2 * This file is part of DisOrder.
3 * Copyright (C) 2007 Richard Kettlewell
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
27 #include <sys/socket.h>
28 #include <sys/types.h>
29 #include <sys/socket.h>
36 #include "configuration.h"
42 #if HAVE_COREAUDIO_AUDIOHARDWARE_H
43 # include <CoreAudio/AudioHardware.h>
46 #include <alsa/asoundlib.h>
49 #define readahead linux_headers_are_borked
51 /** @brief RTP socket */
54 /** @brief Output device */
55 static const char *device
;
57 /** @brief Maximum samples per packet we'll support
59 * NB that two channels = two samples in this program.
61 #define MAXSAMPLES 2048
63 /** @brief Minimum buffer size
65 * We'll stop playing if there's only this many samples in the buffer. */
66 static unsigned minbuffer
= 2 * 44100 / 10; /* 0.2 seconds */
68 /** @brief Maximum sample size
70 * The maximum supported size (in bytes) of one sample. */
71 #define MAXSAMPLESIZE 2
73 /** @brief Buffer size
75 * We'll only start playing when this many samples are available. */
76 static unsigned readahead
= 4 * 2 * 44100; /* 4 seconds */
78 /** @brief Number of samples to infill by in one go */
79 #define INFILL_SAMPLES (44100 * 2) /* 1s */
81 #define MAXBUFFER (3 * 88200) /* maximum buffer contents */
83 /** @brief Received packet
85 * Packets are recorded in an ordered linked list. */
87 /** @brief Pointer to next packet
88 * The next packet might not be immediately next: if packets are dropped
89 * or mis-ordered there may be gaps at any given moment. */
91 /** @brief Number of samples in this packet */
93 /** @brief Timestamp from RTP packet
95 * NB that "timestamps" are really sample counters.*/
97 #if HAVE_COREAUDIO_AUDIOHARDWARE_H
98 /** @brief Converted sample data */
99 float samples_float
[MAXSAMPLES
];
101 /** @brief Raw sample data */
102 unsigned char samples_raw
[MAXSAMPLES
* MAXSAMPLESIZE
];
106 /** @brief Total number of samples available */
107 static unsigned long nsamples
;
109 /** @brief Linked list of packets
111 * In ascending order of timestamp. */
112 static struct packet
*packets
;
114 /** @brief Timestamp of next packet to play.
116 * This is set to the timestamp of the last packet, plus the number of
117 * samples it contained. Only valid if @ref active is nonzero.
119 static uint32_t next_timestamp
;
121 /** @brief True if actively playing
123 * This is true when playing and false when just buffering. */
126 /** @brief Lock protecting @ref packets */
127 static pthread_mutex_t lock
= PTHREAD_MUTEX_INITIALIZER
;
129 /** @brief Condition variable signalled whenever @ref packets is changed */
130 static pthread_cond_t cond
= PTHREAD_COND_INITIALIZER
;
132 static const struct option options
[] = {
133 { "help", no_argument
, 0, 'h' },
134 { "version", no_argument
, 0, 'V' },
135 { "debug", no_argument
, 0, 'd' },
136 { "device", required_argument
, 0, 'D' },
137 { "min", required_argument
, 0, 'm' },
138 { "buffer", required_argument
, 0, 'b' },
142 /** @brief Return true iff a < b in sequence-space arithmetic */
143 static inline int lt(uint32_t a
, uint32_t b
) {
144 return (uint32_t)(a
- b
) & 0x80000000;
147 /** @brief Return true iff a >= b in sequence-space arithmetic */
148 static inline int ge(uint32_t a
, uint32_t b
) {
152 /** @brief Return true iff a > b in sequence-space arithmetic */
153 static inline int gt(uint32_t a
, uint32_t b
) {
157 /** @brief Return true iff a <= b in sequence-space arithmetic */
158 static inline int le(uint32_t a
, uint32_t b
) {
162 /** @brief Background thread collecting samples
