2 * Copyright (C) 1997 Andre Noll <maan@tuebingen.mpg.de>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file vss.c The virtual streaming system.
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
14 #include <sys/socket.h>
15 #include <netinet/in.h>
18 #include <sys/types.h>
19 #include <arpa/inet.h>
25 #include "portable_io.h"
32 #include "server.cmdline.h"
40 extern struct misc_meta_data *mmd;
42 extern void dccp_send_init(struct sender *);
43 extern void http_send_init(struct sender *);
44 extern void udp_send_init(struct sender *);
46 /** The list of supported senders. */
47 struct sender senders[] = {
50 .init = http_send_init,
54 .init = dccp_send_init,
58 .init = udp_send_init,
65 /** The possible states of the afs socket. */
66 enum afs_socket_status {
67 /** Socket is inactive. */
69 /** Socket fd was included in the write fd set for select(). */
70 AFS_SOCKET_CHECK_FOR_WRITE,
71 /** vss wrote a request to the socket and waits for reply from afs. */
72 AFS_SOCKET_AFD_PENDING
75 /** The task structure for the virtual streaming system. */
77 /** Copied from the -announce_time command line option. */
78 struct timeval announce_tv;
79 /** End of the announcing interval. */
80 struct timeval data_send_barrier;
81 /** End of the EOF interval. */
82 struct timeval eof_barrier;
83 /** Only used if --autoplay_delay was given. */
84 struct timeval autoplay_barrier;
85 /** Used for afs-server communication. */
87 /** The current state of \a afs_socket. */
88 enum afs_socket_status afsss;
89 /** The memory mapped audio file. */
91 /** The size of the memory mapping. */
93 /** Used by the scheduler. */
95 /** Pointer to the header of the mapped audio file. */
97 /** Length of the audio file header. */
99 /** Time between audio file headers are sent. */
100 struct timeval header_interval;
104 * The list of currently connected fec clients.
106 * Senders may use \ref vss_add_fec_client() to add entries to the list.
108 static struct list_head fec_client_list;
111 * Data associated with one FEC group.
113 * A FEC group consists of a fixed number of slices and this number is given by
114 * the \a slices_per_group parameter of struct \ref fec_client_parms. Each FEC
115 * group contains a number of chunks of the current audio file.
117 * FEC slices directly correspond to the data packages sent by the paraslash
118 * senders that use FEC. Each slice is identified by its group number and its
119 * number within the group. All slices have the same size, but the last slice
120 * of the group may not be filled entirely.
123 /** The number of the FEC group. */
125 /** Number of bytes in this group. */
127 /** The first chunk of the current audio file belonging to the group. */
128 uint32_t first_chunk;
129 /** The number of chunks contained in this group. */
131 /** When the first chunk was sent. */
132 struct timeval start;
133 /** The duration of the full group. */
134 struct timeval duration;
135 /** The group duration divided by the number of slices. */
136 struct timeval slice_duration;
137 /** Group contains the audio file header that occupies that many slices. */
138 uint8_t num_header_slices;
139 /** Number of bytes per slice for this group. */
140 uint16_t slice_bytes;
143 /** A FEC client is always in one of these states. */
144 enum fec_client_state {
145 FEC_STATE_NONE = 0, /**< not initialized and not enabled */
146 FEC_STATE_DISABLED, /**< temporarily disabled */
147 FEC_STATE_READY_TO_RUN /**< initialized and enabled */
151 * Describes one connected FEC client.
154 /** Current state of the client */
155 enum fec_client_state state;
156 /** The connected sender client (transport layer). */
157 struct sender_client *sc;
158 /** Parameters requested by the client. */
159 struct fec_client_parms *fcp;
160 /** Used by the core FEC code. */
161 struct fec_parms *parms;
162 /** The position of this client in the fec client list. */
163 struct list_head node;
164 /** When the first slice for this client was sent. */
165 struct timeval stream_start;
166 /** The first chunk sent to this FEC client. */
167 int first_stream_chunk;
168 /** Describes the current group. */
169 struct fec_group group;
170 /** The current slice. */
171 uint8_t current_slice_num;
172 /** The data to be FEC-encoded (point to a region within the mapped audio file). */
173 const unsigned char **src_data;
174 /** Last time an audio header was sent. */
175 struct timeval next_header_time;
176 /** Used for the last source pointer of an audio file. */
177 unsigned char *extra_src_buf;
178 /** Needed for the last slice of the audio file header. */
179 unsigned char *extra_header_buf;
180 /** Extra slices needed to store largest chunk + header. */
181 int num_extra_slices;
182 /** Contains the FEC-encoded data. */
183 unsigned char *enc_buf;
184 /** Maximal packet size. */
189 * Get the chunk time of the current audio file.
