Difference between revisions of "Squeezeslave on the core"

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(Modify /etc/rc.local)
(Select Device)
 
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[[Category: Tutorials]]
 
[[Category: Tutorials]]
 +
[[Category:Audio]]
 
{| align="right"
 
{| align="right"
 
   | __TOC__
 
   | __TOC__
 
   |}
 
   |}
 +
==Whats does it do?==
 +
Squeezeslave basically makes it possible to add additional 'virtual' Squeezeboxes to your Core or MD's just by adding additional sound-cards. Each Squeezeslave/Sound-card combo uses about 4-5% CPU on an ATOM/Ion based MD. We have tested an ATOM/Ion based MD running 3 x Squeezeslave/Sound-Card combo's while playing a ripped DVD from the Core without any problems at all. Using Squeezeslave/Sound-Card combo's makes it possible to have several independent audio outputs from your Core or from an MD allowing you to use the 2nd Zone of your Surround Amp for example to provide audio to an adjoining room eg a bathroom or maybe a kitchen. All of this expands the options you have when designing your system, gives you enormous additional flexibility to locate additional audio sources where you need them, and reduces the energy footprint of your system at the same time (in comparison to adding additional physical Squeezeboxes).
 +
 
==Squeezeslave Setup==
 
==Squeezeslave Setup==
Here's how to setup squeezeslave to run on the core.  It's fairly straight forward.  One small issue is that because squeezeslave uses the OSS interface, you will need a separate sound card for each instance of squeezeslave you want to run.
+
Here's how to setup squeezeslave to run on your core or in fact any of your MD's.  It's fairly straight forward but currently requires manual config/install of each Squeezeslave - I'm working on making this something you can just configure from Web Admin simply and quickly.  One small issue is that because squeezeslave uses the OSS interface, you will need a separate sound card for each instance of squeezeslave you want to run.
===Needed depends===
+
 
 +
==Hardware Supported==
 +
The Startech Virtual 7.1 USB Audio Adapter (model No. ICUSBAUD107) works fine. This tiny USB Stick style adapter works perfectly under 7.10, 9.10 & 10.04. No installation...just plug it in and its ready a few secs later. Only stereo out jack and Mic input jack.
 +
 
 +
Many other brands of USB Audio adapter will probably work too. Please add your experiences with other working hardware here too.
 +
 
 +
Under LinuxMCE 0810 it may be necessary to downgrade Alsa in order for the device to appear (in 'aplay -l' or 'squeezeslave -L'). Be aware that downgrading alsa will remove audio over hdmi capabilities on the affected computer.
 +
 
 +
===Setting Up Squeezeslave on your Core or MD's===
 +
If you want to setup Squeezeslave on your Core then either open Konsole session from the KDE Desktop or ssh in from another machine and sudo yourself. If you want to set up Squeezeslave on an MD then ssh into your Core and then use;
 +
 
 +
ssh moonNNN (**where NNN is the ID number of the MD you want to ssh into.)
 +
 
 +
You can find the ID of your MD from the Web Admin page at Wizard->Devices->Media Directors and the ID is the number with a '#' in front of it at the top of each MD section. Now follow the instructions below for each MD you want to add Squeezeslave too.
 +
 
 +
===Needed Dependencies===
 
System libraries needed are subversion and libasound2-dev
 
System libraries needed are subversion and libasound2-dev
 
   sudo apt-get install subversion
 
   sudo apt-get install subversion
 
   sudo apt-get install libasound2-dev
 
   sudo apt-get install libasound2-dev
 +
Since squeezeslave is only updating the display versions of their makefiles also needed for building
 +
  sudo apt-get install libncurses5-dev
 +
  sudo apt-get install liblircclient-dev
 +
 +
===Squeezeslave is available in the debs===
 +
Easiest for anybody will be
 +
  sudo apt-get install squeezeslave
 +
This will install squeezeslave in the right directory for you to use. If you want to build it yourself follow the next steps.
 +
 
