| blob | b4c836c971abdf291a47600d7c2a160a24924b53 |
1 .TH "JACKD" "1" "!DATE!" "!VERSION!" ""
2 .SH "NAME"
3 \fBjackd\fR \- JACK Audio Connection Kit sound server
6 .SH "SYNOPSIS"
7 \fBjackd\fR [\fIoptions\fR] \fB\-d\fI backend \fR
8 [\fIbackend\-parameters\fR]
9 .br
10 \fBjackd \-\-help\fR
13 .SH "DESCRIPTION"
14 \fBjackd\fR is the JACK audio server daemon that allows JACK client
15 programs to process and route audio and MIDI data in a synchronous,
16 sample-accurate and low\-latency manner. Originally written for the
17 GNU/Linux operating system, it also runs on various Unix platforms,
18 Mac OS X and MS Windows.
19 JACK can connect a number of different client applications
20 to an audio device and also to each other. Most clients are external,
21 running in their own processes as normal applications. JACK also
22 supports internal clients, which run within the \fBjackd\fR process
23 using a loadable "plugin" interface.
25 JACK differs from other audio servers in being designed from the
26 ground up for professional audio work. It focuses on two key areas:
27 synchronous execution of all clients and low latency operation.
29 The name JACK makes a reference to the classical way of patching audio
30 connections with physical audio jack cables.
31 JACK is also a recursive acronym, that is an abbreviation which is part
32 of itself. \fIJ\fRACK \fIA\fRudio \fIC\fRonnection \fIK\fRit.
34 For the latest JACK information please consult the web site:
35 <\fBhttp://www.jackaudio.org/\fR>.
38 .SH "OPTIONS"
40 .TP
41 \fB\-d, \-\-driver \fIbackend\fR [\fIbackend\-parameters\fR ]
42 .br
43 Select the audio interface backend. The current list of supported
44 backends is: \fBalsa\fR, \fBcoreaudio\fR, \fBdummy\fR,
45 \fBfirewire\fR, \fBoss\fR \fBsun\fR and \fBportaudio\fR. They are
46 not all available on all platforms. All \fIbackend\-parameters\fR are optional.
48 .TP
49 \fB\-h, \-\-help\fR
50 .br
51 Print a brief usage message describing the main \fBjackd\fR options.
52 These do not include \fIbackend\-parameters\fR, which are listed using
53 the \fB\-\-help\fR option for each specific backend. Examples below
54 show how to list them.
56 .TP
57 \fB\-a, \-\-autoconnect\fR \fImodechar\fR
58 Select how to handle self connect requests. They can be ignore or fail,
59 on all port or just external ones. Use the \fB\-\-help\fR option to know
60 your system specific options. The default is to not restrict self connect
61 requests.
62 .TP
63 \fB\-m, \-\-no\-mlock\fR
64 Do not attempt to lock memory, even if \fB\-\-realtime\fR.
66 .TP
67 \fB\-n, \-\-name\fR \fIserver\-name\fR
68 Name this \fBjackd\fR instance \fIserver\-name\fR. If unspecified,
69 this name comes from the \fB$JACK_DEFAULT_SERVER\fR environment
70 variable.
71 (default: "default")
73 .TP
74 \fB\-p, \-\-port\-max \fI n\fR
75 Set the maximum number of ports the JACK server can manage.
76 (default: 256)
78 .TP
79 \fB\-\-replace-registry\fR
80 .br
81 Remove the shared memory registry used by all JACK server instances
82 before startup. This should rarely be used, and is intended only
83 for occasions when the structure of this registry changes in ways
84 that are incompatible across JACK versions (which is rare).
86 .TP
87 \fB\-R, \-\-realtime\fR
88 .br
89 Use realtime scheduling. This is needed for reliable low\-latency
90 performance. On many systems, it requires \fBjackd\fR to run with
91 special scheduler and memory allocation privileges, which may be
92 obtained in several ways.
93 (default: true)
95 .TP
96 \fB\-r, \-\-no-realtime\fR
97 .br
98 Do not use realtime scheduling.
100 .TP
101 \fB\-P, \-\-realtime\-priority \fIint\fR
102 When running \fB\-\-realtime\fR, set the scheduler priority to
103 \fIint\fR.