191 * \return A pointer to a struct containing the chunk time, or NULL,
192 * if currently no audio file is selected.
194 struct timeval *vss_chunk_time(void)
196 if (mmd->afd.afhi.chunk_tv.tv_sec == 0 &&
197 mmd->afd.afhi.chunk_tv.tv_usec == 0)
199 return &mmd->afd.afhi.chunk_tv;
203 * Write a fec header to a buffer.
205 * \param buf The buffer to write to.
206 * \param h The fec header to write.
208 static void write_fec_header(struct fec_client *fc, struct vss_task *vsst)
210 char *buf = (char *)fc->enc_buf;
211 struct fec_group *g = &fc->group;
212 struct fec_client_parms *p = fc->fcp;
214 write_u32(buf, FEC_MAGIC);
216 write_u8(buf + 4, p->slices_per_group + fc->num_extra_slices);
217 write_u8(buf + 5, p->data_slices_per_group + fc->num_extra_slices);
218 write_u32(buf + 6, g->num_header_slices? vsst->header_len : 0);
220 write_u32(buf + 10, g->num);
221 write_u32(buf + 14, g->bytes);
223 write_u8(buf + 18, fc->current_slice_num);
224 write_u8(buf + 19, 0); /* unused */
225 write_u16(buf + 20, g->slice_bytes);
226 write_u8(buf + 22, g->first_chunk? 0 : 1);
227 write_u8(buf + 23, vsst->header_len? 1 : 0);
228 memset(buf + 24, 0, 8);
231 static bool need_audio_header(struct fec_client *fc, struct vss_task *vsst)
233 if (!mmd->current_chunk) {
234 tv_add(now, &vsst->header_interval, &fc->next_header_time);
237 if (!vsst->header_buf)
239 if (vsst->header_len == 0)
241 if (fc->group.num > 0) {
242 if (!fc->fcp->need_periodic_header)
244 if (tv_diff(&fc->next_header_time, now, NULL) > 0)
247 tv_add(now, &vsst->header_interval, &fc->next_header_time);
251 static bool need_data_slices(struct fec_client *fc, struct vss_task *vsst)
253 if (fc->group.num > 0)
255 if (!vsst->header_buf)
257 if (vsst->header_len == 0)
259 if (fc->fcp->need_periodic_header)
264 static int num_slices(long unsigned bytes, int max_payload, int rs)
268 assert(max_payload > 0);
270 ret = DIV_ROUND_UP(bytes, max_payload);
276 /* set group start and group duration */
277 static void set_group_timing(struct fec_client *fc, struct vss_task *vsst)
279 struct fec_group *g = &fc->group;
280 struct timeval *chunk_tv = vss_chunk_time();
282 if (!need_data_slices(fc, vsst))
283 ms2tv(200, &g->duration);
285 tv_scale(g->num_chunks, chunk_tv, &g->duration);
286 tv_divide(fc->fcp->slices_per_group + fc->num_extra_slices,
287 &g->duration, &g->slice_duration);
288 PARA_DEBUG_LOG("durations (group/chunk/slice): %lu/%lu/%lu\n",
289 tv2ms(&g->duration), tv2ms(chunk_tv), tv2ms(&g->slice_duration));
292 static int initialize_fec_client(struct fec_client *fc, struct vss_task *vsst)
295 int hs, ds, rs; /* header/data/redundant slices */
296 struct fec_client_parms *fcp = fc->fcp;
301 * Set the maximum slice size to the Maximum Packet Size if the
302 * transport protocol allows to determine this value. The user
303 * can specify a slice size up to this value.