===Typical build===
 
===Typical build===
 
   svn checkout http://squeezeslave.googlecode.com/svn/squeezeslave/trunk/squeezeslave
 
   svn checkout http://squeezeslave.googlecode.com/svn/squeezeslave/trunk/squeezeslave
 
   cd squeezeslave
 
   cd squeezeslave
   make -f deprecated/makefile.linux26-alsa realclean
+
   make -f makefile.linux26-alsa-display realclean
   make -f deprecated/makefile.linux26-alsa
+
   make -f makefile.linux26-alsa-display
 +
 
 
===Or Download Source / look at the squeezeslave wiki===
 
===Or Download Source / look at the squeezeslave wiki===
Download a version of [http://sourceforge.net/project/showfiles.php?group_id=105169 Squeezeslave].  I'm running the latest version which was 0.9-143
+
Download a version of [http://sourceforge.net/project/showfiles.php?group_id=105169 Squeezeslave].  I'm running the latest version which was 0.9-173
  
 
Look at the slimdevices wiki for the latest options and install instructions http://wiki.slimdevices.com/index.php/SqueezeSlave
 
Look at the slimdevices wiki for the latest options and install instructions http://wiki.slimdevices.com/index.php/SqueezeSlave
 +
 
===Installing===  
 
===Installing===  
*You'll want to put it somewhere in your path.
+
*You'll want to put it somewhere in your path. (This is already done if you did the apt-get install method)
 
*There will be a file in the /bin directory called squeezeslave (there might be something added to this to represent the version you build, just rename the file to squeezeslave and copy to your wanted directory
 
*There will be a file in the /bin directory called squeezeslave (there might be something added to this to represent the version you build, just rename the file to squeezeslave and copy to your wanted directory
*Example: /usr/local/bin
+
*Example: /usr/bin
 
====Modify /etc/rc.local====
 
====Modify /etc/rc.local====
 
Next add the following to /etc/rc.local
 
Next add the following to /etc/rc.local
  /usr/local/bin/squeezeslave -o4 192.168.80.1 -m00:00:00:00:00:01 -r5 -M/var/log/squeezeslave.log
 
  
* the IP address should be the IP address of your Core.
+
If your setting up Squeezeslave on your Core then use;
 +
  /usr/bin/squeezeslave -o4 -m00:00:00:00:00:01 -r5 -M/var/log/squeezeslave.log
 +
 
 +
If your setting up Squeezeslave on one of your MD's then use;
 +
  /usr/bin/squeezeslave -o4 192.168.80.1 -m00:00:00:00:00:01 -r5 -M/var/log/squeezeslave.log
 +
 
 +
* the IP address should be the IP address of your Core (**Only needed if your running Squeezeslave on MD's**).
 
* the MAC address can be whatever you want, it just needs to be the same as the device created in linux mce
 
* the MAC address can be whatever you want, it just needs to be the same as the device created in linux mce
* the -o option specifies which OSS output device ie /dev/dsp1 (check with "squeezeslave -L" for available devices then use '-oN' where 'N' is the number next to your output device)
+
* the -o option specifies which output device ie /dev/dsp1 (check with "squeezeslave -L" for available devices then use '-oN' where 'N' is the number next to your output device)
 
See example output using 'squeezeslave -L' below;
 
See example output using 'squeezeslave -L' below;
  