164 * This function collects samples, perhaps converts them to the target format,
165 * and adds them to the packet list. */
166 static void *listen_thread(void attribute((unused
)) *arg
) {
167 struct packet
*p
= 0, **pp
;
170 struct rtp_header header
;
171 uint8_t bytes
[sizeof(uint16_t) * MAXSAMPLES
+ sizeof (struct rtp_header
)];
173 const uint16_t *const samples
= (uint16_t *)(packet
.bytes
174 + sizeof (struct rtp_header
));
178 p
= xmalloc(sizeof *p
);
179 n
= read(rtpfd
, packet
.bytes
, sizeof packet
.bytes
);
185 fatal(errno
, "error reading from socket");
188 /* Ignore too-short packets */
189 if((size_t)n
<= sizeof (struct rtp_header
))
191 p
->timestamp
= ntohl(packet
.header
.timestamp
);
192 /* Ignore packets in the past */
193 if(active
&& lt(p
->timestamp
, next_timestamp
)) {
194 info("dropping old packet, timestamp=%"PRIx32
" < %"PRIx32
,
195 p
->timestamp
, next_timestamp
);
198 /* Convert to target format */
199 switch(packet
.header
.mpt
& 0x7F) {
201 p
->nsamples
= (n
- sizeof (struct rtp_header
)) / sizeof(uint16_t);
202 #if HAVE_COREAUDIO_AUDIOHARDWARE_H
203 /* Convert to what Core Audio expects */
204 for(n
= 0; n
< p
->nsamples
; ++n
)
205 p
->samples_float
[n
] = (int16_t)ntohs(samples
[n
]) * (0.5f
/ 32767);
207 /* ALSA can do any necessary conversion itself (though it might be better
208 * to do any necessary conversion in the background) */
209 memcpy(p
->samples_raw
, samples
, n
- sizeof (struct rtp_header
));
212 /* TODO support other RFC3551 media types (when the speaker does) */
214 fatal(0, "unsupported RTP payload type %d",
215 packet
.header
.mpt
& 0x7F);
217 pthread_mutex_lock(&lock
);
218 /* Stop reading if we've reached the maximum.
220 * This is rather unsatisfactory: it means that if packets get heavily
221 * out of order then we guarantee dropouts. But for now... */
222 while(nsamples
>= MAXBUFFER
)
223 pthread_cond_wait(&cond
, &lock
);
225 *pp
&& lt((*pp
)->timestamp
, p
->timestamp
);
228 /* So now either !*pp or *pp >= p */
229 if(*pp
&& p
->timestamp
== (*pp
)->timestamp
) {
230 /* *pp == p; a duplicate. Ideally we avoid the translation step here,
231 * but we'll worry about that another time. */
235 nsamples
+= p
->nsamples
;
236 pthread_cond_broadcast(&cond
);
237 p
= 0; /* we've consumed this packet */
239 pthread_mutex_unlock(&lock
);
243 #if HAVE_COREAUDIO_AUDIOHARDWARE_H
244 /** @brief Callback from Core Audio */
245 static OSStatus
adioproc(AudioDeviceID inDevice
,
246 const AudioTimeStamp
*inNow
,
247 const AudioBufferList
*inInputData
,
248 const AudioTimeStamp
*inInputTime
,
249 AudioBufferList
*outOutputData
,
250 const AudioTimeStamp
*inOutputTime
,
251 void *inClientData
) {
252 UInt32 nbuffers
= outOutputData
->mNumberBuffers
;
253 AudioBuffer
*ab
= outOutputData
->mBuffers
;
254 float *samplesOut
; /* where to write samples to */
255 size_t samplesOutLeft
; /* space left */
256 size_t samplesInLeft
;
257 size_t samplesToCopy
;
259 pthread_mutex_lock(&lock
);
260 samplesOut
= ab
->data
;
261 samplesOutLeft
= ab
->mDataByteSize
/ sizeof (float);
262 while(packets
&& nbuffers
> 0) {
263 if(packets
->used
== packets
->nsamples
) {
264 /* TODO if we dropped a packet then we should introduce a gap here */
265 struct packet
*const p
= packets
;
268 pthread_cond_broadcast(&cond
);
271 if(samplesOutLeft
== 0) {
274 samplesOut
= ab
->data
;
275 samplesOutLeft
= ab
->mDataByteSize
/ sizeof (float);
278 /* Now: (1) there is some data left to read
279 * (2) there is some space to put it */
280 samplesInLeft
= packets
->nsamples
- packets