105 .TP
106 \fB\-\-silent\fR
107 Silence any output during operation.
110 .TP
111 \fB\-T, \-\-temporary\fR
112 Exit once all clients have closed their connections.
114 .TP
115 \fB\-t, \-\-timeout \fIint\fR
116 .br
117 Set client timeout limit in milliseconds.
118 In realtime mode the client timeout must be smaller than the watchdog timeout (5000 msec).
119 (default: 500)
121 .TP
122 \fB\-Z, \-\-nozombies\fR
123 .br
124 Prevent JACK from ever kicking out clients because they were too slow.
125 This cancels the effect any specified timeout value, but JACK and its clients are
126 still subject to the supervision of the watchdog thread or its equivalent.
128 .TP
129 \fB\-C, \-\-internal-session-file \fIinternal-session-file\fR
130 .br
131 Load internal clients and connections from \fIinternal-session-file\fR.
132 Each line of this configuration file starts with a command.
133 The following commands are available:
134 .br
135 \fBl(oad)\fR \fIclient-name lib-name client-args\fR
136 .br
137 With this command an internal JACK client will be instantiated.
138 \fIclient-name\fR and \fIlib-name\fR cannot contain spaces.
139 The rest of the line will be interpreted as \fIclient-args\fR and
140 sent to the client library.
141 .br
142 \fBc(on)\fR \fIsource-port destination-port\fR
143 .br
144 With this command a source port will be connected to a destination port.
145 \fIsource-port\fR and \fIdestination-port\fR cannot contain spaces.
146 .br
147 Comments are allowed, they start with \fB#\fR.
148 .br
149 An example configuration could look like the following:
150 .br
151 l inprocess1 inprocess
152 l amp1 jalv http://lv2plug.in/plugins/eg-amp
153 .br
154 c amp:out system:playback_1
156 .TP
157 \fB\-u, \-\-unlock\fR
158 .br
159 Unlock libraries GTK+, QT, FLTK, Wine.
161 .TP
162 \fB\-v, \-\-verbose\fR
163 Give verbose output.
165 .TP
166 \fB\-c, \-\-clocksource\fR (\fI h(pet) \fR | \fI s(ystem) \fR)
167 Select a specific wall clock (HPET timer, System timer).
169 .TP
170 \fB\-V, \-\-version\fR
171 Print the current JACK version number and exit.
174 .SS ALSA BACKEND OPTIONS
176 .TP
177 \fB\-C, \-\-capture\fR [ \fIname\fR ]
178 Provide only capture ports, unless combined with \-D or \-P. Optionally set
179 capture device name.
181 .TP
182 \fB\-d, \-\-device \fIname\fR
183 .br
184 The ALSA pcm device \fIname\fR to use. If none is specified, JACK will
185 use "hw:0", the first hardware card defined in \fB/etc/modules.conf\fR.
187 .TP
188 \fB\-z, \-\-dither [rectangular,triangular,shaped,none]
189 Set dithering mode. If \fBnone\fR or unspecified, dithering is off.
190 Only the first letter of the mode name is required.
192 .TP
193 \fB\-D, \-\-duplex\fR
194 Provide both capture and playback ports. Defaults to on unless only one
195 of \-P or \-C is specified.
196 (default: true)
198 .TP
199 \fB\-h, \-\-help\fR Print a brief usage message describing only the
200 \fBalsa\fR backend parameters.
202 .TP
203 \fB\-M, \-\-hwmeter\fR
204 .br
205 Enable hardware metering for devices that support it. Otherwise, use
206 software metering.
208 .TP
209 \fB\-H, \-\-hwmon\fR
210 .br
211 Enable hardware monitoring of capture ports. This is a method for
212 obtaining "zero latency" monitoring of audio input. It requires
213 support in hardware and from the underlying ALSA device driver.
215 When enabled, requests to monitor capture ports will be satisfied by
216 creating a direct signal path between audio interface input and output
217 connectors, with no processing by the host computer at all. This
218 offers the lowest possible latency for the monitored signal.