305 ret = fcp->init_fec(fc->sc);
310 fc->mps = generic_max_transport_msg_size(fc->sc->fd);
311 if (fc->mps <= FEC_HEADER_SIZE)
312 return -ERRNO_TO_PARA_ERROR(EINVAL);
314 rs = fc->fcp->slices_per_group - fc->fcp->data_slices_per_group;
315 ret = num_slices(vsst->header_len, fc->mps - FEC_HEADER_SIZE, rs);
319 ret = num_slices(mmd->afd.max_chunk_size, fc->mps - FEC_HEADER_SIZE, rs);
323 if (fc->fcp->need_periodic_header)
326 k = PARA_MAX(hs, ds);
327 if (k < fc->fcp->data_slices_per_group)
328 k = fc->fcp->data_slices_per_group;
329 fc->num_extra_slices = k - fc->fcp->data_slices_per_group;
332 ret = fec_new(k, n, &fc->parms);
335 PARA_INFO_LOG("mps: %d, k: %d, n: %d, extra slices: %d\n",
336 fc->mps, k, n, fc->num_extra_slices);
337 fc->src_data = para_realloc(fc->src_data, k * sizeof(char *));
338 fc->enc_buf = para_realloc(fc->enc_buf, fc->mps);
339 fc->extra_src_buf = para_realloc(fc->extra_src_buf, fc->mps);
340 fc->extra_header_buf = para_realloc(fc->extra_header_buf, fc->mps);
342 fc->state = FEC_STATE_READY_TO_RUN;
343 fc->next_header_time.tv_sec = 0;
344 fc->stream_start = *now;
345 fc->first_stream_chunk = mmd->current_chunk;
349 static void vss_get_chunk(int chunk_num, struct vss_task *vsst,
350 char **buf, size_t *sz)
353 * Chunk zero is special for header streams: It is the first portion of
354 * the audio file which consists of the audio file header. It may be
355 * arbitrary large due to embedded meta data. Audio format handlers may
356 * replace the header by a stripped one with meta data omitted which is
357 * of bounded size. We always use the stripped header for streaming
358 * rather than the unmodified header (chunk zero).
360 if (chunk_num == 0 && vsst->header_len > 0) {
361 *buf = vsst->header_buf; /* stripped header */
362 *sz = vsst->header_len;
365 afh_get_chunk(chunk_num, &mmd->afd.afhi, vsst->map, (const char **)buf,
369 static void compute_group_size(struct vss_task *vsst, struct fec_group *g,
374 int i, max_chunks = PARA_MAX(1LU, 150 / tv2ms(vss_chunk_time()));
376 if (g->first_chunk == 0) {
378 vss_get_chunk(0, vsst, &buf, &len);
386 * Include chunks into the group until the group duration is at least
387 * 150ms. For ogg and wma, a single chunk's duration (ogg page/wma
388 * super frame) is already larger than 150ms, so a FEC group consists
389 * of exactly one chunk for these audio formats.
392 int chunk_num = g->first_chunk + i;
394 if (g->bytes > 0 && i >= max_chunks) /* duration limit */
396 if (chunk_num >= mmd->afd.afhi.chunks_total) /* eof */
398 vss_get_chunk(chunk_num, vsst, &buf, &len);
399 if (g->bytes + len > max_bytes)
401 /* Include this chunk */
405 assert(g->num_chunks);
409 * Compute the slice size of the next group.
411 * The FEC parameters n and k are fixed but the slice size varies per
412 * FEC group. We'd like to choose slices as small as possible to avoid
413 * unnecessary FEC calculations but large enough to guarantee that the
414 * k data slices suffice to encode the header (if needed) and the data
417 * Once we know the payload of the next group, we define the number s
418 * of bytes per slice for this group by
420 * s = ceil(payload / k)
422 * However, for header streams, computing s is more complicated since no
423 * overlapping of header and data slices is possible. Hence we have k >=
424 * 2 and s must satisfy
426 * (*) ceil(h / s) + ceil(d / s) <= k
428 * where h and d are payload of the header and the data chunk(s)
429 * respectively. In general there is no value for s such that (*)
430 * becomes an equality, for example if h = 4000, d = 5000 and k = 10.
432 * We use the following approach for computing a suitable value for s:
435 * k1 := ceil(k * min(h, d) / (h + d)),
438 * Note that k >= 2 implies k1 > 0 and k2 > 0, so
440 * s := max(ceil(min(h, d) / k1), ceil(max(h, d) / k2))
442 * is well-defined. Inequality (*) holds for this value of s since k1
443 * slices suffice to store min(h, d) while k2 slices suffice to store
444 * max(h, d), i.e. the first addent of (*) is bounded by k1 and the
