Annotation of src/usr.bin/aucat/aucat.1, Revision 1.46
1.46 ! ratchov 1: .\" $OpenBSD: aucat.1,v 1.45 2009/02/03 19:44:58 ratchov Exp $
1.1 kstailey 2: .\"
1.16 ratchov 3: .\" Copyright (c) 2006 Alexandre Ratchov <alex@caoua.org>
1.1 kstailey 4: .\"
1.16 ratchov 5: .\" Permission to use, copy, modify, and distribute this software for any
6: .\" purpose with or without fee is hereby granted, provided that the above
7: .\" copyright notice and this permission notice appear in all copies.
1.1 kstailey 8: .\"
1.16 ratchov 9: .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10: .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11: .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12: .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13: .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14: .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15: .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
1.1 kstailey 16: .\"
1.46 ! ratchov 17: .Dd $Mdocdate: February 3 2009 $
1.1 kstailey 18: .Dt AUCAT 1
1.5 aaron 19: .Os
1.1 kstailey 20: .Sh NAME
21: .Nm aucat
1.16 ratchov 22: .Nd manipulate linear audio streams
1.1 kstailey 23: .Sh SYNOPSIS
24: .Nm aucat
1.16 ratchov 25: .Bk -words
1.42 ratchov 26: .Op Fl lnu
1.26 ratchov 27: .Op Fl b Ar nsamples
1.16 ratchov 28: .Op Fl C Ar min : Ns Ar max
29: .Op Fl c Ar min : Ns Ar max
30: .Op Fl e Ar enc
1.9 millert 31: .Op Fl f Ar device
1.16 ratchov 32: .Op Fl h Ar fmt
33: .Op Fl i Ar file
1.37 ratchov 34: .Op Fl m Ar mode
1.16 ratchov 35: .Op Fl o Ar file
36: .Op Fl r Ar rate
1.40 jmc 37: .Op Fl s Ar socket
1.30 ratchov 38: .Op Fl v Ar volume
1.22 ratchov 39: .Op Fl x Ar policy
1.16 ratchov 40: .Ek
1.1 kstailey 41: .Sh DESCRIPTION
42: The
1.7 aaron 43: .Nm
1.16 ratchov 44: utility can record one input stream
45: and store it on multiple destination files,
46: doing the necessary conversions on the fly.
1.17 jmc 47: It can play, convert, and mix multiple input files simultaneously.
1.9 millert 48: .Nm
1.16 ratchov 49: also has a legacy mode that works like previous versions of
50: .Nm ,
51: which does not convert on the fly and supports playback of .au files.
1.17 jmc 52: .Pp
1.16 ratchov 53: The options are as follows:
1.26 ratchov 54: .Bl -tag -width Ds
55: .It Fl b Ar nsamples
56: The buffer size in frames.
57: This is the number of samples that will be buffered before being played
58: and controls the playback latency.
1.25 jmc 59: .It Xo
60: .Fl C Ar min : Ns Ar max ,
61: .Fl c Ar min : Ns Ar max
62: .Xc
1.26 ratchov 63: The range of channel numbers on the record or playback stream, respectively.
1.17 jmc 64: The default is 0:1, i.e. stereo.
1.26 ratchov 65: .It Fl e Ar enc
66: Encoding of the playback or recording stream (see below).
1.17 jmc 67: The default is signed, 16-bit, native byte order.
68: .It Fl f Ar device
69: The
70: .Xr audio 4
71: device to use for playing and/or recording.
72: The default is
73: .Pa /dev/audio .
1.26 ratchov 74: .It Fl h Ar fmt
75: File format of the playback or record stream (see below).
1.17 jmc 76: The default is auto.
1.16 ratchov 77: .It Fl i Ar file
78: Add this file to the list of files to play.
79: If the option argument is
80: .Sq -
81: then standard input will be used.
1.26 ratchov 82: .It Fl l
1.35 ratchov 83: Listen for incoming connections on Unix domain sockets.
1.39 jmc 84: This allows clients to use
1.26 ratchov 85: .Nm
86: instead of the regular
87: .Xr audio 4
88: device for audio input and output
89: in order to share the physical device with other clients.
1.45 ratchov 90: The default socket name is
91: .Pa default
92: but other names can be used with the
1.35 ratchov 93: .Fl s
94: option.
1.37 ratchov 95: .It Fl m Ar mode
96: Set the server mode.
97: Valid modes are
1.39 jmc 98: .Ar play ,
99: .Ar rec ,
1.37 ratchov 100: and
1.39 jmc 101: .Ar duplex ,
102: for play-only, record-only, and full-duplex, respectively.