220 Presently (March 2003), only the RME Hammerfall series and cards based
221 on the ICE1712 chipset (M\-Audio Delta series, Terratec, and others)
222 support \fB\-\-hwmon\fR. In the future, some consumer cards may also
223 be supported by modifying their mixer settings.
225 Without \fB\-\-hwmon\fR, port monitoring requires JACK to read audio
226 into system memory, then copy it back out to the hardware again,
227 imposing the basic JACK system latency determined by the
228 \fB\-\-period\fR and \fB\-\-nperiods\fR parameters.
230 .TP
231 \fB\-i, \-\-inchannels \fIint\fR
232 .br
233 Number of capture channels.
234 (default: maximum supported by hardware)
236 .TP
237 \fB\-I, \-\-input\-latency\fR
238 Extra input latency (frames).
239 (default: 0)
241 .TP
242 \fB\-n, \-\-nperiods \fIint\fR
243 .br
244 Number of periods of playback latency. In seconds, this
245 corresponds to \fB\-\-nperiods\fR times \fB\-\-period\fR divided by
246 \fB\-\-rate\fR. The default is 2, the minimum allowed. For most
247 devices, there is no need for any other value with the
248 \fB\-\-realtime\fR option. Without realtime privileges or with boards
249 providing unreliable interrupts (like ymfpci), a larger value may
250 yield fewer xruns. This can also help if the system is not tuned for
251 reliable realtime scheduling.
253 For most ALSA devices, the hardware buffer has exactly
254 \fB\-\-period\fR times \fB\-\-nperiods\fR frames. Some devices demand
255 a larger buffer. If so, JACK will use the smallest possible buffer
256 containing at least \fB\-\-nperiods\fR, but the playback latency does
257 not increase.
259 For USB audio devices it is recommended to use \fB\-n 3\fR. Firewire
260 devices supported by FFADO (formerly FreeBoB) are configured with
261 \fB\-n 3\fR by default.
263 .TP
264 \fB\-o, \-\-outchannels \fIint\fR
265 .br
266 Number of playback channels.
267 (default: maximum supported by hardware)
269 .TP
270 \fB\-O, \-\-output\-latency\fR
271 Extra output latency (frames).
272 (default: 0)
274 .TP
275 \fB\-P, \-\-playback\fR [ \fIname\fR ]
276 Provide only playback ports, unless combined with \-D or \-C. Optionally set
277 playback device name.
279 .TP
280 \fB\-p, \-\-period \fIint\fR
281 .br
282 Number of frames between JACK \fBprocess()\fR calls. This
283 value must be a power of 2. If you need low
284 latency, set \fB\-p\fR as low as you can go without seeing xruns. A larger
285 period size yields higher latency, but makes xruns less likely. The JACK
286 capture latency in seconds is \fB\-\-period\fR divided by \fB\-\-rate\fR.
287 (default: 1024)
289 .TP
290 \fB\-r, \-\-rate \fIint\fR
291 Sample rate.
292 (default: 48000)
294 .TP
295 \fB\-S, \-\-shorts
296 .br
297 Try to configure card for 16\-bit samples first, only trying 32\-bits if
298 unsuccessful.
299 (default: 32\-bit samples)
301 .TP
302 \fB\-s, \-\-softmode\fR
303 .br
304 Ignore xruns reported by the ALSA driver. This makes JACK less likely
305 to disconnect unresponsive ports when running without \fB\-\-realtime\fR.
307 .TP
308 \fB\-X, \-\-midi \fR[\fIseq\fR|\fIraw\fR]
309 .br
310 Which ALSA MIDI system to provide access to. Using \fBraw\fR
311 will provide a set of JACK MIDI ports that correspond to each raw ALSA
312 device on the machine. Using \fBseq\fR will provide a set of JACK MIDI
313 ports that correspond to each ALSA "sequencer" client (which includes
314 each hardware MIDI port on the machine). \fBraw\fR provides slightly
315 better performance but does not permit JACK MIDI communication with
316 software written to use the ALSA "sequencer" API.