squeezeslave -L
+
<pre>Output devices:
Output devices:
+
   0: (ALSA) SB Live! Value [CT4832]: ADC Capture/Standard PCM Playback (hw:0,0) (11/46)
   0: HDA NVidia: ALC1200 Analog (hw:0,0)
+
   2: (ALSA) SB Live! Value [CT4832]: Multichannel Capture/PT Playback (hw:0,2) (10/42)
   1: HDA NVidia: ALC1200 Digital (hw:0,1)
+
  3: (ALSA) SB Live! Value [CT4832]: Multichannel Playback (hw:0,3) (10/42)
   4: C-Media USB Audio Device   : USB Audio (hw:1,0)
+
   4: (ALSA) USB Audio Device: USB Audio (hw:1,0) (10/42)
   5: front
+
   5: (ALSA) front (11/46)
   6: surround40
+
   6: (ALSA) rear (11/46)
   7: surround51
+
   7: (ALSA) center_lfe (11/46)
   8: surround71
+
   8: (ALSA) surround40 (11/46)
   9: iec958
+
   9: (ALSA) surround41 (11/46)
  10: spdif
+
  10: (ALSA) surround50 (11/46)
  12: hdmi_playback
+
11: (ALSA) surround51 (11/46)
  13: asym_hdmi
+
  12: (ALSA) iec958 (10/42)
  14: asym_analog
+
  13: (ALSA) spdif (10/42)
  *16: default
+
  14: (ALSA) spdif_playback (11/46)
I am using the No.4 device in the output above and therefore would use '-o4' switch when using the squeezeslave command.
+
15: (ALSA) asym_spdif (11/46)
 +
17: (ALSA) asym_analog (42/46)
 +
  18: (ALSA) usb_analog (42/46)
 +
19: (ALSA) dmix (42/42)
 +
*20: (ALSA) default (42/46)</pre>
 +
 
 +
 
 +
I am using the No.18 device in the output above and therefore would use '-o18' switch when using the squeezeslave command.
  
 
* the -r option tells squeezeslave to keep retrying to connect to the server, useful if the server is not running yet.
 
* the -r option tells squeezeslave to keep retrying to connect to the server, useful if the server is not running yet.
 
* the -M option makes it run as a Daemon and creates log
 
* the -M option makes it run as a Daemon and creates log
 +
 +
====Fixing sample rate issues====
 +
Squeezeslave only likes the 44.1 kHz sample rate. Anything lower will sounds like the Smurfs, anything higher will sound "slow". This is fixed by converting the source stream to something squeezeslave can cope with.
 +
 +
You need to edit the <i>/etc/squeezeboxserver/convert.conf</i> file so it has these lines in it:
 +
 +
  mp3 flc squeezeslave *
 +
  [sox] -q -t mp3 $FILE$ -t flac -C 0 -r 44100 -
 +
  aac flc squeezeslave *
 +
  [faad] -q -w -f 1 $FILE$ | [flac] -cs --totally-silent --compression-level-0 --ignore-chunk-sizes - | [sox] -q -t flac - -t flac -C 0 -b 16 -r 44100 -
 +
 +
The aac to flc conversion could be shorter, but sox has a problem with '-t wav' with the output of faad and outputs an empty stream, and flac won't actually resample the stream when the --sample-rate=44100 parameter is given to it.
 +
 +
More conversions might be necessary as new stations are found to be problematic, but the strategy is the same: Convert to 'flac', resample to 44100 Hz.
 +
 +
You'll have to restart Squeezebox Server (Logitech Media Server) for the change to take effect.
  
 
===Setting Up Alsamixer===
 
===Setting Up Alsamixer===
Line 57: Line 115:
 
===Setting Up LinuxMCE===
 
===Setting Up LinuxMCE===
  
Next step, manually add the squeezeslave to linuxmce as a squeezebox using the mac address you gave it.
+
Next step, manually add the squeezeslave to linuxmce as a squeezebox using the mac address you gave it. The squeezebox player can be assigned to a room/entertainment area without an MD, in fact this would be a typical installation.
  
 
====Select Device====
 
====Select Device====
* Select '''Device->A/V Equipment'''
+
* Select '''Wizard->Devices->A/V Equipment''' and press 'Add device' on the bottom of the page.
* Select SqueezeBox Player from the dropdown options
+
* In the Device Template dropdown select 'SqueezeBox Player' (template #58) and press 'Pick device template'.
* Assign it to a room and entertainment area.
+
* Assign it to a room in the left dropdown box (-select room-, make sure you select a room that does not yet have a MD in it!), put the MAC of the squeezeslave in the MAC entry field and press update.  
 
* Regen your orbiters and reload the router.
 
* Regen your orbiters and reload the router.
  