447 * For the above example we obtain
449 * k1 = ceil(10 * 4000 / 9000) = 5, k2 = 5,
450 * s = max(4000 / 5, 5000 / 5) = 1000,
452 * which is optimal since a slice size of 999 bytes would already require
455 static int compute_slice_size(struct fec_client *fc, struct vss_task *vsst)
457 struct fec_group *g = &fc->group;
458 int k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
459 int n = fc->fcp->slices_per_group + fc->num_extra_slices;
460 int ret, k1, k2, h, d, min, max, sum;
461 int max_slice_bytes = fc->mps - FEC_HEADER_SIZE;
464 if (!need_audio_header(fc, vsst)) {
465 max_group_bytes = k * max_slice_bytes;
466 g->num_header_slices = 0;
467 compute_group_size(vsst, g, max_group_bytes);
468 g->slice_bytes = DIV_ROUND_UP(g->bytes, k);
469 if (g->slice_bytes == 0)
473 if (!need_data_slices(fc, vsst)) {
476 g->slice_bytes = DIV_ROUND_UP(vsst->header_len, k);
477 g->num_header_slices = k;
480 h = vsst->header_len;
481 max_group_bytes = (k - num_slices(h, max_slice_bytes, n - k))
483 compute_group_size(vsst, g, max_group_bytes);
486 g->slice_bytes = DIV_ROUND_UP(h, k);
487 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
490 g->num_header_slices = ret;
493 min = PARA_MIN(h, d);
494 max = PARA_MAX(h, d);
496 k1 = DIV_ROUND_UP(k * min, sum);
501 g->slice_bytes = PARA_MAX(DIV_ROUND_UP(min, k1), DIV_ROUND_UP(max, k2));
503 * This value of s := g->slice_bytes satisfies inequality (*) above,
504 * but it might be larger than max_slice_bytes. However, we know that
505 * max_slice_bytes are sufficient to store header and data, so:
507 g->slice_bytes = PARA_MIN((int)g->slice_bytes, max_slice_bytes);
509 ret = num_slices(vsst->header_len, g->slice_bytes, n - k);
512 g->num_header_slices = ret;
516 static int setup_next_fec_group(struct fec_client *fc, struct vss_task *vsst)
518 int ret, i, k, n, data_slices;
521 struct fec_group *g = &fc->group;
523 if (fc->state == FEC_STATE_NONE) {
524 ret = initialize_fec_client(fc, vsst);
527 g->first_chunk = mmd->current_chunk;
532 if (g->first_chunk + g->num_chunks >= mmd->afd.afhi.chunks_total)
535 * Start and duration of this group depend only on the previous
536 * group. Compute the new group start as g->start += g->duration.
539 tv_add(&tmp, &g->duration, &g->start);
540 set_group_timing(fc, vsst);
541 g->first_chunk += g->num_chunks;
544 k = fc->fcp->data_slices_per_group + fc->num_extra_slices;
545 n = fc->fcp->slices_per_group + fc->num_extra_slices;
547 compute_slice_size(fc, vsst);
548 assert(g->slice_bytes > 0);
549 ret = num_slices(g->bytes, g->slice_bytes, n - k);
553 assert(g->num_header_slices + data_slices <= k);
554 fc->current_slice_num = 0;
556 set_group_timing(fc, vsst);
557 /* setup header slices */
558 buf = vsst->header_buf;
559 for (i = 0; i < g->num_header_slices; i++) {
560 uint32_t payload_size;
561 if (buf + g->slice_bytes <= vsst->header_buf + vsst->header_len) {
562 fc->src_data[i] = (const unsigned char *)buf;
563 buf += g->slice_bytes;
567 * Can not use vss->header_buf for this slice as it
568 * goes beyond the buffer. This slice will not be fully
571 payload_size = vsst->header_buf + vsst->header_len - buf;
572 memcpy(fc->extra_header_buf, buf, payload_size);
573 if (payload_size < g->slice_bytes)
574 memset(fc->extra_header_buf + payload_size, 0,
575 g->slice_bytes - payload_size);
577 * There might be more than one header slice to fill although
578 * only the first one will be used. Set all header slices to
581 while (i < g->num_header_slices)
582 fc->src_data[i++] = fc->extra_header_buf;
583 break; /* we don't want i to be increased. */
587 * Setup data slices. Note that for ogg streams chunk 0 points to a
588 * buffer on the heap rather than to the mapped audio file.
590 vss_get_chunk(g->first_chunk, vsst, &buf, &len);
591 for (p = buf; i < g->num_header_slices + data_slices; i++) {
592 if (p + g->slice_bytes > buf + g->bytes) {
594 * We must make a copy for this slice since using p
595 * directly would exceed the buffer.