319 .SS COREAUDIO BACKEND PARAMETERS
321 .TP
322 \fB\-c, \-\-channels\fR
323 Maximum number of channels.
324 (default: 2)
326 .TP
327 \fB\-i, \-\-inchannels\fR
328 Maximum number of input channels.
329 (default: 2)
331 .TP
332 \fB\-o, \-\-outchannels\fR
333 Maximum number of output channels.
334 (default: 2)
336 .TP
337 \fB\-C, \-\-capture\fR
338 Whether or not to capture.
339 (default: true)
341 .TP
342 \fB\-P, \-\-playback\fR
343 Whether or not to playback.
344 (default: true)
346 .TP
347 \fB\-D, \-\-monitor\fR
348 Provide monitor ports for the output.
349 (default: false)
351 .TP
352 \fB\-D, \-\-duplex\fR
353 Capture and playback.
354 (default: true)
356 .TP
357 \fB\-r, \-\-rate\fR
358 Sample rate.
359 (default: 44100)
361 .TP
362 \fB\-p, \-\-period\fR
363 Frames per period, must be a power of 2.
364 (default: 128)
366 .TP
367 \fB\-d, \-\-device\fR
368 CoreAudio device name.
369 (default: none)
371 .TP
372 \fB\-I, \-\-input\-latency\fR
373 Extra input latency (frames).
374 (default: 0)
376 .TP
377 \fB\-O, \-\-output\-latency\fR
378 Extra output latency (frames).
379 (default: 0)
381 .TP
382 \fB\-l, \-\-list\-devices \fR
383 Display available CoreAudio devices.
384 (default: false)
386 .TP
387 \fB\-H, \-\-hog \fR
388 Take exclusive access of the audio device.
389 (default: false)
391 .TP
392 \fB\-L, \-\-async\-latency \fR
393 Extra output latency in asynchronous mode (percent).
394 (default: 100)
396 .TP
397 \fB\-G, \-\-grain \fR
398 Computation grain in RT thread (percent).
399 (default: 100)
401 .TP
402 \fB\-s, \-\-clock\-drift \fR
403 Whether or not to compensate clock drift in dynamically created aggregate device.
404 (default: false)
407 .SS DUMMY BACKEND PARAMETERS
409 .TP
410 \fB\-C, \-\-capture \fIint\fR
411 Number of capture ports.
412 (default: 2)
414 .TP
415 \fB\-P, \-\-playback \fIint\fR
416 Number of playback ports.
417 (default: 2)
419 .TP
420 \fB\-r, \-\-rate \fIint\fR
421 Sample rate.
422 (default: 48000)
424 .TP
425 \fB\-p, \-\-period \fIint\fR
426 Number of frames between JACK \fBprocess()\fR calls. This
427 value must be a power of 2. If you need low
428 latency, set \fB\-p\fR as low as you can go without seeing xruns. A larger
429 period size yields higher latency, but makes xruns less likely. The JACK
430 capture latency in seconds is \fB\-\-period\fR divided by \fB\-\-rate\fR.
431 (default: 1024)
433 .TP
434 \fB\-w, \-\-wait \fIint\fR
435 Number of usecs to wait between engine processes.
436 (default: 21333)
439 .SS NETONE BACKEND PARAMETERS
441 .TP
442 \fB\-i, \-\-audio\-ins \fIint\fR
443 Number of capture channels.
444 (default: 2)
446 .TP
447 \fB\-o, \-\-audio\-outs \fIint\fR
448 Number of playback channels.
449 (default: 2)
451 .TP
452 \fB\-I, \-\-midi\-ins \fIint\fR
453 Number of midi capture channels.
454 (default: 1)
456 .TP
457 \fB\-O, \-\-midi\-outs \fIint\fR
458 Number of midi playback channels.
459 (default: 1)
461 .TP
462 \fB\-r, \-\-rate \fIint\fR
463 Sample rate.
464 (default: 48000)
466 .TP
467 \fB\-p, \-\-period \fIint\fR
468 Frames per period.
469 (default: 1024)
471 .TP
472 \fB\-n, \-\-num\-periods \fIint\fR
473 Network latency setting in no. of periods.
474 (default: 5)
476 .TP
477 \fB\-l, \-\-listen\-port \fIint\fR
478 The socket port we are listening on for sync packets.
479 (default: 3000)
