*/
#define MAXSAMPLES 2048
-/** @brief Minimum buffer size
+/** @brief Minimum low watermark
*
* We'll stop playing if there's only this many samples in the buffer. */
static unsigned minbuffer = 2 * 44100 / 10; /* 0.2 seconds */
* The maximum supported size (in bytes) of one sample. */
#define MAXSAMPLESIZE 2
-/** @brief Buffer size
+/** @brief Buffer high watermark
*
* We'll only start playing when this many samples are available. */
-static unsigned readahead = 4 * 2 * 44100; /* 4 seconds */
+static unsigned readahead = 2 * 2 * 44100;
-#define MAXBUFFER (3 * 88200) /* maximum buffer contents */
+/** @brief Maximum buffer size
+ *
+ * We'll stop reading from the network if we have this many samples. */
+static unsigned maxbuffer;
+
+/** @brief Number of samples to infill by in one go */
+#define INFILL_SAMPLES (44100 * 2) /* 1s */
/** @brief Received packet
*
* or mis-ordered there may be gaps at any given moment. */
struct packet *next;
/** @brief Number of samples in this packet */
- int nsamples;
- /** @brief Number of samples used from this packet */
- int nused;
+ uint32_t nsamples;
/** @brief Timestamp from RTP packet
*
* NB that "timestamps" are really sample counters.*/
/** @brief Linked list of packets
*
- * In ascending order of timestamp. */
+ * In ascending order of timestamp. Really this should be a heap for more
+ * efficient access. */
static struct packet *packets;
/** @brief Timestamp of next packet to play.
{ "debug", no_argument, 0, 'd' },
{ "device", required_argument, 0, 'D' },
{ "min", required_argument, 0, 'm' },
+ { "max", required_argument, 0, 'x' },
{ "buffer", required_argument, 0, 'b' },
{ 0, 0, 0, 0 }
};
return (uint32_t)(a - b) & 0x80000000;
}
+/** @brief Return true iff a >= b in sequence-space arithmetic */
+static inline int ge(uint32_t a, uint32_t b) {
+ return !lt(a, b);
+}
+
+/** @brief Return true iff a > b in sequence-space arithmetic */
+static inline int gt(uint32_t a, uint32_t b) {
+ return lt(b, a);
+}
+
+/** @brief Return true iff a <= b in sequence-space arithmetic */
+static inline int le(uint32_t a, uint32_t b) {
+ return !lt(b, a);
+}
+
+/** @brief Drop the packet at the head of the queue */
+static void drop_first_packet(void) {
+ struct packet *const p = packets;
+ packets = p->next;
+ nsamples -= p->nsamples;
+ free(p);
+ pthread_cond_broadcast(&cond);
+}
+
/** @brief Background thread collecting samples
*
* This function collects samples, perhaps converts them to the target format,
/* Ignore too-short packets */
if((size_t)n <= sizeof (struct rtp_header))
continue;
- p->nused = 0;
p->timestamp = ntohl(packet.header.timestamp);
/* Ignore packets in the past */
- if(active && lt(p->timestamp, next_timestamp))
+ if(active && lt(p->timestamp, next_timestamp)) {
+ info("dropping old packet, timestamp=%"PRIx32" < %"PRIx32,
+ p->timestamp, next_timestamp);
continue;
+ }
/* Convert to target format */
switch(packet.header.mpt & 0x7F) {
case 10:
p->nsamples = (n - sizeof (struct rtp_header)) / sizeof(uint16_t);
#if HAVE_COREAUDIO_AUDIOHARDWARE_H
/* Convert to what Core Audio expects */
- for(n = 0; n < p->nsamples; ++n)
- p->samples_float[n] = (int16_t)ntohs(samples[n]) * (0.5f / 32767);
+ {
+ size_t i;
+
+ for(i = 0; i < p->nsamples; ++n)
+ p->samples_float[i] = (int16_t)ntohs(samples[i]) * (0.5f / 32767);
+ }
#else
/* ALSA can do any necessary conversion itself (though it might be better
* to do any necessary conversion in the background) */
*
* This is rather unsatisfactory: it means that if packets get heavily
* out of order then we guarantee dropouts. But for now... */
- while(nsamples >= MAXBUFFER)
+ while(nsamples >= maxbuffer)
pthread_cond_wait(&cond, &lock);
for(pp = &packets;
*pp && lt((*pp)->timestamp, p->timestamp);
if(*pp && p->timestamp == (*pp)->timestamp) {