 
Restart the core to make sure it's starting automatically, to run it manually just run the line made in the rc.local
 
Restart the core to make sure it's starting automatically, to run it manually just run the line made in the rc.local
  
   /usr/local/bin/squeezeslave -o5 -m 00:00:00:00:00:01 -r5 -M/var/log/squeezeslave.log
+
   /usr/bin/squeezeslave -o5 -m 00:00:00:00:00:01 -r5 -M/var/log/squeezeslave.log
  
 
* Check with ps if it is running:
 
* Check with ps if it is running:
 
   ps aux | grep squeezeslave
 
   ps aux | grep squeezeslave
 
**Example output:
 
**Example output:
  root    11502  0.0  0.8  51484  8812 ?        SLl  Apr07  0:33 /usr/local/bin/squeezeslave -05 -m00:00:00:00:00:02 -r5 -M/var/log/squeezeslave
+
  root    11502  0.0  0.8  51484  8812 ?        SLl  Apr07  0:33 /usr/bin/squeezeslave -05 -m00:00:00:00:00:02 -r5 -M/var/log/squeezeslave
  
 
That should do it.
 
That should do it.
  
  
use /usr/local/bin/squeezeslave -L for available audio devices
+
use /usr/bin/squeezeslave -L for available audio devices
  
use /usr/local/bin/squeezeslave -h for a list of options (see below)
+
use /usr/bin/squeezeslave -h for a list of options (see below)
  
<pre>/usr/local/bin/squeezeslave -h
+
<pre>/usr/bin/squeezeslave -h
 
squeezeslave 0.9-143
 
squeezeslave 0.9-143
 
compile flags: linux portaudio:1485 debug signals daemon
 
compile flags: linux portaudio:1485 debug signals daemon
Line 171: Line 229:
 
                                   slimaudio_output
 
                                   slimaudio_output
 
                                   slimaudio_output_v</pre>
 
                                   slimaudio_output_v</pre>
 +
 +
==Troubleshooting==
 +
 +
If you use a USB audio card and squeezeslave gives you an error, try the following
 +
 +
First of all make sure you are running the latest version.
 +
 +
Edit your /etc/asound.conf and add the following
 +
 +
<pre>pcm.usb_analog {
 +
        type asym
 +
        playback.pcm "plug:dmix:1"
 +
        capture.pcm "plughw:1"
 +
}</pre>
 +
 +
After this restart alsa
 +
 +
  /etc/init.d/alsa-utils restart
 +
 +
check your alsamixer to make sure pcm is unmuted and on a good level
 +
 +
Try squeezeslave again
 +
== Information from other places ==
 +
The slimdevices forum has a nice [http://forums.slimdevices.com/showthread.php?86253-Poor-Man-s-Multiroom-Audio post] on how to setup multiple Squeezeslave zones with a single soundcard.
 +
 +
In case the above link does not work anymore, there is a [http://deb.linuxmce.org/PoorMansMultiroomAudio.pdf PDF] output of said forum entry available.

Latest revision as of 15:44, 16 January 2013

Whats does it do?

Squeezeslave basically makes it possible to add additional 'virtual' Squeezeboxes to your Core or MD's just by adding additional sound-cards. Each Squeezeslave/Sound-card combo uses about 4-5% CPU on an ATOM/Ion based MD. We have tested an ATOM/Ion based MD running 3 x Squeezeslave/Sound-Card combo's while playing a ripped DVD from the Core without any problems at all. Using Squeezeslave/Sound-Card combo's makes it possible to have several independent audio outputs from your Core or from an MD allowing you to use the 2nd Zone of your Surround Amp for example to provide audio to an adjoining room eg a bathroom or maybe a kitchen. All of this expands the options you have when designing your system, gives you enormous additional flexibility to locate additional audio sources where you need them, and reduces the energy footprint of your system at the same time (in comparison to adding additional physical Squeezeboxes).