481 .TP
482 \fB\-f, \-\-factor \fIint\fR
483 Factor for sample rate reduction.
484 (default: 1)
486 .TP
487 \fB\-u, \-\-upstream\-factor \fIint\fR
488 Factor for sample rate reduction on the upstream.
489 (default: 0)
491 .TP
492 \fB\-c, \-\-celt \fIint\fR
493 Sets celt encoding and number of kbits per channel.
494 (default: 0)
496 .TP
497 \fB\-b, \-\-bit\-depth \fIint\fR
498 Sample bit\-depth (0 for float, 8 for 8bit and 16 for 16bit).
499 (default: 0)
501 .TP
502 \fB\-t, \-\-transport\-sync \fIint\fR
503 Whether or not to slave the transport to the master transport.
504 (default: true)
506 .TP
507 \fB\-a, \-\-autoconf \fIint\fR
508 Whether or not to use Autoconfig, or just start.
509 (default: true)
511 .TP
512 \fB\-R, \-\-redundancy \fIint\fR
513 Send packets N times.
514 (default: 1)
516 .TP
517 \fB\-e, \-\-native\-endian \fIint\fR
518 Don't convert samples to network byte order.
519 (default: false)
520 .TP
521 \fB\-J, \-\-jitterval \fIint\fR
522 Attempted jitterbuffer microseconds on master.
523 (default: 0)
525 .TP
526 \fB\-D, \-\-always\-deadline \fIint\fR
527 Always use deadline.
528 (default: false)
531 .SS OSS BACKEND PARAMETERS
533 .TP
534 \fB\-r, \-\-rate \fIint\fR
535 Sample rate.
536 (default: 48000)
538 .TP
539 \fB\-p, \-\-period \fIint\fR
540 Number of frames between JACK \fBprocess()\fR calls. This
541 value must be a power of 2. If you need low
542 latency, set \fB\-p\fR as low as you can go without seeing xruns. A larger
543 period size yields higher latency, but makes xruns less likely. The JACK
544 capture latency in seconds is \fB\-\-period\fR divided by \fB\-\-rate\fR.
545 (default: 1024)
547 .TP
548 \fB\-n, \-\-nperiods \fIint\fR
549 Number of periods in the hardware buffer.
550 The period size (\fB\-p\fR) times \fB\-\-nperiods\fR times four is
551 the JACK buffer size in bytes. The JACK output latency in seconds is
552 \fB\-\-nperiods\fR times \fB\-\-period\fR divided by \fB\-\-rate\fR.
553 (default: 2)
555 .TP
556 \fB\-w, \-\-wordlength \fIint\fR
557 Sample size in bits.
558 (default: 16)
560 .TP
561 \fB\-i, \-\-inchannels \fIint\fR
562 Number of capture channels.
563 (default: 2)
565 .TP
566 \fB\-o, \-\-outchannels \fIint\fR
567 Number of playback channels.
568 (default: 2)
570 .TP
571 \fB\-C, \-\-capture \fIdevice_file\fR
572 Input device for capture.
573 (default: /dev/dsp)
575 .TP
576 \fB\-P, \-\-playback \fIdevice_file\fR
577 Output device for playback.
578 (default: /dev/dsp)
580 .TP
581 \fB\-b, \-\-ignorehwbuf \fIboolean\fR
582 Whether or not to ignore hardware period size.
583 (default: false)
585 .TP
586 \fB\-I, \-\-input\-latency\fR
587 Extra input latency (frames).
588 (default: 0)
590 .TP
591 \fB\-O, \-\-output\-latency\fR
592 Extra output latency (frames).
593 (default: 0)
596 .SS SUN BACKEND PARAMETERS
598 .TP
599 \fB\-r, \-\-rate \fIint\fR
600 Sample rate.
601 (default: 48000)
603 .TP
604 \fB\-p, \-\-period \fIint\fR
605 Number of frames between JACK \fBprocess()\fR calls. This
606 value must be a power of 2. If you need low
607 latency, set \fB\-p\fR as low as you can go without seeing xruns. A larger
608 period size yields higher latency, but makes xruns less likely. The JACK
609 capture latency in seconds is \fB\-\-period\fR divided by \fB\-\-rate\fR.
