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IABSD.fr/src/usr.bin/aucat/aucat.1
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.\" $OpenBSD: aucat.1,v 1.123 2024/05/21 05:09:29 ratchov Exp $ .\" .\" Copyright (c) 2006 Alexandre Ratchov <alex@caoua.org> .\" .\" Permission to use, copy, modify, and distribute this software for any .\" purpose with or without fee is hereby granted, provided that the above .\" copyright notice and this permission notice appear in all copies. .\" .\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES .\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF .\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR .\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES .\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. .\" .Dd $Mdocdate: May 21 2024 $ .Dt AUCAT 1 .Os .Sh NAME .Nm aucat .Nd audio file manipulation tool .Sh SYNOPSIS .Nm aucat .Op Fl dn .Op Fl b Ar size .Op Fl c Ar channels .Op Fl e Ar enc .Op Fl f Ar device .Op Fl g Ar position .Op Fl h Ar fmt .Op Fl i Ar file .Op Fl m Ar min : Ns Ar max Ns / Ns Ar min : Ns Ar max .Op Fl o Ar file .Op Fl p Ar position .Op Fl q Ar port .Op Fl r Ar rate .Op Fl v Ar volume .Sh DESCRIPTION The .Nm utility can play, record, mix, and process audio files on the fly. During playback, .Nm reads audio data concurrently from all played files, mixes it and plays the result on the device. Similarly, it stores audio data recorded from the device into corresponding files. An .Em off-line mode could be used to process audio files without involving audio hardware. Processing includes: .Pp .Bl -bullet -offset indent -compact .It Change the sound encoding. .It Route the sound from one channel to another. .It Control the per-file playback volume. .El .Pp Finally, .Nm can accept MIDI messages usable for: .Pp .Bl -bullet -offset indent -compact .It Volume control. .It Start, stop and relocate playback and recording. .El .Pp The options are as follows: .Bl -tag -width Ds .It Fl b Ar size The buffer size of the audio device in frames. Default is 7680. .It Fl c Ar channels The audio file channels count. The default is 2, i.e. stereo. .It Fl d Increase log verbosity. .It Fl e Ar enc Encoding of the audio file. The default is .Va s24 . Encoding names use the following scheme: signedness .Po .Va s or .Va u .Pc followed by the precision in bits, the byte-order .Po .Va le or .Va be .Pc , the number of bytes per sample, and the alignment .Po .Va msb or .Va lsb .Pc . Only the signedness and the precision are mandatory. Examples: .Va u8 , s16le , s24le3 , s24le4lsb . .It Fl f Ar device Use this .Xr sndio 7 audio device. Device mode and parameters are determined from audio files. Default is .Pa default . .It Fl g Ar position Go to the given time position and start playback or recording there. This option is equivalent to an incoming MMC relocate message with the same position. The position is expressed as the number of samples (at device sample rate). .It Fl h Ar fmt Audio file type. The following file types are supported: .Pp .Bl -tag -width autoX -compact .It Cm raw Headerless file. .It Cm wav Microsoft WAV file format. .It Cm aiff Apple's audio interchange file format. .It Cm au Sun/NeXT audio file format. .It Cm auto Try to guess, depending on the file name. This is the default. .El .It Fl i Ar file Play this audio file. If the option argument is .Sq - then standard input will be used. .It Fl m Ar min : Ns Ar max Ns / Ns Ar min : Ns Ar max Map the given range of source channels into the given range of destination channels. .It Fl n Off-line mode. Read input files and store the result in the output files, processing them on the fly. This mode is useful to mix, demultiplex, resample or re-encode audio files off-line. It requires at least one input .Pq Fl i and one output .Pq Fl o . .It Fl o Ar file Record into this audio file. If the option argument is .Sq - then standard output will be used. .It Fl p Ar position Time offset where the beginning of the file belongs. The first sample of the file will be played or recorded when the device reaches the given position. The position is expressed as the number of samples (at device sample rate). .It Fl q Ar port Control audio device properties through this MIDI port. This includes per-stream volumes and the ability to synchronously start, stop and relocate audio files. .It Fl r Ar rate Sample rate in Hertz of the audio file. The default is .Cm 48000 . .It Fl v Ar volume Software volume attenuation of the file to play. The value must be between 1 and 127, corresponding to \-42dB and \-0dB attenuation in 1/3dB steps. The default is 127, i.e. no attenuation. .El .Pp On the command line, per-file parameters .Pq Fl cehmrv must precede the file definition .Pq Fl io . .Pp If .Nm is sent .Dv SIGHUP , .Dv SIGINT or .Dv SIGTERM , it terminates recording to files. .Sh MIDI CONTROL .Nm can be controlled through MIDI .Pq Fl q as follows: a MIDI channel is assigned to each stream, and the volume is changed using the standard volume controller (number 7). The master volume can be changed using the standard master volume system exclusive message. .Pp All audio files are controlled by the following MMC messages: .Pp .Bl -tag -width relocateX -offset indent -compact .It relocate All files are relocated to the requested time position. If it is beyond the end of a file, the file is temporarily disabled until a valid position is requested. .It start Playback and/or recording is started. .It stop Playback and/or recording is stopped and all files are rewound back to the starting position. .El .Pp MIDI control is intended to be used together with .Xr sndiod 8 . For instance, the following command will create two devices: the default .Va snd/default and a MMC-controlled one .Va snd/default.mmc : .Bd -literal -offset indent $ sndiod -r 48000 -z 480 -s default -t slave -s mmc .Ed .Pp Programs using .Va snd/default behave normally, while programs using .Va snd/mmc wait for the MMC start signal and start synchronously. Then, the following command will play a file on the .Va snd/mmc audio device, giving full control to MIDI software or hardware connected to the .Va midithru/0 MIDI port: .Bd -literal -offset indent $ aucat -f snd/mmc -q midithru/0 -i file.wav .Ed .Pp At this stage, .Nm will start, stop and relocate automatically following all user actions in the MIDI sequencer, assuming it's configured to transmit MMC on .Va midithru/0 and .Va snd/mmc . Furthermore, the MIDI sequencer could be configured to use the .Va snd/mmc port as MTC clock source, assured to be synchronous to playback of .Pa file.wav . .Sh EXAMPLES Mix and play two files while recording a third file: .Bd -literal -offset indent $ aucat -i file1.wav -i file2.wav -o file3.wav .Ed .Pp Record channels 2 and 3 into one stereo file and channels 6 and 7 into another stereo file using a 44.1kHz sampling rate for both: .Bd -literal -offset indent $ aucat -r 44100 -m 2:3/0:1 -o file1.wav -m 6:7/0:1 -o file2.wav .Ed .Pp Split a stereo file into two mono files: .Bd -literal -offset indent $ aucat -n -i stereo.wav -c 1 -m 0:0/0:0 -o left.wav \e -m 1:1/0:0 -o right.wav .Ed .Sh SEE ALSO .Xr cdio 1 , .Xr audio 4 , .Xr sndio 7 , .Xr audioctl 8 , .Xr mixerctl 8 , .Xr sndiod 8 .Sh BUGS Resampling is low quality. .Pp There are limitations inherent to the .Ar wav , .Ar aiff , and .Ar au file formats: not all encodings are supported, file sizes are limited to 2GB, and the files must support the .Xr lseek 2 operation (e.g. pipes do not support it).