1.37 ratchov 103: The default is
1.39 jmc 104: .Ar duplex .
1.42 ratchov 105: .It Fl n
106: Loopback mode.
107: Instead of using an audio device, send input streams
108: to the output, processing them on the fly.
109: This mode is useful to mix, demultiplex, resample or reencode
1.43 jmc 110: audio files offline.
1.16 ratchov 111: .It Fl o Ar file
112: Add this file to the list of files in which to store recorded samples.
113: If the option argument is
114: .Sq -
115: then standard output will be used.
1.26 ratchov 116: .It Fl r Ar rate
117: Sample rate in Hertz of the playback or record stream.
1.17 jmc 118: The default is 44100Hz.
1.40 jmc 119: .It Fl s Ar socket
1.45 ratchov 120: Add the name
1.40 jmc 121: .Ar socket
122: to the list of sockets to listen on.
1.45 ratchov 123: .Ar socket
124: cannot contain '/'.
1.39 jmc 125: Meaningful in server mode only.
1.16 ratchov 126: .It Fl u
1.21 jmc 127: Normally
128: .Nm
129: tries to automatically determine the optimal parameters for the audio device;
130: if this option is specified,
131: it will instead use the parameters specified by the
1.26 ratchov 132: .Fl Ccer
1.21 jmc 133: options.
1.30 ratchov 134: .It Fl v Ar volume
135: Software volume attenuation of the playback stream.
136: The value must be between 1 and 127,
1.31 jmc 137: corresponding to \-42dB and \-0dB attenuation.
1.33 ratchov 138: In server mode, clients inherit this parameter.
1.34 jmc 139: Reducing the volume in advance reduces a client's dynamic range,
140: but allows client volume to stay independent from the number
1.33 ratchov 141: of clients as long as their number is small enough.
1.34 jmc 142: A good compromise is to use \-4dB attenuation (12 volume units)
143: for each additional client expected
144: (115 if 2 clients are expected, 103 for 3 clients, and so on).
1.26 ratchov 145: .It Fl x Ar policy
1.22 ratchov 146: Action when the output stream cannot accept
1.26 ratchov 147: recorded data fast enough or the input stream
148: cannot provide data to play fast enough.
1.22 ratchov 149: If the policy
150: is
1.23 jmc 151: .Dq ignore
1.26 ratchov 152: (the default) then samples that cannot be written are discarded
153: and samples that cannot be read are replaced by silence.
1.22 ratchov 154: If the policy is
1.23 jmc 155: .Dq sync
1.26 ratchov 156: then recorded samples are discarded, but the same amount of silence will be written
1.22 ratchov 157: once the stream is unblocked, in order to reach the right position in time.
1.26 ratchov 158: Similarly silence is played, but the same amount of samples will be discarded
159: once the stream is unblocked.
1.22 ratchov 160: If the policy is
1.23 jmc 161: .Dq error
162: then the stream is closed permanently.
1.21 jmc 163: .El
164: .Pp
1.32 ratchov 165: If
166: .Nm
167: is sent
1.44 ratchov 168: .Dv SIGHUP ,
169: .Dv SIGINT
170: or
171: .Dv SIGTERM ,
1.32 ratchov 172: it terminates recording to files.
173: If sent
174: .Dv SIGUSR1
175: or
176: .Dv SIGUSR2 ,
177: it increases or decreases debug level, respectively.
178: .Pp
1.35 ratchov 179: Settings for input files
180: .Pq Fl i ,
181: output files
1.39 jmc 182: .Pq Fl o ,
1.35 ratchov 183: and sockets
184: .Pq Fl s
185: can be changed using the
186: .Fl Ccehrvx
1.16 ratchov 187: options.
1.21 jmc 188: The last
1.35 ratchov 189: .Fl Ccehrvx
1.23 jmc 190: options specified before an
1.35 ratchov 191: .Fl i ,
1.39 jmc 192: .Fl o ,
193: or
1.35 ratchov 194: .Fl s
1.41 jmc 195: are applied to the corresponding file.
1.21 jmc 196: .Pp
197: Settings for the audio device
198: can be changed using the
1.26 ratchov 199: .Fl Ccer
1.21 jmc 200: options.
201: They apply to the audio device only if the
202: .Fl u
203: option is given as well.
204: The last
1.26 ratchov 205: .Fl Ccer
1.21 jmc 206: option specified before an
1.16 ratchov 207: .Fl f
1.21 jmc 208: is applied to
209: .Ar device .