610 (default: 1024)
612 .TP
613 \fB\-n, \-\-nperiods \fIint\fR
614 Number of periods in the hardware buffer.
615 The period size (\fB\-p\fR) times \fB\-\-nperiods\fR times four
616 (assuming 2 channels 16-bit samples) is the JACK buffer size in bytes.
617 The JACK output latency in seconds is \fB\-\-nperiods\fR times
618 \fB\-\-period\fR divided by \fB\-\-rate\fR.
619 (default: 2)
621 .TP
622 \fB\-w, \-\-wordlength \fIint\fR
623 Sample size in bits.
624 (default: 16)
626 .TP
627 \fB\-i, \-\-inchannels \fIint\fR
628 Number of capture channels.
629 (default: 2)
631 .TP
632 \fB\-o, \-\-outchannels \fIint\fR
633 Number of playback channels.
634 (default: 2)
636 .TP
637 \fB\-C, \-\-capture \fIdevice_file\fR
638 Input device for capture.
639 (default: /dev/audio)
641 .TP
642 \fB\-P, \-\-playback \fIdevice_file\fR
643 Output device for playback.
644 (default: /dev/audio)
646 .TP
647 \fB\-b, \-\-ignorehwbuf \fIboolean\fR
648 Whether or not to ignore hardware period size.
649 (default: false)
652 .SS PORTAUDIO BACKEND PARAMETERS
654 .TP
655 \fB\-c, \-\-channel\fR
656 Maximum number of channels.
657 (default: all available hardware channels)
659 .TP
660 \fB\-i, \-\-channelin\fR
661 Maximum number of input channels.
662 (default: all available hardware channels)
664 .TP
665 \fB\-I, \-\-input\-latency\fR
666 Extra input latency (frames).
667 (default: 0)
669 .TP
670 \fB\-o, \-\-channelout\fR
671 Maximum number of output channels.
672 (default: all available hardware channels)
674 .TP
675 \fB\-O, \-\-output\-latency\fR
676 Extra output latency (frames).
677 (default: 0)
679 .TP
680 \fB\-C, \-\-capture\fR
681 Whether or not to capture.
682 (default: true)
684 .TP
685 \fB\-P, \-\-playback\fR
686 Whether or not to playback.
687 (default: true)
689 .TP
690 \fB\-D, \-\-duplex\fR
691 Capture and playback.
692 (default: true)
694 .TP
695 \fB\-r, \-\-rate\fR
696 Sample rate.
697 (default: 48000)
699 .TP
700 \fB\-p, \-\-period\fR
701 Frames per period, must be a power of 2.
702 (default: 1024)
704 .TP
705 \fB\-n, \-\-name\fR
706 Driver name.
707 (default: none)
709 .TP
710 \fB\-z, \-\-dither\fR
711 Dithering mode.
712 (default: none)
715 .SS FIREWIRE BACKEND PARAMETERS
717 .TP
718 \fB\-d, \-\-device \fIname\fR
719 .br
720 The Firewire device \fIname\fR to use. If none is specified, JACK will try
721 to use "hw:0". To get a list of available Firewire devices, see
722 \fBffado\-test\fR. It's recommended to use the GUID of a Firewire device
723 to rule out any ambiguities. Once the GUID of the device is known
724 ("ffado-test ListDevices"), it can be used like
725 \fB\-dguid:0xff2584e39b078a2e\fR to tell JACK which interface to use.
726 Sometimes resetting the Firewire bus can help ("ffado-test BusReset") if
727 there is any problem.
728 (default: hw:0)
730 .TP
731 \fB\-p, \-\-period \fIint\fR
732 .br
733 Number of frames between JACK \fBprocess()\fR calls. This
734 value must be a power of 2. If you need low latency, set \fB\-p\fR as
735 low as you can go without seeing xruns. A larger period size yields higher
736 latency, but makes xruns less likely. The JACK capture latency in seconds
737 is \fB\-\-period\fR divided by \fB\-\-rate\fR.
738 (default: 1024)
740 .TP
741 \fB\-n, \-\-nperiods \fIint\fR
742 .br
743 Number of periods of playback latency. Value must be greater or
744 equal 2. In seconds, this corresponds to \fB\-\-nperiods\fR times \fB\-\-period\fR
745 divided by \fB\-\-rate\fR.
