man1/Alofi.1

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    Alofi(1)							     Alofi(1)

    NAME
      Alofi	- a network-transparent	audio server for LoFi

    SYNOPSIS

      The AF audio server is a network transparent	system developed at Digital
      CRL for using	LoFi audio hardware in a distributed environment.

    DESCRIPTION

      Alofi	is an AF server	with LoFi/DECaudio device dependent support.

    STARTING UP
      Alofi	[:portOffset] [options]	&

    OPTIONS

      -help

           Use the help switch to determine	device independent arguments.

      -device device

           Specifies the name of the LoFi audio device.  If	this switch is not
           used, the Alofi audio server will default to the	device specified by
           the AUDIO_DEVICE	environment variable or	the /dev/lofi device.  (In
           general,	/dev/lofi is a symbolic	link to	the /dev/lofi0 device special
           file.)

      -ukernel lodfile

           Specifies an alternate DSP56001 absolute	lodfile.  If ukernel is	not
           specified, the server checks for	the AF_UKERNEL environment variable.
           If neither the switch nor the AF_UKERNEL	environment is used, the
           server looks for	the path DIR/main.lod (Or DIR/mainteleport.lod in
           -teleport mode) where DIR is the	LODPATH	environment variable if	it
           exists, otherise	it is the config variable LODDIR.

      -pcoeff coeff_file

           Specifies an alternate set of X filter coefficients for the
           primary/phone CODEC.  coeff_file	should be an ASCII file	containing
           eight lines with	two bytes per line representing	the X filter coeffi-
           cients for the AMD79C30A	CODEC.	Here are the contents of an example
           file containing the default coefficients	used on	LoFi's telephone
           CODEC.

    	 94 0F
    	 C2 AC
    	 94 FF
    	 22 AB
    	 36 EA
    	 4A B2
    	 A4 E2
    	 BC BA

      -teleport

           When this switch	is specified, the operation of the hifi	parts of the
           server are customized to	work well with the Ariel Teleport DSP port to
           telephone interface.  In	this mode, device 2 is a 16 bit	mono path to
           Line 1 of the Teleport and device 3 is a	16 bit mono path to Line 2 of
           the Teleport.  On device	2, the passthrough mode	controls the "line"
           or "local" setting of the local telephone set.  Device 2	also provides
           two "inputs".  Input 0 connects the interface to	the telephone line,
           while Input 1 connects the device to the	Teleport local battery cir-
           cuit.  Along with -teleport, you	must specify "-mode ext" "-hrate xxx"
           and "-dspc xxx".

           The Teleport mode replaces the low two client data bits on output with
           inband signalling to the	Teleport.  On input, the low two bits are
           inband signalling from the Teleport, which are observed,	but not
           changed by the server.

      -nohifi

           Disables	HiFi support (devices 2, 3, and	4).

      -daa_gain {0,1}

           Sets the	state of the telephone DAA's gain control bit. Setting the
           bit to 1	(default) disables the power limiting circuitry	in the DAA.
           Setting the bit to 0 enables the	automatic power	limiter.

      -mode	{int,ext}

           Sets the	hi-fi operating	mode:  int selects the internal	stereo DAC
           (44.1 kHz, two-channel output).	ext selects an external	device con-
           nected to the DSP port.	NOTE:  make sure the switch on the back	of
           the distribution	box is set to match the	operating mode.	 Defaults to
           int.

      -hrate <#>

           Informs the server of the hi-fi sample rate (in samples per second).
           This option does	not set	the rate for the hi-fi hardware.  The inter-
           nal DAC runs at 44100 samples per second.  External devices may have
           fixed sample rates, be configurable with	panel switches,	or may be
           software	configurable (see the -dspc parameter below); consult the
           device's	manual for details.  Defaults to 44100.

      -dspc	<#>

           Specifies a 3-bit DSP port value	that sets the sample rate for some
           hi-fi devices; consult the device's manual for details.	Only valid
           when the	external operating mode	is selected.