->used
;
281 samplesToCopy
= (samplesInLeft
< samplesOutLeft
282 ? samplesInLeft
: samplesOutLeft
);
283 memcpy(samplesOut
, packet
->samples
+ packets
->used
, samplesToCopy
);
284 packets
->used
+= samplesToCopy
;
285 samplesOut
+= samplesToCopy
;
286 samesOutLeft
-= samplesToCopy
;
288 pthread_mutex_unlock(&lock
);
293 /** @brief Play an RTP stream
295 * This is the guts of the program. It is responsible for:
296 * - starting the listening thread
297 * - opening the audio device
298 * - reading ahead to build up a buffer
299 * - arranging for audio to be played
300 * - detecting when the buffer has got too small and re-buffering
302 static void play_rtp(void) {
305 /* We receive and convert audio data in a background thread */
306 pthread_create(<id
, 0, listen_thread
, 0);
310 snd_pcm_hw_params_t
*hwparams
;
311 snd_pcm_sw_params_t
*swparams
;
312 /* Only support one format for now */
313 const int sample_format
= SND_PCM_FORMAT_S16_BE
;
314 unsigned rate
= 44100;
315 const int channels
= 2;
316 const int samplesize
= channels
* sizeof(uint16_t);
317 snd_pcm_uframes_t pcm_bufsize
= MAXSAMPLES
* samplesize
* 3;
318 /* If we can write more than this many samples we'll get a wakeup */
319 const int avail_min
= 256;
320 snd_pcm_sframes_t frames_written
;
321 size_t samples_written
;
324 int infilling
= 0, escape
= 0;
326 uint32_t packet_start
, packet_end
;
329 if((err
= snd_pcm_open(&pcm
,
330 device ? device
: "default",
331 SND_PCM_STREAM_PLAYBACK
,
333 fatal(0, "error from snd_pcm_open: %d", err
);
334 /* Set up 'hardware' parameters */
335 snd_pcm_hw_params_alloca(&hwparams
);
336 if((err
= snd_pcm_hw_params_any(pcm
, hwparams
)) < 0)
337 fatal(0, "error from snd_pcm_hw_params_any: %d", err
);
338 if((err
= snd_pcm_hw_params_set_access(pcm
, hwparams
,
339 SND_PCM_ACCESS_RW_INTERLEAVED
)) < 0)
340 fatal(0, "error from snd_pcm_hw_params_set_access: %d", err
);
341 if((err
= snd_pcm_hw_params_set_format(pcm
, hwparams
,
343 fatal(0, "error from snd_pcm_hw_params_set_format (%d): %d",
345 if((err
= snd_pcm_hw_params_set_rate_near(pcm
, hwparams
, &rate
, 0)) < 0)
346 fatal(0, "error from snd_pcm_hw_params_set_rate (%d): %d",
348 if((err
= snd_pcm_hw_params_set_channels(pcm
, hwparams
,
350 fatal(0, "error from snd_pcm_hw_params_set_channels (%d): %d",
352 if((err
= snd_pcm_hw_params_set_buffer_size_near(pcm
, hwparams
,
354 fatal(0, "error from snd_pcm_hw_params_set_buffer_size (%d): %d",
355 MAXSAMPLES
* samplesize
* 3, err
);
356 if((err
= snd_pcm_hw_params(pcm
, hwparams
)) < 0)
357 fatal(0, "error calling snd_pcm_hw_params: %d", err
);
358 /* Set up 'software' parameters */
359 snd_pcm_sw_params_alloca(&swparams
);
360 if((err
= snd_pcm_sw_params_current(pcm
, swparams
)) < 0)
361 fatal(0, "error calling snd_pcm_sw_params_current: %d", err
);
362 if((err
= snd_pcm_sw_params_set_avail_min(pcm
, swparams
, avail_min
)) < 0)
363 fatal(0, "error calling snd_pcm_sw_params_set_avail_min %d: %d",
365 if((err
= snd_pcm_sw_params(pcm
, swparams
)) < 0)
366 fatal(0, "error calling snd_pcm_sw_params: %d", err
);
371 pthread_mutex_lock(&lock
);
373 /* Wait for the buffer to fill up a bit */
374 info("Buffering...");
375 while(nsamples
< readahead
)
376 pthread_cond_wait(&cond
, &lock
);
378 if((err
= snd_pcm_prepare(pcm
)))
379 fatal(0, "error calling snd_pcm_prepare: %d", err
);
382 /* Start at the first available packet */
383 next_timestamp
= packets
->timestamp
;
388 /* Wait until the buffer empties out */
389 while(nsamples
>= minbuffer
&& !escape
) {
391 if(now
> logged
+ 10) {