746 (default: 3)
748 .TP
749 \fB\-r, \-\-rate \fIint\fR
750 Sample rate.
751 (default: 48000)
753 .TP
754 \fB\-C, \-\-capture\fR [ \fIname\fR ]
755 Provide only capture ports, unless combined with \-D or \-P. Optionally set
756 capture device name.
758 .TP
759 \fB\-P, \-\-playback\fR [ \fIname\fR ]
760 Provide only playback ports, unless combined with \-D or \-C. Optionally set
761 playback device name.
763 .TP
764 \fB\-D, \-\-duplex\fR
765 Provide both capture and playback ports. This option is the default behaviour
766 and can normally be omitted.
767 \-D can not be combined with \-P or \-C.
769 .TP
770 \fB\-I, \-\-input\-latency\fR
771 Extra input latency (frames).
772 (default: 0)
774 .TP
775 \fB\-O, \-\-output\-latency\fR
776 Extra output latency (frames).
777 (default: 0)
779 .TP
780 \fB\-v, \-\-verbose
781 .br
782 libffado verbose level.
783 (default: 3)
785 .TP
786 \fB\-X, \-\-snoop\fR
787 .br
788 Snoop Firewire traffic.
789 (default: false)
791 .TP
792 \fB\-h, \-\-help\fR Print a brief usage message describing only the
793 \fBfirewire\fR backend parameters.
796 .SH "EXAMPLES"
798 .PP
799 Print usage message for the parameters specific to each backend.
801 .IP
802 \fBjackd \-d alsa \-\-help\fR
803 .br
804 \fBjackd \-d coreaudio \-\-help\fR
805 .br
806 \fBjackd \-d net \-\-help\fR
807 .br
808 \fBjackd \-d dummy \-\-help\fR
809 .br
810 \fBjackd \-d firewire \-\-help\fR
811 .br
812 \fBjackd \-d oss \-\-help\fR
813 .br
814 \fBjackd \-d sun \-\-help\fR
815 .br
816 \fBjackd \-d portaudio \-\-help\fR
817 .PP
818 Run the JACK daemon with realtime priority using the first ALSA
819 hardware card defined in \fB/etc/modules.conf\fR.
821 .IP
822 \fBjackstart \-\-realtime \-\-driver=alsa\fR
823 .PP
824 Run the JACK daemon with low latency giving verbose output, which can
825 be helpful for trouble\-shooting system latency problems. A
826 reasonably well\-tuned system with a good sound card and a
827 low\-latency kernel can handle these values reliably. Some can do
828 better. If you get xrun messages, try a larger buffer. Tuning a
829 system for low latency can be challenging. Please consult the JACK FAQ
830 for more suggestions.
832 .IP
833 \fBjackstart \-Rv \-d alsa \-p 128 \-n 2 \-r 44100\fR
834 .PP
835 Run \fBjackd\fR with realtime priority using the "sblive" ALSA device
836 defined in ~/.asoundrc. Apply shaped dithering to playback audio.
838 .IP
839 \fBjackd \-R \-d alsa \-d sblive \-\-dither=shaped\fR
840 .PP
841 Run \fBjackd\fR with no special privileges using the second ALSA
842 hardware card defined in \fB/etc/modules.conf\fR. Any xruns reported
843 by the ALSA backend will be ignored. The larger buffer helps reduce
844 data loss. Rectangular dithering will be used for playback.
846 .IP
847 \fBjackd \-d alsa \-d hw:1 \-p2048 \-n3 \-\-softmode \-zr\fR
848 .PP
849 Run \fBjackd\fR in full\-duplex mode using the ALSA hw:0,0 device for
850 playback and the hw:0,2 device for capture.
852 .IP
853 \fBjackd \-d alsa \-P hw:0,0 \-C hw:0,2\fR
854 .PP
855 Run \fBjackd\fR in playback\-only mode using the ALSA hw:0,0 device.
857 .IP
858 \fBjackd \-d alsa \-P hw:0,0\fR
861 .SH "ENVIRONMENT"
862 .br
863 JACK is evolving a mechanism for automatically starting the server
864 when needed. Any client started without a running JACK server will
865 attempt to start one itself using the command line found in the first
866 line of \fB$HOME/.jackdrc\fR if it exists, or \fB/etc/jackdrc\fR if it
867 does not. If neither file exists, a built\-in default command will be
868 used, including the \fB\-T\fR flag, which causes the server to shut
869 down when all clients have exited.