597 uint32_t payload_size = buf + g->bytes - p;
598 assert(payload_size + FEC_HEADER_SIZE <= fc->mps);
599 memcpy(fc->extra_src_buf, p, payload_size);
600 if (payload_size < g->slice_bytes)
601 memset(fc->extra_src_buf + payload_size, 0,
602 g->slice_bytes - payload_size);
603 fc->src_data[i] = fc->extra_src_buf;
607 fc->src_data[i] = (const unsigned char *)p;
611 /* use arbitrary data for all remaining slices */
614 fc->src_data[i] = (const unsigned char *)buf;
616 PARA_DEBUG_LOG("FEC group %u: %u chunks (%u - %u), %u bytes\n",
617 g->num, g->num_chunks, g->first_chunk,
618 g->first_chunk + g->num_chunks - 1, g->bytes
620 PARA_DEBUG_LOG("slice_bytes: %d, %d header slices, %d data slices\n",
621 g->slice_bytes, g->num_header_slices, data_slices
626 static int compute_next_fec_slice(struct fec_client *fc, struct vss_task *vsst)
628 if (fc->state == FEC_STATE_NONE || fc->current_slice_num
629 == fc->fcp->slices_per_group + fc->num_extra_slices) {
630 int ret = setup_next_fec_group(fc, vsst);
634 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
635 PARA_ERROR_LOG("FEC client temporarily disabled\n");
636 fc->state = FEC_STATE_DISABLED;
640 write_fec_header(fc, vsst);
641 fec_encode(fc->parms, fc->src_data, fc->enc_buf + FEC_HEADER_SIZE,
642 fc->current_slice_num, fc->group.slice_bytes);
647 * Return a buffer that marks the end of the stream.
649 * \param buf Result pointer.
650 * \return The length of the eof buffer.
652 * This is used for (multicast) udp streaming where closing the socket on the
653 * sender might not give rise to an eof condition at the peer.
655 size_t vss_get_fec_eof_packet(const char **buf)
657 static const char fec_eof_packet[FEC_HEADER_SIZE] = FEC_EOF_PACKET;
658 *buf = fec_eof_packet;
659 return FEC_HEADER_SIZE;
663 * Add one entry to the list of active fec clients.
665 * \param sc Generic sender_client data of the transport layer.
666 * \param fcp FEC parameters as supplied by the transport layer.
668 * \return Newly allocated fec_client struct.
670 struct fec_client *vss_add_fec_client(struct sender_client *sc,
671 struct fec_client_parms *fcp)
673 struct fec_client *fc = para_calloc(sizeof(*fc));
677 para_list_add(&fc->node, &fec_client_list);
682 * Remove one entry from the list of active fec clients.
684 * \param fc The client to be removed.
686 void vss_del_fec_client(struct fec_client *fc)
691 free(fc->extra_src_buf);
692 free(fc->extra_header_buf);
698 * Compute if/when next slice is due. If it isn't due yet and \a diff is
699 * not \p Null, compute the time difference next - now, where
701 * next = stream_start + (first_group_chunk - first_stream_chunk)
702 * * chunk_time + slice_num * slice_time
704 static int next_slice_is_due(struct fec_client *fc, struct timeval *diff)
706 struct timeval tmp, next;
709 if (fc->state == FEC_STATE_NONE)
711 tv_scale(fc->current_slice_num, &fc->group.slice_duration, &tmp);
712 tv_add(&tmp, &fc->group.start, &next);
713 ret = tv_diff(&next, now, diff);
714 return ret < 0? 1 : 0;
717 static void set_eof_barrier(struct vss_task *vsst)
719 struct fec_client *fc;
720 struct timeval timeout = {1, 0}, *chunk_tv = vss_chunk_time();
724 list_for_each_entry(fc, &fec_client_list, node) {
725 struct timeval group_duration;
727 if (fc->state != FEC_STATE_READY_TO_RUN)
729 tv_scale(fc->group.num_chunks, chunk_tv, &group_duration);
730 if (tv_diff(&timeout, &group_duration, NULL) < 0)
731 timeout = group_duration;
734 tv_add(now, &timeout, &vsst->eof_barrier);
738 * Check if vss status flag \a P (playing) is set.
740 * \return Greater than zero if playing, zero otherwise.
743 unsigned int vss_playing(void)
745 return mmd->new_vss_status_flags & VSS_PLAYING;
749 * Check if the \a N (next) status flag is set.
751 * \return Greater than zero if set, zero if not.
754 unsigned int vss_next(void)
756 return mmd->new_vss_status_flags & VSS_NEXT;
760 * Check if a reposition request is pending.
762 * \return Greater than zero if true, zero otherwise.
765 unsigned int vss_repos(void)
767 return mmd->new_vss_status_flags & VSS_REPOS;
771 * Check if the vss is currently paused.
773 * \return Greater than zero if paused, zero otherwise.
776 unsigned int vss_paused(void)
778 return !(mmd->new_vss_status_flags & VSS_NEXT)
779 && !(mmd->new_vss_status_flags & VSS_PLAYING);
783 * Check if the vss is currently stopped.
785 * \return Greater than zero if paused, zero otherwise.