210: .Pp
211: If no audio device
212: .Pq Fl f
213: is specified but
214: .Fl u
215: is given anyway,
216: any
1.26 ratchov 217: .Fl Ccer
1.21 jmc 218: options specified before
1.41 jmc 219: .Fl ios
220: options are applied both to the corresponding file
1.21 jmc 221: and the default audio device;
222: if they are specified after
1.41 jmc 223: .Fl ios
1.21 jmc 224: options,
225: they will be applied only to the default audio device.
1.14 jmc 226: .Pp
1.20 jmc 227: File formats are specified using the
228: .Fl h
1.26 ratchov 229: option.
1.16 ratchov 230: The following file formats are supported:
231: .Bl -tag -width s32lexxx -offset -indent
232: .It raw
233: Headerless file.
1.17 jmc 234: This format is recommended since it has no limitations.
1.16 ratchov 235: .It wav
236: Microsoft WAVE file format.
237: There are limitations inherent to the file format itself:
238: not all encodings are supported,
239: file sizes are limited to 2GB,
1.17 jmc 240: and the file must support the
1.16 ratchov 241: .Xr lseek 2
1.17 jmc 242: operation (e.g. pipes do not support it).
1.16 ratchov 243: .It auto
244: Try to guess, depending on the file name.
1.9 millert 245: .El
246: .Pp
1.20 jmc 247: Encodings are specified using the
248: .Fl e
1.26 ratchov 249: option.
1.16 ratchov 250: The following encodings are supported:
251: .Pp
252: .Bl -tag -width s32lexxx -offset -indent -compact
253: .It s8
254: signed 8-bit
255: .It u8
256: unsigned 8-bit
257: .It s16le
258: signed 16-bit, little endian
259: .It u16le
260: unsigned 16-bit, little endian
261: .It s16be
262: signed 16-bit, big endian
263: .It u16be
264: unsigned 16-bit, big endian
265: .It s24le
266: signed 24-bit, stored in 4 bytes, little endian
267: .It u24le
268: unsigned 24-bit, stored in 4 bytes, little endian
269: .It s24be
270: signed 24-bit, stored in 4 bytes, big endian
271: .It u24be
272: unsigned 24-bit, stored in 4 bytes, big endian
273: .It s32le
274: signed 32-bit, little endian
275: .It u32le
276: unsigned 32-bit, little endian
277: .It s32be
278: signed 32-bit, big endian
279: .It u32be
280: unsigned 32-bit, big endian
281: .It s24le3
282: signed 24-bit, packed in 3 bytes, little endian
283: .It u24le3
284: unsigned 24-bit, packed in 3 bytes, big endian
285: .It s24be3
286: signed 24-bit, packed in 3 bytes, little endian
287: .It u24be3
288: unsigned 24-bit, packed in 3 bytes, big endian
289: .It s20le3
290: signed 20-bit, packed in 3 bytes, little endian
291: .It u20le3
292: unsigned 20-bit, packed in 3 bytes, big endian
293: .It s20be3
294: signed 20-bit, packed in 3 bytes, little endian
295: .It u20be3
296: unsigned 20-bit, packed in 3 bytes, big endian
297: .It s18le3
298: signed 18-bit, packed in 3 bytes, little endian
299: .It u18le3
300: unsigned 18-bit, packed in 3 bytes, big endian
301: .It s18be3
302: signed 18-bit, packed in 3 bytes, little endian
303: .It u18be3
304: unsigned 18-bit, packed in 3 bytes, big endian
305: .El
1.46 ! ratchov 306: .Sh SERVER MODE
! 307: .Nm
! 308: can be used in server mode
! 309: .Pq Fl l
! 310: to overcome hardware limitations and allow applications
! 311: to run on fixed sample rate devices or on devices
! 312: supporting only unusual encodings.
! 313: It is generally not desirable to have multiple
! 314: instances of
! 315: .Nm
! 316: running in server mode,
! 317: so it is good practice to start it thus:
! 318: .Bd -literal -offset indent
! 319: $ pgrep -x aucat || aucat -l
! 320: .Ed
! 321: .Pp
! 322: This also ensures privacy by preventing
! 323: other users from accessing the audio system.
! 324: On multi-user machines
! 325: .Nm
! 326: should be killed when no longer in use to make audio resources
! 327: available again to others:
! 328: .Bd -literal -offset indent
! 329: $ pkill -x aucat
! 330: .Ed
! 331: .Pp
! 332: Certain applications, such as synthesis software,
! 333: require a low latency audio setup.