Squeezeslave Setup

Here's how to setup squeezeslave to run on your core or in fact any of your MD's. It's fairly straight forward but currently requires manual config/install of each Squeezeslave - I'm working on making this something you can just configure from Web Admin simply and quickly. One small issue is that because squeezeslave uses the OSS interface, you will need a separate sound card for each instance of squeezeslave you want to run.

Hardware Supported

The Startech Virtual 7.1 USB Audio Adapter (model No. ICUSBAUD107) works fine. This tiny USB Stick style adapter works perfectly under 7.10, 9.10 & 10.04. No installation...just plug it in and its ready a few secs later. Only stereo out jack and Mic input jack.

Many other brands of USB Audio adapter will probably work too. Please add your experiences with other working hardware here too.

Under LinuxMCE 0810 it may be necessary to downgrade Alsa in order for the device to appear (in 'aplay -l' or 'squeezeslave -L'). Be aware that downgrading alsa will remove audio over hdmi capabilities on the affected computer.

Setting Up Squeezeslave on your Core or MD's

If you want to setup Squeezeslave on your Core then either open Konsole session from the KDE Desktop or ssh in from another machine and sudo yourself. If you want to set up Squeezeslave on an MD then ssh into your Core and then use;

ssh moonNNN (**where NNN is the ID number of the MD you want to ssh into.)

You can find the ID of your MD from the Web Admin page at Wizard->Devices->Media Directors and the ID is the number with a '#' in front of it at the top of each MD section. Now follow the instructions below for each MD you want to add Squeezeslave too.

Needed Dependencies

System libraries needed are subversion and libasound2-dev

 sudo apt-get install subversion
 sudo apt-get install libasound2-dev

Since squeezeslave is only updating the display versions of their makefiles also needed for building

 sudo apt-get install libncurses5-dev
 sudo apt-get install liblircclient-dev

Squeezeslave is available in the debs

Easiest for anybody will be

 sudo apt-get install squeezeslave

This will install squeezeslave in the right directory for you to use. If you want to build it yourself follow the next steps.

Typical build

 svn checkout http://squeezeslave.googlecode.com/svn/squeezeslave/trunk/squeezeslave
 cd squeezeslave
 make -f makefile.linux26-alsa-display realclean
 make -f makefile.linux26-alsa-display

Or Download Source / look at the squeezeslave wiki

Download a version of Squeezeslave. I'm running the latest version which was 0.9-173

Look at the slimdevices wiki for the latest options and install instructions http://wiki.slimdevices.com/index.php/SqueezeSlave

Installing

  • You'll want to put it somewhere in your path. (This is already done if you did the apt-get install method)
  • There will be a file in the /bin directory called squeezeslave (there might be something added to this to represent the version you build, just rename the file to squeezeslave and copy to your wanted directory
  • Example: /usr/bin

Modify /etc/rc.local

Next add the following to /etc/rc.local

If your setting up Squeezeslave on your Core then use;

 /usr/bin/squeezeslave -o4 -m00:00:00:00:00:01 -r5 -M/var/log/squeezeslave.log

If your setting up Squeezeslave on one of your MD's then use;

 /usr/bin/squeezeslave -o4 192.168.80.1 -m00:00:00:00:00:01 -r5 -M/var/log/squeezeslave.log
  • the IP address should be the IP address of your Core (**Only needed if your running Squeezeslave on MD's**).
  • the MAC address can be whatever you want, it just needs to be the same as the device created in linux mce
  • the -o option specifies which output device ie /dev/dsp1 (check with "squeezeslave -L" for available devices then use '-oN' where 'N' is the number next to your output device)

See example output using 'squeezeslave -L' below;