788 unsigned int vss_stopped(void)
790 return (mmd->new_vss_status_flags & VSS_NEXT)
791 && !(mmd->new_vss_status_flags & VSS_PLAYING);
794 static int chk_barrier(const char *bname, const struct timeval *barrier,
795 struct timeval *diff, int print_log)
799 if (tv_diff(now, barrier, diff) > 0)
803 PARA_DEBUG_LOG("%s barrier: %lims left\n", bname, ms);
807 static void vss_compute_timeout(struct sched *s, struct vss_task *vsst)
810 struct fec_client *fc;
812 if (!vss_playing() || !vsst->map)
814 if (vss_next() && vsst->map) /* only sleep a bit, nec*/
815 return sched_request_timeout_ms(100, s);
817 /* Each of these barriers must have passed until we may proceed */
818 if (sched_request_barrier(&vsst->autoplay_barrier, s) == 1)
820 if (sched_request_barrier(&vsst->eof_barrier, s) == 1)
822 if (sched_request_barrier(&vsst->data_send_barrier, s) == 1)
825 * Compute the select timeout as the minimal time until the next
826 * chunk/slice is due for any client.
828 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
829 &mmd->stream_start, &tv);
830 if (sched_request_barrier_or_min_delay(&tv, s) == 0)
832 list_for_each_entry(fc, &fec_client_list, node) {
833 if (fc->state != FEC_STATE_READY_TO_RUN)
835 if (next_slice_is_due(fc, &tv))
836 return sched_min_delay(s);
837 sched_request_timeout(&tv, s);
841 static void vss_eof(struct vss_task *vsst)
846 if (mmd->new_vss_status_flags & VSS_NOMORE)
847 mmd->new_vss_status_flags = VSS_NEXT;
848 set_eof_barrier(vsst);
849 afh_free_header(vsst->header_buf, mmd->afd.audio_format_id);
850 vsst->header_buf = NULL;
851 para_munmap(vsst->map, vsst->mapsize);
853 mmd->chunks_sent = 0;
855 mmd->afd.afhi.seconds_total = 0;
856 mmd->afd.afhi.chunk_tv.tv_sec = 0;
857 mmd->afd.afhi.chunk_tv.tv_usec = 0;
858 free(mmd->afd.afhi.chunk_table);
859 mmd->afd.afhi.chunk_table = NULL;
864 static int need_to_request_new_audio_file(struct vss_task *vsst)
868 if (vsst->map) /* have audio file */
870 if (!vss_playing()) /* don't need one */
872 if (mmd->new_vss_status_flags & VSS_NOMORE)
874 if (vsst->afsss == AFS_SOCKET_AFD_PENDING) /* already requested one */
876 if (chk_barrier("autoplay_delay", &vsst->autoplay_barrier,
882 static void set_mmd_offset(void)
884 struct timeval offset;
885 tv_scale(mmd->current_chunk, &mmd->afd.afhi.chunk_tv, &offset);
886 mmd->offset = tv2ms(&offset);
889 static void vss_pre_select(struct sched *s, void *context)
892 struct vss_task *vsst = context;
894 if (need_to_request_new_audio_file(vsst)) {
895 PARA_DEBUG_LOG("ready and playing, but no audio file\n");
896 para_fd_set(vsst->afs_socket, &s->wfds, &s->max_fileno);
897 vsst->afsss = AFS_SOCKET_CHECK_FOR_WRITE;
899 para_fd_set(vsst->afs_socket, &s->rfds, &s->max_fileno);
900 for (i = 0; senders[i].name; i++) {
901 if (!senders[i].pre_select)
903 senders[i].pre_select(&s->max_fileno, &s->rfds, &s->wfds);
905 vss_compute_timeout(s, vsst);
908 static int recv_afs_msg(int afs_socket, int *fd, uint32_t *code, uint32_t *data)
910 char control[255] __a_aligned(8), buf[8];
911 struct msghdr msg = {.msg_iov = NULL};
912 struct cmsghdr *cmsg;
918 iov.iov_len = sizeof(buf);
921 msg.msg_control = control;
922 msg.msg_controllen = sizeof(control);
923 memset(buf, 0, sizeof(buf));
924 ret = recvmsg(afs_socket, &msg, 0);
926 return -ERRNO_TO_PARA_ERROR(errno);
927 if (iov.iov_len != sizeof(buf))
928 return -E_AFS_SHORT_READ;
929 *code = *(uint32_t*)buf;
930 *data = *(uint32_t*)(buf + 4);
931 for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
932 if (cmsg->cmsg_level != SOL_SOCKET
933 || cmsg->cmsg_type != SCM_RIGHTS)