/* *pp == p; a duplicate. Ideally we avoid the translation step here,
* but we'll worry about that another time. */
+ info("dropped a duplicated");
} else {
+ if(*pp)
+ info("receiving packets out of order");
p->next = *pp;
*pp = p;
nsamples += p->nsamples;
#if HAVE_COREAUDIO_AUDIOHARDWARE_H
/** @brief Callback from Core Audio */
-static OSStatus adioproc(AudioDeviceID inDevice,
- const AudioTimeStamp *inNow,
- const AudioBufferList *inInputData,
- const AudioTimeStamp *inInputTime,
- AudioBufferList *outOutputData,
- const AudioTimeStamp *inOutputTime,
- void *inClientData) {
+static OSStatus adioproc
+ (AudioDeviceID attribute((unused)) inDevice,
+ const AudioTimeStamp attribute((unused)) *inNow,
+ const AudioBufferList attribute((unused)) *inInputData,
+ const AudioTimeStamp attribute((unused)) *inInputTime,
+ AudioBufferList *outOutputData,
+ const AudioTimeStamp attribute((unused)) *inOutputTime,
+ void attribute((unused)) *inClientData) {
UInt32 nbuffers = outOutputData->mNumberBuffers;
AudioBuffer *ab = outOutputData->mBuffers;
- float *samplesOut; /* where to write samples to */
- size_t samplesOutLeft; /* space left */
- size_t samplesInLeft;
- size_t samplesToCopy;
pthread_mutex_lock(&lock);
- samplesOut = ab->data;
- samplesOutLeft = ab->mDataByteSize / sizeof (float);
- while(packets && nbuffers > 0) {
- if(packets->used == packets->nsamples) {
- /* TODO if we dropped a packet then we should introduce a gap here */
- struct packet *const p = packets;
- packets = p->next;
- free(p);
- pthread_cond_broadcast(&cond);
- continue;
- }
- if(samplesOutLeft == 0) {
- --nbuffers;
- ++ab;
- samplesOut = ab->data;
- samplesOutLeft = ab->mDataByteSize / sizeof (float);
- continue;
+ while(nbuffers > 0) {
+ float *samplesOut = ab->mData;
+ size_t samplesOutLeft = ab->mDataByteSize / sizeof (float);
+
+ while(samplesOutLeft > 0) {
+ if(packets) {
+ /* There's a packet */
+ const uint32_t packet_start = packets->timestamp;
+ const uint32_t packet_end = packets->timestamp + packets->nsamples;
+
+ if(le(packet_end, next_timestamp)) {
+ /* This packet is in the past */
+ info("dropping buffered past packet %"PRIx32" < %"PRIx32,
+ packets->timestamp, next_timestamp);
+ continue;
+ }
+ if(ge(next_timestamp, packet_start)
+ && lt(next_timestamp, packet_end)) {
+ /* This packet is suitable */
+ const uint32_t offset = next_timestamp - packets->timestamp;
+ uint32_t samples_available = packet_end - next_timestamp;
+ if(samples_available > samplesOutLeft)
+ samples_available = samplesOutLeft;
+ memcpy(samplesOut,
+ packets->samples_float + offset,
+ samples_available * sizeof(float));
+ samplesOut += samples_available;
+ next_timestamp += samples_available;
+ if(ge(next_timestamp, packet_end))
+ drop_first_packet();
+ continue;
+ }
+ }
+ /* We didn't find a suitable packet (though there might still be
+ * unsuitable ones). We infill with 0s. */
+ if(packets) {
+ /* There is a next packet, only infill up to that point */
+ uint32_t samples_available = packets->timestamp - next_timestamp;
+
+ if(samples_available > samplesOutLeft)
+ samples_available = samplesOutLeft;
+ /* Convniently the buffer is 0 to start with */
+ next_timestamp += samples_available;
+ samplesOut += samples_available;
+ samplesOutLeft -= samples_available;
+ /* TODO log infill */
+ } else {
+ /* There's no next packet at all */
+ next_timestamp += samplesOutLeft;
+ samplesOut += samplesOutLeft;
+ samplesOutLeft = 0;
+ /* TODO log infill */
+ }
}
- /* Now: (1) there is some data left to read
- * (2) there is some space to put it */
- samplesInLeft = packets->nsamples - packets->used;
- samplesToCopy = (samplesInLeft < samplesOutLeft
- ? samplesInLeft : samplesOutLeft);
- memcpy(samplesOut, packet->samples + packets->used, samplesToCopy);
- packets->used += samplesToCopy;
- samplesOut += samplesToCopy;
- samesOutLeft -= samplesToCopy;