Output devices:
  0: (ALSA) SB Live! Value [CT4832]: ADC Capture/Standard PCM Playback (hw:0,0) (11/46)
  2: (ALSA) SB Live! Value [CT4832]: Multichannel Capture/PT Playback (hw:0,2) (10/42)
  3: (ALSA) SB Live! Value [CT4832]: Multichannel Playback (hw:0,3) (10/42)
  4: (ALSA) USB Audio Device: USB Audio (hw:1,0) (10/42)
  5: (ALSA) front (11/46)
  6: (ALSA) rear (11/46)
  7: (ALSA) center_lfe (11/46)
  8: (ALSA) surround40 (11/46)
  9: (ALSA) surround41 (11/46)
 10: (ALSA) surround50 (11/46)
 11: (ALSA) surround51 (11/46)
 12: (ALSA) iec958 (10/42)
 13: (ALSA) spdif (10/42)
 14: (ALSA) spdif_playback (11/46)
 15: (ALSA) asym_spdif (11/46)
 17: (ALSA) asym_analog (42/46)
 18: (ALSA) usb_analog (42/46)
 19: (ALSA) dmix (42/42)
*20: (ALSA) default (42/46)


I am using the No.18 device in the output above and therefore would use '-o18' switch when using the squeezeslave command.

  • the -r option tells squeezeslave to keep retrying to connect to the server, useful if the server is not running yet.
  • the -M option makes it run as a Daemon and creates log

Fixing sample rate issues

Squeezeslave only likes the 44.1 kHz sample rate. Anything lower will sounds like the Smurfs, anything higher will sound "slow". This is fixed by converting the source stream to something squeezeslave can cope with.

You need to edit the /etc/squeezeboxserver/convert.conf file so it has these lines in it:

 mp3 flc squeezeslave *
 	[sox] -q -t mp3 $FILE$ -t flac -C 0 -r 44100 -
 aac flc squeezeslave *
 	[faad] -q -w -f 1 $FILE$ | [flac] -cs --totally-silent --compression-level-0 --ignore-chunk-sizes - | [sox] -q -t flac - -t flac -C 0 -b 16 -r 44100 -

The aac to flc conversion could be shorter, but sox has a problem with '-t wav' with the output of faad and outputs an empty stream, and flac won't actually resample the stream when the --sample-rate=44100 parameter is given to it.

More conversions might be necessary as new stations are found to be problematic, but the strategy is the same: Convert to 'flac', resample to 44100 Hz.

You'll have to restart Squeezebox Server (Logitech Media Server) for the change to take effect.

Setting Up Alsamixer

Next make sure all the volume levels in the mixer (alsamixer) are set correctly

 alsamixer

Make sure that the settings are as desired and save (Esc button)

Setting Up LinuxMCE

Next step, manually add the squeezeslave to linuxmce as a squeezebox using the mac address you gave it. The squeezebox player can be assigned to a room/entertainment area without an MD, in fact this would be a typical installation.

Select Device

  • Select Wizard->Devices->A/V Equipment and press 'Add device' on the bottom of the page.
  • In the Device Template dropdown select 'SqueezeBox Player' (template #58) and press 'Pick device template'.
  • Assign it to a room in the left dropdown box (-select room-, make sure you select a room that does not yet have a MD in it!), put the MAC of the squeezeslave in the MAC entry field and press update.
  • Regen your orbiters and reload the router.

Restart the core to make sure it's starting automatically, to run it manually just run the line made in the rc.local

 /usr/bin/squeezeslave -o5 -m 00:00:00:00:00:01 -r5 -M/var/log/squeezeslave.log
  • Check with ps if it is running:
 ps aux | grep squeezeslave
    • Example output:
root     11502  0.0  0.8  51484  8812 ?        SLl  Apr07   0:33 /usr/bin/squeezeslave -05 -m00:00:00:00:00:02 -r5 -M/var/log/squeezeslave

That should do it.


use /usr/bin/squeezeslave -L for available audio devices

use /usr/bin/squeezeslave -h for a list of options (see below)

/usr/bin/squeezeslave -h
squeezeslave 0.9-143
compile flags: linux portaudio:1485 debug signals daemon

Squeezeslave is licensed free of charge. There is NO WARRANTY for
the program. This program is provided "as is" without warranty of
any kind, either expressed or implied, including, but not limited
to, the implied warranties of merchantability and fitness for a
particular purpose.  The entire risk as to the quality and
performance of the program is with you.  Should the program prove
defective, you assume the cost of all necessary servicing, repair
or correction.