935 if ((cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int) != 1)
937 *fd = *(int *)CMSG_DATA(cmsg);
943 #define MAP_POPULATE 0
946 static void recv_afs_result(struct vss_task *vsst, fd_set *rfds)
948 int ret, passed_fd, shmid;
949 uint32_t afs_code = 0, afs_data = 0;
952 if (!FD_ISSET(vsst->afs_socket, rfds))
954 ret = recv_afs_msg(vsst->afs_socket, &passed_fd, &afs_code, &afs_data);
955 if (ret == -ERRNO_TO_PARA_ERROR(EAGAIN))
959 vsst->afsss = AFS_SOCKET_READY;
960 PARA_DEBUG_LOG("fd: %d, code: %u, shmid: %u\n", passed_fd, afs_code,
963 if (afs_code != NEXT_AUDIO_FILE)
968 ret = load_afd(shmid, &mmd->afd);
972 ret = fstat(passed_fd, &statbuf);
974 PARA_ERROR_LOG("fstat error:\n");
975 ret = -ERRNO_TO_PARA_ERROR(errno);
978 ret = para_mmap(statbuf.st_size, PROT_READ, MAP_PRIVATE | MAP_POPULATE,
979 passed_fd, 0, &vsst->map);
982 vsst->mapsize = statbuf.st_size;
984 mmd->chunks_sent = 0;
985 mmd->current_chunk = 0;
989 mmd->new_vss_status_flags &= (~VSS_NEXT);
990 afh_get_header(&mmd->afd.afhi, mmd->afd.audio_format_id,
991 vsst->map, vsst->mapsize, &vsst->header_buf, &vsst->header_len);
994 free(mmd->afd.afhi.chunk_table);
997 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
998 mmd->new_vss_status_flags = VSS_NEXT;
1002 * Main sending function.
1004 * This function gets called from vss_post_select(). It checks whether the next
1005 * chunk of data should be pushed out. It obtains a pointer to the data to be
1006 * sent out as well as its length from mmd->afd.afhi. This information is then
1007 * passed to each supported sender's send() function as well as to the send()
1008 * functions of each registered fec client.
1010 static void vss_send(struct vss_task *vsst)
1012 int i, fec_active = 0;
1014 struct fec_client *fc, *tmp_fc;
1016 if (!vsst->map || !vss_playing())
1018 if (chk_barrier("eof", &vsst->eof_barrier, &due, 1) < 0)
1020 if (chk_barrier("data send", &vsst->data_send_barrier,
1023 list_for_each_entry_safe(fc, tmp_fc, &fec_client_list, node) {
1024 if (fc->state == FEC_STATE_DISABLED)
1026 if (!next_slice_is_due(fc, NULL)) {
1030 if (compute_next_fec_slice(fc, vsst) <= 0)
1032 PARA_DEBUG_LOG("sending %u:%u (%u bytes)\n", fc->group.num,
1033 fc->current_slice_num, fc->group.slice_bytes);
1034 fc->fcp->send_fec(fc->sc, (char *)fc->enc_buf,
1035 fc->group.slice_bytes + FEC_HEADER_SIZE);
1036 fc->current_slice_num++;
1039 if (mmd->current_chunk >= mmd->afd.afhi.chunks_total) { /* eof */
1041 mmd->new_vss_status_flags |= VSS_NEXT;
1044 compute_chunk_time(mmd->chunks_sent, &mmd->afd.afhi.chunk_tv,
1045 &mmd->stream_start, &due);
1046 if (tv_diff(&due, now, NULL) <= 0) {
1050 if (!mmd->chunks_sent) {
1051 mmd->stream_start = *now;
1056 * We call the send function also in case of empty chunks as
1057 * they might have still some data queued which can be sent in
1060 vss_get_chunk(mmd->current_chunk, vsst, &buf, &len);
1061 for (i = 0; senders[i].name; i++) {
1062 if (!senders[i].send)
1064 senders[i].send(mmd->current_chunk, mmd->chunks_sent,
1065 buf, len, vsst->header_buf, vsst->header_len);
1068 * Prefault next chunk(s)
1070 * If the backing device of the memory-mapped audio file is
1071 * slow and read-ahead is turned off or prevented for some
1072 * reason, e.g. due to memory pressure, it may take much longer
1073 * than the chunk interval to get the next chunk on the wire,
1074 * causing buffer underruns on the client side. Mapping the
1075 * file with MAP_POPULATE seems to help a bit, but it does not
1076 * eliminate the delays completely. Moreover, it is supported
1077 * only on Linux. So we do our own read-ahead here.