+ ++ab;
+ --nbuffers;
}
pthread_mutex_unlock(&lock);
return 0;
size_t samples_written;
int prepared = 1;
int err;
- int infilling = 0;
+ int infilling = 0, escape = 0;
+ time_t logged, now;
+ uint32_t packet_start, packet_end;
/* Open ALSA */
if((err = snd_pcm_open(&pcm,
/* Ready to go */
+ time(&logged);
pthread_mutex_lock(&lock);
for(;;) {
/* Wait for the buffer to fill up a bit */
+ logged = now;
+ info("%lu samples in buffer (%lus)", nsamples,
+ nsamples / (44100 * 2));
info("Buffering...");
while(nsamples < readahead)
pthread_cond_wait(&cond, &lock);
next_timestamp = packets->timestamp;
active = 1;
infilling = 0;
+ escape = 0;
+ logged = now;
+ info("%lu samples in buffer (%lus)", nsamples,
+ nsamples / (44100 * 2));
info("Playing...");
/* Wait until the buffer empties out */
- while(nsamples >= minbuffer) {
+ while(nsamples >= minbuffer && !escape) {
+ time(&now);
+ if(now > logged + 10) {
+ logged = now;
+ info("%lu samples in buffer (%lus)", nsamples,
+ nsamples / (44100 * 2));
+ }
+ if(packets
+ && ge(next_timestamp, packets->timestamp + packets->nsamples)) {
+ info("dropping buffered past packet %"PRIx32" < %"PRIx32,
+ packets->timestamp, next_timestamp);
+ drop_first_packet();
+ continue;
+ }
/* Wait for ALSA to ask us for more data */
pthread_mutex_unlock(&lock);
- snd_pcm_wait(pcm, -1);
+ write(2, ".", 1); /* TODO remove me sometime */
+ switch(err = snd_pcm_wait(pcm, -1)) {
+ case 0:
+ info("snd_pcm_wait timed out");
+ break;
+ case 1:
+ break;
+ default:
+ fatal(0, "snd_pcm_wait returned %d", err);
+ }
pthread_mutex_lock(&lock);
/* ALSA is ready for more data */
- if(packets && packets->timestamp + packets->nused == next_timestamp) {
- /* Hooray, we have a packet we can play */
- const size_t samples_available = packets->nsamples - packets->nused;
+ packet_start = packets->timestamp;
+ packet_end = packets->timestamp + packets->nsamples;
+ if(ge(next_timestamp, packet_start)
+ && lt(next_timestamp, packet_end)) {
+ /* The target timestamp is somewhere in this packet */
+ const uint32_t offset = next_timestamp - packets->timestamp;
+ const uint32_t samples_available = (packets->timestamp + packets->nsamples) - next_timestamp;
const size_t frames_available = samples_available / 2;
frames_written = snd_pcm_writei(pcm,
- packets->samples_raw + packets->nused,
+ packets->samples_raw + offset,
frames_available);
if(frames_written < 0) {
- if(frames_written != -EAGAIN)
+ switch(frames_written) {
+ case -EAGAIN:
+ info("snd_pcm_wait() returned but we got -EAGAIN!");
+ break;
+ case -EPIPE:
+ error(0, "error calling snd_pcm_writei: %ld",
+ (long)frames_written);
+ escape = 1;
+ break;
+ default:
fatal(0, "error calling snd_pcm_writei: %ld",
(long)frames_written);
+ }
} else {
samples_written = frames_written * 2;
- packets->nused += samples_written;
next_timestamp += samples_written;
- if(packets->nused == packets->nsamples) {
- /* We're done with this packet */
- struct packet *p = packets;
-
- packets = p->next;
- nsamples -= p->nsamples;
- free(p);
- pthread_cond_broadcast(&cond);
- }
+ if(ge(next_timestamp, packet_end))
+ drop_first_packet();
infilling = 0;
}
} else {
/* We don't have anything to play! We'd better play some 0s. */
- static const uint16_t zeros[1024];
- size_t samples_available = 1024, frames_available;
+ static const uint16_t zeros[INFILL_SAMPLES];
+ size_t samples_available = INFILL_SAMPLES, frames_available;
- if(!infilling) {
- info("Infilling...");
- infilling = 1;
- }
- if(packets && next_timestamp + samples_available > packets->timestamp)
+ /* If the maximum infill would take us past the start of the next
+ * packet then we truncate the infill to the right amount. */
+ if(lt(packets->timestamp,
+ next_timestamp + samples_available))
samples_available = packets->timestamp - next_timestamp;