Copyright (c) 2004-2007 Richard Titmuss,
              2008-2010 Duane Paddock.

squeezeslave [options] [<server address>]
The Squeezebox Server address defaults to 127.0.0.1.
Options:
-h, --help:                 Prints this message.
-a,                         Sets the amplitude of a high-frequency tone
--predelay_amplitude <val>: produced during the predelay (see --predelay).
                            The frequency is set at the source's sampling
                            rate/2 and the amplitude is in absolute value.
                            For 16-bit sources, the max is 32767, but values
                            below 10 are likely to work.  The goal is to
                            produce an inaudible signal that will cause DACs
                            to wake-up and lock before actual samples are
                            played out.  If the DAC locks using only silence,
                            do not use this option (it will default to 0).
-k, --keepalive <sec>:      Controls how frequently squeezeslave sends a
                            alive signal to SqueezeCenter.  6.5.x servers
                            need this to avoid dropping the player's
                            connection.  By default, the implementation
                            chooses the right value: 10s for a >=6.5.x server
                            and 0s for a <6.5.x server, which means no
                            keepalive.
-M, --daemonize <logfile>   Run squeezeslave as a daemon.
                            Messages written to specified file.
                            Not supported with lirc and display modes.
-L, --list                  List available audio devices and exit.
-m, --mac <mac_address>:    Sets the mac address for this instance.
                            Use the colon-separated notation.
                            The default is 00:00:00:00:00:01.
                            SqueezeCenter uses this value to distinguish
                            multiple instances, allowing per-player settings.
-o, --output <device_id>:   Sets the output device id.
                            The default id is 0.
                            The output device ids can be found with -L.
-P, --port <portnumber>:    Sets the SqueezeCenter port number.
                            The default port is 3483.
-p, --predelay <msec>:      Sets a delay before any playback is started.  This
                            is useful if the DAC used for output is slow to
                            wake-up/lock, causing the first few samples to be
                            dropped.
--retry                     Causes the program to retry connecting to
                            SqueezeCenter until it succeeds or is stopped using
                            SIGTERM or keyboard entry (see -s/--signal).
                            If the connection to SqueezeCenter is lost, the
                            program will poll it until it restarts.  --retry
                            enables retry with a 5 second delay between
                            attempts.
-r <sec>                    For a different retry interval use -r and the
                            desired interval in seconds. (ie. -r10)
                            A value is required for this option.
-s, --signal:               Ignored. Always uses SIGTERM to exit.
-V, --version:              Prints the squeezeslave version.
-v, --volume <sw|off>:      Enables/disables volume changes done by
                            SqueezeCenter during its operation, such as when
                            changing the volume through the web interface or
                            when applying replay gain.  Defaults to sw.
                                  sw:  volume changes performed in software.
                                  off: volume changes ignored.
-Y, --debuglog <logfile>:   Redirect debug output from stderr to <logfile>.
-d, --debug <trace_name>:   Turns on debug tracing for the specified level.
                            The option can be used multiple times to enable
                            multiple levels.
                            Available levels:
                                  all
                                  slimproto
                                  slimaudio
                                  slimaudio_buffer
                                  slimaudio_buffer_v
                                  slimaudio_decoder
                                  slimaudio_decoder_r
                                  slimaudio_decoder_v
                                  slimaudio_http
                                  slimaudio_http_v
                                  slimaudio_output
                                  slimaudio_output_v

Troubleshooting

If you use a USB audio card and squeezeslave gives you an error, try the following

First of all make sure you are running the latest version.

Edit your /etc/asound.conf and add the following

pcm.usb_analog {
        type asym
        playback.pcm "plug:dmix:1"
        capture.pcm "plughw:1"
}

After this restart alsa

 /etc/init.d/alsa-utils restart

check your alsamixer to make sure pcm is unmuted and on a good level

Try squeezeslave again

Information from other places

The slimdevices forum has a nice post on how to setup multiple Squeezeslave zones with a single soundcard.

In case the above link does not work anymore, there is a PDF output of said forum entry available.