* systems. There is no support for Microsoft Windows yet, and that will in
* fact probably an entirely separate program.
*
- * The program runs (at least) three threads. listen_thread() is responsible
- * for reading RTP packets off the wire and adding them to the linked list @ref
- * received_packets, assuming they are basically sound. queue_thread() takes
- * packets off this linked list and adds them to @ref packets (an operation
- * which might be much slower due to contention for @ref lock).
+ * The program runs (at least) three threads:
*
- * The main thread is responsible for actually playing audio. In ALSA this
- * means it waits until ALSA says it's ready for more audio which it then
- * plays. See @ref clients/playrtp-alsa.c.
+ * listen_thread() is responsible for reading RTP packets off the wire and
+ * adding them to the linked list @ref received_packets, assuming they are
+ * basically sound.
*
- * In Core Audio the main thread is only responsible for starting and stopping
- * play: the system does the actual playback in its own private thread, and
- * calls adioproc() to fetch the audio data. See @ref
- * clients/playrtp-coreaudio.c.
+ * queue_thread() takes packets off this linked list and adds them to @ref
+ * packets (an operation which might be much slower due to contention for @ref
+ * lock).
+ *
+ * control_thread() accepts commands from Disobedience (or anything else).
+ *
+ * The main thread activates and deactivates audio playing via the @ref
+ * lib/uaudio.h API (which probably implies at least one further thread).
*
* Sometimes it happens that there is no audio available to play. This may
* because the server went away, or a packet was dropped, or the server
#include <unistd.h>
#include <sys/mman.h>
#include <fcntl.h>
+#include <math.h>
#include "log.h"
#include "mem.h"
#include "version.h"
#include "uaudio.h"
-#define readahead linux_headers_are_borked
-
/** @brief Obsolete synonym */
#ifndef IPV6_JOIN_GROUP
# define IPV6_JOIN_GROUP IPV6_ADD_MEMBERSHIP
/** @brief Output device */
-/** @brief Minimum low watermark
- *
- * We'll stop playing if there's only this many samples in the buffer. */
-unsigned minbuffer = 2 * 44100 / 10; /* 0.2 seconds */
-
-/** @brief Buffer high watermark
- *
- * We'll only start playing when this many samples are available. */
-static unsigned readahead = 2 * 2 * 44100;
+/** @brief Buffer low watermark in samples */
+unsigned minbuffer = 4 * (2 * 44100) / 10; /* 0.4 seconds */
-/** @brief Maximum buffer size
+/** @brief Maximum buffer size in samples
*
- * We'll stop reading from the network if we have this many samples. */
+ * We'll stop reading from the network if we have this many samples.
+ */
static unsigned maxbuffer;
/** @brief Received packets
{ "device", required_argument, 0, 'D' },
{ "min", required_argument, 0, 'm' },
{ "max", required_argument, 0, 'x' },
- { "buffer", required_argument, 0, 'b' },
{ "rcvbuf", required_argument, 0, 'R' },
#if HAVE_SYS_SOUNDCARD_H || EMPEG_HOST
{ "oss", no_argument, 0, 'o' },
{ "core-audio", no_argument, 0, 'c' },
#endif
{ "dump", required_argument, 0, 'r' },
+ { "command", required_argument, 0, 'e' },
+ { "pause-mode", required_argument, 0, 'P' },
{ "socket", required_argument, 0, 's' },
{ "config", required_argument, 0, 'C' },
+ { "monitor", no_argument, 0, 'M' },
{ 0, 0, 0, 0 }
};
pthread_cond_broadcast(&cond);
pthread_mutex_unlock(&lock);
}
+#if HAVE_STUPID_GCC44
+ return NULL;
+#endif
}
/** @brief Background thread collecting samples
fatal(0, "unsupported RTP payload type %d",
header.mpt & 0x7F);
}
+ /* See if packet is silent */
+ const uint16_t *s = p->samples_raw;
+ n = p->nsamples;
+ for(; n > 0; --n)
+ if(*s++)
+ break;
+ if(!n)
+ p->flags |= SILENT;
if(logfp)
fprintf(logfp, "sequence %u timestamp %"PRIx32" length %"PRIx32" end %"PRIx32"\n",
seq, timestamp, p->nsamples, timestamp + p->nsamples);
* Must be called with @ref lock held.
