due);
 723         if (tv_diff(&due, &now, NULL) > 0)
 724                 return;
 725         if (chk_barrier("eof", &now, &eof_barrier, &due, 1) < 0)
 726                 return;
 727         if (chk_barrier("data send", &now, &data_send_barrier,
 728                         &due, 1) < 0)
 729                 return;
 730         mmd->new_vss_status_flags &= ~VSS_REPOS;
 731         if (mmd->current_chunk >= mmd->afi.chunks_total) { /* eof */
 732                 mmd->new_vss_status_flags |= VSS_NEXT;
 733                 return vss_eof();
 734         }
 735         /*
 736          * We call the send function also in case of empty chunks as they
 737          * might have still some data queued which can be sent in this case.
 738          */
 739         if (!mmd->chunks_sent) {
 740                 struct timeval tmp;
 741                 gettimeofday(&mmd->stream_start, NULL);
 742                 tv_scale(mmd->current_chunk, &mmd->afi.chunk_tv, &tmp);
 743                 mmd->offset = tv2ms(&tmp);
 744                 mmd->events++;
 745         }
 746         for (i = 0; senders[i].name; i++) {
 747                 char *buf;
 748                 size_t len;
 749                 get_chunk(mmd->current_chunk, &buf, &len);
 750                 senders[i].send(mmd->current_chunk, mmd->chunks_sent, buf, len);
 751         }
 752         mmd->new_vss_status_flags |= VSS_PLAYING;
 753         mmd->chunks_sent++;
 754         mmd->current_chunk++;
 755 }