871 As a transition, this only happens when \fB$JACK_START_SERVER\fR is
872 defined in the environment of the calling process. In the future this
873 will become normal behavior. In either case, defining
874 \fB$JACK_NO_START_SERVER\fR disables this feature.
876 To change where JACK looks for the backend drivers, set
877 \fB$JACK_DRIVER_DIR\fR.
879 \fB$JACK_DEFAULT_SERVER\fR specifies the default server name. If not
880 defined, the string "default" is used. If set in their respective
881 environments, this affects \fBjackd\fR unless its \fB\-\-name\fR
882 parameter is set, and all JACK clients unless they pass an explicit
883 name to \fBjack_client_open()\fR.
885 Defining \fB$JACK_NO_AUDIO_RESERVATION\fR will bypass audio device
886 reservation via session bus (DBus). This can be useful if JACK
887 was compiled with DBus support but should run on a headless system.
889 \fB$JACK_PROMISCUOUS_SERVER\fR enables an alternate way of handling the various
890 shared resources (Unix sockets, semaphores, ...). In this mode, the generated
891 names will not contain the user id anymore, and the permissions of those
892 resources will be relaxed, allowing clients from different users to talk with
893 the same server. Moreover, on platforms that support it (all POSIX variants),
894 if set to a valid Unix group name or id, the permissions will be restricted to
895 that group, so only members of that group will be able to launch clients that
896 talk to this server. Important note: it must be set with the same value for
897 both server and clients to work as expected.
899 .SH "SEE ALSO:"
900 .PP
901 <\fBhttp://www.jackaudio.org/\fR>
902 .br
903 The official JACK website with news, docs and a list of JACK clients.
904 .PP
905 <\fBhttp://www.github.com/jackaudio/\fR>
906 .br
907 The official JACK github code repository. Pull requests are welcome.
908 .PP
909 <\fBhttp://lists.jackaudio.org/listinfo.cgi/jack-devel-jackaudio.org\fR>
910 .br
911 The JACK developers' mailing list. Subscribe to take part in
912 development of JACK or JACK clients. User questions are also welcome,
913 there is no user-specific mailing list.
914 .PP
915 <\fBhttp://www.jackosx.com/\fR>
916 .br
917 Tools specific to the Mac OS X version of JACK.
918 .PP
919 <\fBhttp://www.alsa\-project.org/\fR>
920 .br
921 The Advanced Linux Sound Architecture.
922 .PP
923 <\fBhttp://www.ffado.org/\fR>
924 .br
925 The Free Firewire Audio Drivers (FFADO) Site.
926 .PP
927 <\fBirc.freenode.net#jack\fR>
928 .br
929 Join the JACK community with your favourite IRC client.
932 .SH "BUGS"
933 Please report bugs as issues to the corresponding repository:
934 .br
935 <\fBhttp://www.github.com/jackaudio/\fR>
938 .SH "AUTHORS"
939 Architect and original implementer: Paul Davis
940 .PP
941 Original design group: Paul Davis, David Olofson, Kai Vehmanen, Benno Sennoner,
942 Richard Guenther and other members of the Linux Audio Developers group.
943 .PP
944 Programming: Paul Davis, Jack O'Quin, Taybin Rutkin, Stéphane Letz, Fernando
945 Pablo Lopez-Lezcano, Steve Harris, Jeremy Hall, Andy Wingo, Kai
946 Vehmanen, Melanie Thielker, Jussi Laako, Tilman Linneweh, Johnny
947 Petrantoni, Torben Hohn.
948 .PP
949 Manpage written by Stefan Schwandter, Jack O'Quin, Alexandre Prokoudine and Thomas Brand.
950 .PP
951 Create a PDF file from this manpage:
952 .IP
953 \fBman -t jackd | ps2pdf - > jackd.pdf\fR