+ if((int)samples_available < 0) {
+ info("packets->timestamp: %"PRIx32" next_timestamp: %"PRIx32" next+max: %"PRIx32" available: %"PRIx32,
+ packets->timestamp, next_timestamp,
+ next_timestamp + INFILL_SAMPLES, samples_available);
+ }
frames_available = samples_available / 2;
+ if(!infilling) {
+ info("Infilling %d samples, next=%"PRIx32" packet=[%"PRIx32",%"PRIx32"]",
+ samples_available, next_timestamp,
+ packets->timestamp, packets->timestamp + packets->nsamples);
+ //infilling++;
+ }
frames_written = snd_pcm_writei(pcm,
zeros,
frames_available);
if(frames_written < 0) {
- if(frames_written != -EAGAIN)
+ switch(frames_written) {
+ case -EAGAIN:
+ info("snd_pcm_wait() returned but we got -EAGAIN!");
+ break;
+ case -EPIPE:
+ error(0, "error calling snd_pcm_writei: %ld",
+ (long)frames_written);
+ escape = 1;
+ break;
+ default:
fatal(0, "error calling snd_pcm_writei: %ld",
(long)frames_written);
- } else
+ }
+ } else {
+ samples_written = frames_written * 2;
next_timestamp += samples_written;
+ }
}
}
active = 0;
pthread_mutex_unlock(&lock);
if((err = snd_pcm_nonblock(pcm, 0)))
fatal(0, "error calling snd_pcm_nonblock: %d", err);
- if((err = snd_pcm_drain(pcm)))
- fatal(0, "error calling snd_pcm_drain: %d", err);
+ if(escape) {
+ if((err = snd_pcm_drop(pcm)))
+ fatal(0, "error calling snd_pcm_drop: %d", err);
+ escape = 0;
+ } else
+ if((err = snd_pcm_drain(pcm)))
+ fatal(0, "error calling snd_pcm_drain: %d", err);
if((err = snd_pcm_nonblock(pcm, 1)))
fatal(0, "error calling snd_pcm_nonblock: %d", err);
prepared = 0;
if(status)
fatal(0, "AudioHardwareGetProperty: %d", (int)status);
D(("mSampleRate %f", asbd.mSampleRate));
- D(("mFormatID %08"PRIx32, asbd.mFormatID));
- D(("mFormatFlags %08"PRIx32, asbd.mFormatFlags));
- D(("mBytesPerPacket %08"PRIx32, asbd.mBytesPerPacket));
- D(("mFramesPerPacket %08"PRIx32, asbd.mFramesPerPacket));
- D(("mBytesPerFrame %08"PRIx32, asbd.mBytesPerFrame));
- D(("mChannelsPerFrame %08"PRIx32, asbd.mChannelsPerFrame));
- D(("mBitsPerChannel %08"PRIx32, asbd.mBitsPerChannel));
- D(("mReserved %08"PRIx32, asbd.mReserved));
+ D(("mFormatID %08lx", asbd.mFormatID));
+ D(("mFormatFlags %08lx", asbd.mFormatFlags));
+ D(("mBytesPerPacket %08lx", asbd.mBytesPerPacket));
+ D(("mFramesPerPacket %08lx", asbd.mFramesPerPacket));
+ D(("mBytesPerFrame %08lx", asbd.mBytesPerFrame));
+ D(("mChannelsPerFrame %08lx", asbd.mChannelsPerFrame));
+ D(("mBitsPerChannel %08lx", asbd.mBitsPerChannel));
+ D(("mReserved %08lx", asbd.mReserved));
if(asbd.mFormatID != kAudioFormatLinearPCM)
fatal(0, "audio device does not support kAudioFormatLinearPCM");
status = AudioDeviceAddIOProc(adid, adioproc, 0);
xprintf("Usage:\n"
" disorder-playrtp [OPTIONS] ADDRESS [PORT]\n"
"Options:\n"
- " --help, -h Display usage message\n"
- " --version, -V Display version number\n"
- " --debug, -d Turn on debugging\n"
" --device, -D DEVICE Output device\n"
" --min, -m FRAMES Buffer low water mark\n"
- " --buffer, -b FRAMES Buffer high water mark\n");
+ " --buffer, -b FRAMES Buffer high water mark\n"
+ " --max, -x FRAMES Buffer maximum size\n"
+ " --help, -h Display usage message\n"
+ " --version, -V Display version number\n"
+ );
xfclose(stdout);
exit(0);
}
mem_init();
if(!setlocale(LC_CTYPE, "")) fatal(errno, "error calling setlocale");
- while((n = getopt_long(argc, argv, "hVdD:m:b:", options, 0)) >= 0) {
+ while((n = getopt_long(argc, argv, "hVdD:m:b:x:", options, 0)) >= 0) {
switch(n) {
case 'h': help();
case 'V': version();
case 'D': device = optarg; break;
case 'm': minbuffer = 2 * atol(optarg); break;
case 'b': readahead = 2 * atol(optarg); break;
+ case 'x': maxbuffer = 2 * atol(optarg); break;
default: fatal(0, "invalid option");
}
}
+ if(!maxbuffer)
+ maxbuffer = 4 * readahead;
argc -= optind;
argv += optind;
if(argc < 1 || argc > 2)
~mdw / disorder / blobdiff