*/
void playrtp_fill_buffer(void) {
- while(nsamples)
+ /* Discard current buffer contents */
+ while(nsamples) {
+ //fprintf(stderr, "%8u/%u (%u) DROPPING\n", nsamples, maxbuffer, minbuffer);
drop_first_packet();
+ }
info("Buffering...");
- while(nsamples < readahead) {
+ /* Wait until there's at least minbuffer samples available */
+ while(nsamples < minbuffer) {
+ //fprintf(stderr, "%8u/%u (%u) FILLING\n", nsamples, maxbuffer, minbuffer);
pthread_cond_wait(&cond, &lock);
}
+ /* Start from whatever is earliest */
next_timestamp = pheap_first(&packets)->timestamp;
active = 1;
}
/* display usage message and terminate */
static void help(void) {
xprintf("Usage:\n"
- " disorder-playrtp [OPTIONS] ADDRESS [PORT]\n"
+ " disorder-playrtp [OPTIONS] [[ADDRESS] PORT]\n"
"Options:\n"
" --device, -D DEVICE Output device\n"
" --min, -m FRAMES Buffer low water mark\n"
- " --buffer, -b FRAMES Buffer high water mark\n"
" --max, -x FRAMES Buffer maximum size\n"
" --rcvbuf, -R BYTES Socket receive buffer size\n"
" --config, -C PATH Set configuration file\n"
#if HAVE_COREAUDIO_AUDIOHARDWARE_H
" --core-audio, -c Use Core Audio to play audio\n"
#endif
+ " --command, -e COMMAND Pipe audio to command.\n"
+ " --pause-mode, -P silence For -e: pauses send silence (default)\n"
+ " --pause-mode, -P suspend For -e: pauses suspend writes\n"
" --help, -h Display usage message\n"
" --version, -V Display version number\n"
);
size_t max_samples,
void attribute((unused)) *userdata) {
size_t samples;
+ int silent = 0;
pthread_mutex_lock(&lock);
/* Get the next packet, junking any that are now in the past */
*bufptr++ = (int16_t)ntohs(*ptr++);
--i;
}
- /* We don't junk the packet here; a subsequent call to
- * playrtp_next_packet() will dispose of it (if it's actually done with). */
+ silent = !!(p->flags & SILENT);
} else {
/* There is no suitable packet. We introduce 0s up to the next packet, or
* to fill the buffer if there's no next packet or that's too many. The
samples = max_samples;
//info("infill by %zu", samples);
memset(buffer, 0, samples * uaudio_sample_size);
+ silent = 1;
}
/* Debug dump */
if(dump_buffer) {
}
/* Advance timestamp */
next_timestamp += samples;
+ /* If we're getting behind then try to drop just silent packets
+ *
+ * In theory this shouldn't be necessary. The server is supposed to send
+ * packets at the right rate and compares the number of samples sent with the
+ * time in order to ensure this.
+ *
+ * However, various things could throw this off:
+ *
+ * - the server's clock could advance at the wrong rate. This would cause it
+ * to mis-estimate the right number of samples to have sent and
+ * inappropriately throttle or speed up.
+ *
+ * - playback could happen at the wrong rate. If the playback host's sound
+ * card has a slightly incorrect clock then eventually it will get out
+ * of step.
+ *
+ * So if we play back slightly slower than the server sends for either of
+ * these reasons then eventually our buffer, and the socket's buffer, will
+ * fill, and the kernel will start dropping packets. The result is audible
+ * and not very nice.
+ *
+ * Therefore if we're getting behind, we pre-emptively drop silent packets,
+ * since a change in the duration of a silence is less noticeable than a
+ * dropped packet from the middle of continuous music.
+ *
+ * (If things go wrong the other way then eventually we run out of packets to
+ * play and are forced to play silence. This doesn't seem to happen in
+ * practice but if it does then in the same way we can artificially extend
+ * silent packets to compensate.)
+ *
+ * Dropped packets are always logged; use 'disorder-playrtp --monitor' to
+ * track how close to target buffer occupancy we are on a once-a-minute
+ * basis.