393 info("%lu samples in buffer (%lus)", nsamples
,
394 nsamples
/ (44100 * 2));
397 && ge(next_timestamp
, packets
->timestamp
+ packets
->nsamples
)) {
398 struct packet
*p
= packets
;
400 info("dropping buffered past packet %"PRIx32
" < %"PRIx32
,
401 packets
->timestamp
, next_timestamp
);
405 assert(lt(p
->timestamp
, packets
->timestamp
));
406 nsamples
-= p
->nsamples
;
408 pthread_cond_broadcast(&cond
);
411 /* Wait for ALSA to ask us for more data */
412 pthread_mutex_unlock(&lock
);
413 snd_pcm_wait(pcm
, -1);
414 pthread_mutex_lock(&lock
);
415 /* ALSA is ready for more data */
416 packet_start
= packets
->timestamp
;
417 packet_end
= packets
->timestamp
+ packets
->nsamples
;
418 if(ge(next_timestamp
, packet_start
)
419 && lt(next_timestamp
, packet_end
)) {
420 /* The target timestamp is somewhere in this packet */
421 const uint32_t offset
= next_timestamp
- packets
->timestamp
;
422 const uint32_t samples_available
= (packets
->timestamp
+ packets
->nsamples
) - next_timestamp
;
423 const size_t frames_available
= samples_available
/ 2;
425 frames_written
= snd_pcm_writei(pcm
,
426 packets
->samples_raw
+ offset
,
428 if(frames_written
< 0) {
429 switch(frames_written
) {
431 info("snd_pcm_wait() returned but we got -EAGAIN!");
434 error(0, "error calling snd_pcm_writei: %ld",
435 (long)frames_written
);
439 fatal(0, "error calling snd_pcm_writei: %ld",
440 (long)frames_written
);
443 samples_written
= frames_written
* 2;
444 next_timestamp
+= samples_written
;
445 if(ge(next_timestamp
, packet_end
)) {
446 /* We're done with this packet */
447 struct packet
*p
= packets
;
451 assert(lt(p
->timestamp
, packets
->timestamp
));
452 nsamples
-= p
->nsamples
;
454 pthread_cond_broadcast(&cond
);
459 /* We don't have anything to play! We'd better play some 0s. */
460 static const uint16_t zeros
[INFILL_SAMPLES
];
461 size_t samples_available
= INFILL_SAMPLES
, frames_available
;
463 /* If the maximum infill would take us past the start of the next
464 * packet then we truncate the infill to the right amount. */
465 if(lt(packets
->timestamp
,
466 next_timestamp
+ samples_available
))
467 samples_available
= packets
->timestamp
- next_timestamp
;
468 if((int)samples_available
< 0) {
469 info("packets->timestamp: %"PRIx32
" next_timestamp: %"PRIx32
" next+max: %"PRIx32
" available: %"PRIx32
,
470 packets
->timestamp
, next_timestamp
,
471 next_timestamp
+ INFILL_SAMPLES
, samples_available
);
473 frames_available
= samples_available
/ 2;
475 info("Infilling %d samples, next=%"PRIx32
" but packet=%"PRIx32
,
476 samples_available
, next_timestamp
, packets
->timestamp
);
479 frames_written
= snd_pcm_writei(pcm
,
482 if(frames_written
< 0) {
483 switch(frames_written
) {
485 info("snd_pcm_wait() returned but we got -EAGAIN!");
488 error(0, "error calling snd_pcm_writei: %ld",
489 (long)frames_written
);
493 fatal(0, "error calling snd_pcm_writei: %ld",
494 (long)frames_written
);
497 samples_written
= frames_written
* 2;
498 next_timestamp
+= samples_written
;
503 /* We stop playing for a bit until the buffer re-fills */
504 pthread_mutex_unlock(&lock
);
505 if((err
= snd_pcm_nonblock(pcm
, 0)))
506 fatal(0, "error calling snd_pcm_nonblock: %d", err
);
508 if((err
= snd_pcm_drop(pcm
)))
509 fatal(0, "error calling snd_pcm_drop: %d", err
);
512 if((err
= snd_pcm_drain(pcm
)))
513 fatal(0, "error calling snd_pcm_drain: %d", err
);
514 if((err
= snd_pcm_nonblock(pcm
, 1)))
515 fatal(0, "error calling snd_pcm_nonblock: %d", err
);
517 pthread_mutex_lock(&lock
);