! 334: To reduce the probability of buffer underruns or overruns,
! 335: the
! 336: .Xr renice 8
! 337: command can be used to give higher priority to
! 338: .Nm
! 339: process to.
! 340: Superuser privileges are required.
! 341: For example:
! 342: .Bd -literal -offset indent
! 343: $ aucat -b 3500 -l
! 344: $ sudo renice -n -20 -p `pgrep -x aucat`
! 345: .Ed
1.16 ratchov 346: .Sh LEGACY MODE
347: If neither
348: .Fl i
349: nor
350: .Fl o
1.17 jmc 351: are specified,
1.16 ratchov 352: .Nm
1.17 jmc 353: will run in legacy mode, and won't convert sample formats or sampling rates.
1.16 ratchov 354: In legacy mode, all options except
1.17 jmc 355: .Fl f
356: are ignored, and all other arguments are assumed to be names of files.
1.16 ratchov 357: In legacy mode
358: .Nm
359: reads files sequentially, and writes them to the specified device.
360: If a Sun .au header is detected it is skipped over and not copied to
361: the audio device.
362: .Nm
363: will attempt to play data from Sun .au files as monaural 8-bit ulaw
364: samples with a sampling frequency of 8000 Hz.
365: However,
366: .Nm
367: will not fail if the audio device cannot be configured for these
368: parameters.
369: If a Microsoft .wav header (RIFF) is detected it is interpreted
370: to select the right audio encoding for playback and the data chunk of the
371: file is copied to the audio device.
372: If the device does not support the encoding,
373: .Nm
374: will exit with an error.
1.9 millert 375: .Sh ENVIRONMENT
1.35 ratchov 376: .Bl -tag -width "AUDIODEVICE" -compact
1.22 ratchov 377: .It Ev AUCAT_DEBUG
378: The debug level:
379: may be a value between 0 and 4.
1.24 jmc 380: .It Ev AUDIODEVICE
381: The audio device to use.
1.9 millert 382: .El
1.16 ratchov 383: .Sh EXAMPLES
384: The following will mix and play two stereo streams,
385: the first at 48kHz and the second at 44.1kHz:
386: .Bd -literal -offset indent
387: $ aucat -r 48000 -i file1.raw -r 44100 -i file2.raw
388: .Ed
389: .Pp
390: The following will record channels 2 and 3 into one stereo file and
391: channels 6 and 7 into another stereo file using a 96kHz sampling rate for
392: both:
393: .Bd -literal -offset indent
1.26 ratchov 394: $ aucat -r 96000 -C 2:3 -o file1.raw -C 6:7 -o file2.raw
1.42 ratchov 395: .Ed
396: .Pp
1.43 jmc 397: The following will split a stereo file into two mono files:
1.42 ratchov 398: .Bd -literal -offset indent
399: $ aucat -n -i stereo.wav -C 0:0 -o left.wav -C 1:1 -o right.wav
1.16 ratchov 400: .Ed
401: .Pp
1.35 ratchov 402: The following will start
403: .Nm
1.40 jmc 404: in server mode using default parameters, but will create an
1.35 ratchov 405: additional socket for output to channels 2:3 only (rear speakers
1.39 jmc 406: on most cards):
1.35 ratchov 407: .Bd -literal -offset indent
1.45 ratchov 408: $ aucat -l -s default -c 2:3 -s rear
1.35 ratchov 409: .Ed
410: .Pp
411: The following will start
412: .Nm
1.39 jmc 413: in server mode creating the default socket with low volume and
414: an additional socket for high volume output:
1.35 ratchov 415: .Bd -literal -offset indent
1.45 ratchov 416: $ aucat -l -v 65 -s default -v 127 -s max
1.16 ratchov 417: .Ed
1.2 kstailey 418: .Sh SEE ALSO
1.12 jmc 419: .Xr audioctl 1 ,
1.17 jmc 420: .Xr cdio 1 ,
1.9 millert 421: .Xr mixerctl 1 ,
1.2 kstailey 422: .Xr audio 4
1.16 ratchov 423: .Sh BUGS
424: The
1.1 kstailey 425: .Nm
1.16 ratchov 426: utility assumes non-blocking I/O for input and output streams.
427: It will not work reliably on files that may block
428: (ordinary files block, pipes don't).
429: .Pp
430: Resampling is low quality; down-sampling especially should be avoided
431: when recording.
432: .Pp
433: Processing is done using 16-bit arithmetic,
434: thus samples with more than 16 bits are rounded.
1.17 jmc 435: 16 bits (i.e. 97dB dynamic) are largely enough for most applications though.
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