+ */
+ if(nsamples > minbuffer && silent) {
+ info("dropping %zu samples (%"PRIu32" > %"PRIu32")",
+ samples, nsamples, minbuffer);
+ samples = 0;
+ }
+ /* Junk obsolete packets */
+ playrtp_next_packet();
pthread_mutex_unlock(&lock);
return samples;
}
struct addrinfo *res;
struct stringlist sl;
char *sockname;
- int rcvbuf, target_rcvbuf = 131072;
+ int rcvbuf, target_rcvbuf = 0;
socklen_t len;
struct ip_mreq mreq;
struct ipv6_mreq mreq6;
};
union any_sockaddr mgroup;
const char *dumpfile = 0;
- const char *device = 0;
pthread_t ltid;
+ int monitor = 0;
+ static const int one = 1;
static const struct addrinfo prefs = {
.ai_flags = AI_PASSIVE,
.ai_protocol = IPPROTO_UDP
};
+ /* Timing information is often important to debugging playrtp, so we include
+ * timestamps in the logs */
+ logdate = 1;
mem_init();
if(!setlocale(LC_CTYPE, "")) fatal(errno, "error calling setlocale");
backend = uaudio_apis[0];
- while((n = getopt_long(argc, argv, "hVdD:m:b:x:L:R:M:aocC:r", options, 0)) >= 0) {
+ while((n = getopt_long(argc, argv, "hVdD:m:x:L:R:aocC:re:P:M", options, 0)) >= 0) {
switch(n) {
case 'h': help();
case 'V': version("disorder-playrtp");
case 'd': debugging = 1; break;
- case 'D': device = optarg; break;
+ case 'D': uaudio_set("device", optarg); break;
case 'm': minbuffer = 2 * atol(optarg); break;
- case 'b': readahead = 2 * atol(optarg); break;
case 'x': maxbuffer = 2 * atol(optarg); break;
case 'L': logfp = fopen(optarg, "w"); break;
case 'R': target_rcvbuf = atoi(optarg); break;
case 'C': configfile = optarg; break;
case 's': control_socket = optarg; break;
case 'r': dumpfile = optarg; break;
+ case 'e': backend = &uaudio_command; uaudio_set("command", optarg); break;
+ case 'P': uaudio_set("pause-mode", optarg); break;
+ case 'M': monitor = 1; break;
default: fatal(0, "invalid option");
}
}
- if(config_read(0)) fatal(0, "cannot read configuration");
+ if(config_read(0, NULL)) fatal(0, "cannot read configuration");
if(!maxbuffer)
- maxbuffer = 4 * readahead;
+ maxbuffer = 2 * minbuffer;
argc -= optind;
argv += optind;
switch(argc) {
res->ai_socktype,
res->ai_protocol)) < 0)
fatal(errno, "error creating socket");
- /* Stash the multicast group address */
- if((is_multicast = multicast(res->ai_addr))) {
+ /* Allow multiple listeners */
+ xsetsockopt(rtpfd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof one);
+ is_multicast = multicast(res->ai_addr);
+ /* The multicast and unicast/broadcast cases are different enough that they
+ * are totally split. Trying to find commonality between them causes more
+ * trouble that it's worth. */
+ if(is_multicast) {
+ /* Stash the multicast group address */
memcpy(&mgroup, res->ai_addr, res->ai_addrlen);
switch(res->ai_addr->sa_family) {
case AF_INET:
case AF_INET6:
mgroup.in6.sin6_port = 0;
break;
+ default:
+ fatal(0, "unsupported family %d", (int)res->ai_addr->sa_family);
}
- }
- /* Bind to 0/port */
- switch(res->ai_addr->sa_family) {
- case AF_INET:
- memset(&((struct sockaddr_in *)res->ai_addr)->sin_addr, 0,
- sizeof (struct in_addr));
- break;
- case AF_INET6:
- memset(&((struct sockaddr_in6 *)res->ai_addr)->sin6_addr, 0,
- sizeof (struct in6_addr));
- break;
- default:
- fatal(0, "unsupported family %d", (int)res->ai_addr->sa_family);
- }
- if(bind(rtpfd, res->ai_addr, res->ai_addrlen) < 0)
- fatal(errno, "error binding socket to %s", sockname);
- if(is_multicast) {
+ /* Bind to to the multicast group address */
+ if(bind(rtpfd, res->ai_addr, res->ai_addrlen) < 0)