521 #elif HAVE_COREAUDIO_AUDIOHARDWARE_H
526 AudioStreamBasicDescription asbd
;
528 /* If this looks suspiciously like libao's macosx driver there's an
529 * excellent reason for that... */
531 /* TODO report errors as strings not numbers */
532 propertySize
= sizeof adid
;
533 status
= AudioHardwareGetProperty(kAudioHardwarePropertyDefaultOutputDevice
,
534 &propertySize
, &adid
);
536 fatal(0, "AudioHardwareGetProperty: %d", (int)status
);
537 if(adid
== kAudioDeviceUnknown
)
538 fatal(0, "no output device");
539 propertySize
= sizeof asbd
;
540 status
= AudioDeviceGetProperty(adid
, 0, false,
541 kAudioDevicePropertyStreamFormat
,
542 &propertySize
, &asbd
);
544 fatal(0, "AudioHardwareGetProperty: %d", (int)status
);
545 D(("mSampleRate %f", asbd
.mSampleRate
));
546 D(("mFormatID %08"PRIx32
, asbd
.mFormatID
));
547 D(("mFormatFlags %08"PRIx32
, asbd
.mFormatFlags
));
548 D(("mBytesPerPacket %08"PRIx32
, asbd
.mBytesPerPacket
));
549 D(("mFramesPerPacket %08"PRIx32
, asbd
.mFramesPerPacket
));
550 D(("mBytesPerFrame %08"PRIx32
, asbd
.mBytesPerFrame
));
551 D(("mChannelsPerFrame %08"PRIx32
, asbd
.mChannelsPerFrame
));
552 D(("mBitsPerChannel %08"PRIx32
, asbd
.mBitsPerChannel
));
553 D(("mReserved %08"PRIx32
, asbd
.mReserved
));
554 if(asbd
.mFormatID
!= kAudioFormatLinearPCM
)
555 fatal(0, "audio device does not support kAudioFormatLinearPCM");
556 status
= AudioDeviceAddIOProc(adid
, adioproc
, 0);
558 fatal(0, "AudioDeviceAddIOProc: %d", (int)status
);
559 pthread_mutex_lock(&lock
);
561 /* Wait for the buffer to fill up a bit */
562 while(nsamples
< readahead
)
563 pthread_cond_wait(&cond
, &lock
);
564 /* Start playing now */
565 status
= AudioDeviceStart(adid
, adioproc
);
567 fatal(0, "AudioDeviceStart: %d", (int)status
);
568 /* Wait until the buffer empties out */
569 while(nsamples
>= minbuffer
)
570 pthread_cond_wait(&cond
, &lock
);
571 /* Stop playing for a bit until the buffer re-fills */
572 status
= AudioDeviceStop(adid
, adioproc
);
574 fatal(0, "AudioDeviceStop: %d", (int)status
);
579 # error No known audio API
583 /* display usage message and terminate */
584 static void help(void) {
586 " disorder-playrtp [OPTIONS] ADDRESS [PORT]\n"
588 " --help, -h Display usage message\n"
589 " --version, -V Display version number\n"
590 " --debug, -d Turn on debugging\n"
591 " --device, -D DEVICE Output device\n"
592 " --min, -m FRAMES Buffer low water mark\n"
593 " --buffer, -b FRAMES Buffer high water mark\n");
598 /* display version number and terminate */
599 static void version(void) {
600 xprintf("disorder-playrtp version %s\n", disorder_version_string
);
605 int main(int argc
, char **argv
) {
607 struct addrinfo
*res
;
608 struct stringlist sl
;
611 static const struct addrinfo prefs
= {
623 if(!setlocale(LC_CTYPE
, "")) fatal(errno
, "error calling setlocale");
624 while((n
= getopt_long(argc
, argv
, "hVdD:m:b:", options
, 0)) >= 0) {
628 case 'd': debugging
= 1; break;
629 case 'D': device
= optarg
; break;
630 case 'm': minbuffer
= 2 * atol(optarg
); break;
631 case 'b': readahead
= 2 * atol(optarg
); break;
632 default: fatal(0, "invalid option");
637 if(argc
< 1 || argc
> 2)
638 fatal(0, "usage: disorder-playrtp [OPTIONS] ADDRESS [PORT]");
641 /* Listen for inbound audio data */
642 if(!(res
= get_address(&sl
, &prefs
, &sockname
)))
644 if((rtpfd
= socket(res
->ai_family
,
646 res
->ai_protocol
)) < 0)
647 fatal(errno
, "error creating socket");
648 if(bind(rtpfd
, res
->ai_addr
, res
->ai_addrlen
) < 0)
649 fatal(errno
, "error binding socket to %s", sockname
);