1079 if (mmd->current_chunk > 0) { /* chunk 0 might be on the heap */
1081 for (i = 0; i < 5 && buf < vsst->map + vsst->mapsize; i++) {
1082 __a_unused volatile char x = *buf;
1087 mmd->current_chunk++;
1091 static int vss_post_select(struct sched *s, void *context)
1094 struct vss_task *vsst = context;
1096 if (!vsst->map || vss_next() || vss_paused() || vss_repos()) {
1097 /* shut down senders and fec clients */
1098 struct fec_client *fc, *tmp;
1099 for (i = 0; senders[i].name; i++)
1100 if (senders[i].shutdown_clients)
1101 senders[i].shutdown_clients();
1102 list_for_each_entry_safe(fc, tmp, &fec_client_list, node)
1103 fc->state = FEC_STATE_NONE;
1104 mmd->stream_start.tv_sec = 0;
1105 mmd->stream_start.tv_usec = 0;
1109 else if (vss_paused()) {
1110 if (mmd->chunks_sent)
1111 set_eof_barrier(vsst);
1112 mmd->chunks_sent = 0;
1113 } else if (vss_repos()) { /* repositioning due to ff/jmp command */
1114 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
1115 set_eof_barrier(vsst);
1116 mmd->chunks_sent = 0;
1117 mmd->current_chunk = afh_get_start_chunk(mmd->repos_request,
1119 mmd->new_vss_status_flags &= ~VSS_REPOS;
1122 /* If a sender command is pending, run it. */
1123 if (mmd->sender_cmd_data.cmd_num >= 0) {
1124 int num = mmd->sender_cmd_data.cmd_num,
1125 sender_num = mmd->sender_cmd_data.sender_num;
1127 if (senders[sender_num].client_cmds[num]) {
1128 ret = senders[sender_num].client_cmds[num]
1129 (&mmd->sender_cmd_data);
1131 PARA_ERROR_LOG("%s\n", para_strerror(-ret));
1133 mmd->sender_cmd_data.cmd_num = -1;
1135 if (vsst->afsss != AFS_SOCKET_CHECK_FOR_WRITE)
1136 recv_afs_result(vsst, &s->rfds);
1137 else if (FD_ISSET(vsst->afs_socket, &s->wfds)) {
1138 PARA_NOTICE_LOG("requesting new fd from afs\n");
1139 ret = write_buffer(vsst->afs_socket, "new");
1141 PARA_CRIT_LOG("%s\n", para_strerror(-ret));
1143 vsst->afsss = AFS_SOCKET_AFD_PENDING;
1145 for (i = 0; senders[i].name; i++) {
1146 if (!senders[i].post_select)
1148 senders[i].post_select(&s->rfds, &s->wfds);
1150 if ((vss_playing() && !(mmd->vss_status_flags & VSS_PLAYING)) ||
1151 (vss_next() && vss_playing()))
1152 tv_add(now, &vsst->announce_tv, &vsst->data_send_barrier);
1158 * Initialize the virtual streaming system task.
1160 * \param afs_socket The fd for communication with afs.
1161 * \param s The scheduler to register the vss task to.
1163 * This also initializes all supported senders and starts streaming
1164 * if the --autoplay command line flag was given.
1166 void init_vss_task(int afs_socket, struct sched *s)
1168 static struct vss_task vss_task_struct, *vsst = &vss_task_struct;
1170 char *hn = para_hostname(), *home = para_homedir();
1171 long unsigned announce_time = conf.announce_time_arg > 0?
1172 conf.announce_time_arg : 300,
1173 autoplay_delay = conf.autoplay_delay_arg > 0?
1174 conf.autoplay_delay_arg : 0;
1175 vsst->header_interval.tv_sec = 5; /* should this be configurable? */
1176 vsst->afs_socket = afs_socket;
1177 ms2tv(announce_time, &vsst->announce_tv);
1178 PARA_INFO_LOG("announce timeval: %lums\n", tv2ms(&vsst->announce_tv));
1179 INIT_LIST_HEAD(&fec_client_list);
1180 for (i = 0; senders[i].name; i++) {
1181 PARA_NOTICE_LOG("initializing %s sender\n", senders[i].name);
1182 senders[i].init(&senders[i]);
1186 mmd->sender_cmd_data.cmd_num = -1;
1187 if (conf.autoplay_given) {
1189 mmd->vss_status_flags |= VSS_PLAYING;
1190 mmd->new_vss_status_flags |= VSS_PLAYING;
1191 ms2tv(autoplay_delay, &tmp);
1192 tv_add(clock_get_realtime(NULL), &tmp, &vsst->autoplay_barrier);
1193 tv_add(&vsst->autoplay_barrier, &vsst->announce_tv,
1194 &vsst->data_send_barrier);
1196 vsst->task = task_register(&(struct task_info) {
1198 .pre_select = vss_pre_select,
1199 .post_select = vss_post_select,