+ fatal(errno, "error binding socket to %s", format_sockaddr(res->ai_addr));
+ /* Add multicast group membership */
switch(mgroup.sa.sa_family) {
case PF_INET:
mreq.imr_multiaddr = mgroup.in.sin_addr;
default:
fatal(0, "unsupported address family %d", res->ai_family);
}
+ /* Report what we did */
info("listening on %s multicast group %s",
format_sockaddr(res->ai_addr), format_sockaddr(&mgroup.sa));
- } else
+ } else {
+ /* Bind to 0/port */
+ switch(res->ai_addr->sa_family) {
+ case AF_INET: {
+ struct sockaddr_in *in = (struct sockaddr_in *)res->ai_addr;
+
+ memset(&in->sin_addr, 0, sizeof (struct in_addr));
+ break;
+ }
+ case AF_INET6: {
+ struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)res->ai_addr;
+
+ memset(&in6->sin6_addr, 0, sizeof (struct in6_addr));
+ break;
+ }
+ default:
+ fatal(0, "unsupported family %d", (int)res->ai_addr->sa_family);
+ }
+ if(bind(rtpfd, res->ai_addr, res->ai_addrlen) < 0)
+ fatal(errno, "error binding socket to %s", format_sockaddr(res->ai_addr));
+ /* Report what we did */
info("listening on %s", format_sockaddr(res->ai_addr));
+ }
len = sizeof rcvbuf;
if(getsockopt(rtpfd, SOL_SOCKET, SO_RCVBUF, &rcvbuf, &len) < 0)
fatal(errno, "error calling getsockopt SO_RCVBUF");
rcvbuf, target_rcvbuf);
} else
info("default socket receive buffer %d", rcvbuf);
+ //info("minbuffer %u maxbuffer %u", minbuffer, maxbuffer);
if(logfp)
info("WARNING: -L option can impact performance");
if(control_socket) {
fatal(errno, "mapping %s", dumpfile);
info("dumping to %s", dumpfile);
}
- /* Choose output device */
- if(device)
- uaudio_set("device", device);
/* Set up output. Currently we only support L16 so there's no harm setting
* the format before we know what it is! */
uaudio_set_format(44100/*Hz*/, 2/*channels*/,
if((err = pthread_create(<id, 0, queue_thread, 0)))
fatal(err, "pthread_create queue_thread");
pthread_mutex_lock(&lock);
+ time_t lastlog = 0;
for(;;) {
/* Wait for the buffer to fill up a bit */
playrtp_fill_buffer();
info("Playing...");
next_timestamp = pheap_first(&packets)->timestamp;
active = 1;
+ pthread_mutex_unlock(&lock);
backend->activate();
- /* Wait until the buffer empties out */
+ pthread_mutex_lock(&lock);
+ /* Wait until the buffer empties out
+ *
+ * If there's a packet that we can play right now then we definitely
+ * continue.
+ *
+ * Also if there's at least minbuffer samples we carry on regardless and
+ * insert silence. The assumption is there's been a pause but more data
+ * is now available.
+ */
while(nsamples >= minbuffer
|| (nsamples > 0
&& contains(pheap_first(&packets), next_timestamp))) {
+ if(monitor) {
+ time_t now = time(0);
+
+ if(now >= lastlog + 60) {
+ int offset = nsamples - minbuffer;
+ double offtime = (double)offset / (uaudio_rate * uaudio_channels);
+ info("%+d samples off (%d.%02ds, %d bytes)",
+ offset,
+ (int)fabs(offtime) * (offtime < 0 ? -1 : 1),
+ (int)(fabs(offtime) * 100) % 100,
+ offset * uaudio_bits / CHAR_BIT);
+ lastlog = now;
+ }
+ }
+ //fprintf(stderr, "%8u/%u (%u) PLAYING\n", nsamples, maxbuffer, minbuffer);
pthread_cond_wait(&cond, &lock);
}
+#if 0
+ if(nsamples) {
+ struct packet *p = pheap_first(&packets);
+ fprintf(stderr, "nsamples=%u (%u) next_timestamp=%"PRIx32", first packet is [%"PRIx32",%"PRIx32")\n",
+ nsamples, minbuffer, next_timestamp,p->timestamp,p->timestamp+p->nsamples);
+ }
+#endif
/* Stop playing for a bit until the buffer re-fills */
+ pthread_mutex_unlock(&lock);
backend->deactivate();
+ pthread_mutex_lock(&lock);
active = 0;
/* Go back round */
}