    AUDIO DEVICES

      The Alofi audio server presents five audio devices to	client applications.
      These	audio devices are the 8KHz mu-law telephone CODEC, the 8KHz local
      audio	CODEC, left and	right stereo HiFi device, mono HiFi left channel dev-
      ice, and finally the mono HiFi right channel device.	These audio devices
      have device numbers of 0 to 4.  In Teleport mode, there are 4	devices, num-
      bered	0 to 3.

    CONNECTION NAME

      From the user's prospective, every AF	server has an audio connection of the
      form:

    			      hostname:portOffset

      This information is used by the application to determine how it should con-
      nect to the server.

      hostname
    	  The hostname specifies the name of the machine to which the audio
    	  device is physically connected.

      portOffset
    	  The portOffset is used to identify the audio server's	port on	host-
    	  name.	 For example, to simultaneously	run two	audio servers on a
    	  given	host, you might	select 0 or 1 for portOffset.

      If the connection name to an audio server is not specified, then the
      environment variables	AUDIOFILE or DISPLAY will be used.

    ACCESS CONTROL
      The sample server provides two types of access control:  an authorization
      protocol which provides a list of ``magic cookies'' clients can send to
      request access, and a	list of	hosts from which connections are always
      accepted.

    EXAMPLES

      Alofi	has been used with the following three devices:	the Ariel ProPort
      Model	656, the Ariel Teleport	Model 214, the Ariel DM-N Digital Microphone,
      and the Applied Speech Technologies A/D16.

      A "-mode ext"	option selects external	operation (disabling the DECaudio's
      built-in stereo DAC).	 The "-dspc #" option sets bits	on the DSP port	to
      set the external device's sample rate	in some	device specific	way.  The "-
      hrate	#" informs the server of the sample rate (the actual sample rate is
      usually set by the external device).

      Ariel	DM-N Digital Microphone	settings:

    	  5.5 kHz:	  Alofi	-mode ext -dspc	3 -hrate 5500
    	  11.02	kHz:	  Alofi	-mode ext -dspc	2 -hrate 11020
    	  22.05	kHz:	  Alofi	-mode ext -dspc	1 -hrate 22050
    	  44.1 kHz:	  Alofi	-mode ext -dspc	7 -hrate 44100

      Ariel	ProPort	Model 656 settings:

    	  8 kHz:	  Alofi	-mode ext -dspc	6 -hrate 8000
    	  11.025 kHz:	  Alofi	-mode ext -dspc	5 -hrate 11025
    	  16 kHz:	  Alofi	-mode ext -dspc	4 -hrate 16000
    	  32 kHz:	  Alofi	-mode ext -dspc	3 -hrate 32000
    	  44.1 kHz:	  Alofi	-mode ext -dspc	2 -hrate 44100
    	  48 kHz:	  Alofi	-mode ext -dspc	1 -hrate 48000

      Applied Speech Technologies, A/D16: (fixed single channel, 16	kHz input)

    	  16 kHz:	  Alofi	-mode ext -hrate 16000

      Ariel	Teleport Model 214 settings:

    	  7.2 KHz:	  Alofi	-teleport -mode	ext -dspc 2 -hrate 7200
    	  8.0 KHz:	  Alofi	-teleport -mode	ext -dspc 1 -hrate 8000
    	  9.6 KHz:	  Alofi	-teleport -mode	ext -dspc 0 -hrate 9600

    BUGS
      DECaudio's built-in DAC will not work	if there is an external	device
      plugged into the DSP port (regardless	of the switch setting).

      If you encounter a repeatable	bug, please submit a problem report to () and
      include the source code if possible.

    SEE ALSO

      AF(1), Aaxp(1), Amaxine(1), Alofi(1),	Ajv(1),	Amsb(1), Aj300(1), aplay(1),
      arecord(1), apass(1),	aset(1), abrowse(1), afft(1), ahost(1),	aphone(1),
      aprop(1), ahs(1), axset(1), xpow(1), afxctl(1), aname2num(1),	alsatoms(1),
      aevents(1), abob(1)

    COPYRIGHT

      See the COPYRIGHTS file.

      Copyright 1991-1994, Digital Equipment Corporation and the Massachusetts
      Institute of Technology.

    AUTHORS
      Digital Cambridge Research Lab