Skype

Revision 13 as of 2006-06-16 10:46:25

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Skype Internet Telephony

  • With Skype software, you can talk over the internet using your computer. Skype uses decentralized peer-to-peer technologies, so your calls do not go through a central server, it uses its own proprietary communication protocol to achieve this. In addition, all communications are encrypted so others cannot listen in. The Skype software is free to use, but it is not free software; the source code is proprietary and not available for modification.

    General information about Skype is on [http://en.wikipedia.org/wiki/Skype Wikipedia]. The official Skype website is http://www.skype.com. SkypeEthics gives information on why some users choose not to use Skype, and suggests alternatives, including ["Ekiga"] and [http://www.wengophone.com Wengophone].

The Problem

  • There are a few different aspects to the problem:
    1. Skype is not available in any Ubuntu software repository, and therefore cannot be installed with Ubuntu's package management software (such as Synaptic and apt-get).

    2. On some systems, the Skype application can only be used for one call each time it is run due to an issue with GNOME's Enlightened Sound Daemon (ESD).

The Solution

Installing Skype

  1. Add the skype repository*: deb http://download.skype.com/linux/repos/debian/ stable non-free

  2. Reload or update the package information
  3. Install the skype package. (*) To add the repository in Ubuntu 6.06, choose System - Administration - Software Properties - Installation Media - Add - Custom and enter the above line.

Running Skype

  • To start Skype, choose Applications->Internet->Skype. It usually takes a minute or two for Skype to get started, and you will think that nothing is happening, so be patient.

    When the Skype window finally opens, sign up (if necessary) and log in to your Skype account. Test your configuration by selecting the Echo / Sound Test Service contact (if not there already, add contact echo123) and clicking on the large green button at the bottom of the Skype window. If the connection is made and you hear a voice, your sound configuration is fine. If you cannot hear a voice, see the troubleshooting section below.

Troubleshooting Skype

  • If you are having audio problems, first check to make sure that sound is working on your system and that your microphone and speaker volume levels are high enough. If that does not work, then try changing the Skype audio device, and finally, if all else fails, modify your ESD configuration.

Audio Problems

1. Volume Levels

  1. Test that output is working with the Sound Preferences dialog. Choose System->Preferences->Sound.

  2. Test that microphone input is working with the Sound Recorder application. Choose Applications->Sound & Video->Sound Recorder.

  3. Ensure that your audio output and microphone input channels are not muted by choosing Applications->Sound & Video->Volume Control.

2. Skype Audio Device

  • If your audio levels are properly configured and you can hear audio in Skype but your contacts cannot hear your input, you may need to change Skype's input device. From the Skype menu, choose Tools->Options and select Hand/Headsets in the dialog that opens. Experiment with different Calls selections, if they are available.

3. ESD Configuration

  • Note: for Hoary/Breezy only. This is the already the default configuration in Ubuntu 6.06 (Dapper). A problem with the GNOME ESD (Enlightened Sound Daemon) server may cause issues with Skype for some users. If Skype is unable to make or recieve calls and continuously crashes, then a small change to the ESD configuration may help. Run:

      sudo gedit /etc/esound/esd.conf
    and change the line:
      auto_spawn=0
    to:
      auto_spawn=1
    Log out and back in to restart ESD, and test Skype again as above. It is likely that this solution will only work if Skype is the only application using audio. You will not be able to play music while using Skype, and you will not be able to use Skype while playing music.

    For more setup information, see the skype website article [http://www.skype.com/help/guides/soundsetup_linux.html Skype Sound and Audio Set-Up - PC Running Linux].

4. ALSA Configuration

  • Enabling ALSA gives you the choice to workaround some Skype issues: The present Skype Linux release (1.2.0.18) uses OSS sound, which means it allows only one application to access sound device. On some systems, OSS is not even used by default, which means you won't be able to select the OSS sound device (/dev/dsp) at all, because it does not exist. Worse off, it has a bug that makes Skype unusable after a call. Sometimes a few calls can be made, before it happens, but later only solution is to restart Skype. Technically it seems that Skype "forgets" to close the sound device before trying to open it again and therefore locks up. This seems to happen when you are the first to hang up and not when the other party hangs up first, so a workaround is to just wait at the end of a call and let the other party finish first.

    To avoid these issues, you can use ALSA instead of ESD. First, follow the guidelines found in [http://www.ubuntuforums.org/showthread.php?t=32063]. Then follow up with [http://juljas.net/linux/skype/]. Good luck!

    Note that the above forum post howto is for Hoary/Breezy. This should, according to [http://www.ubuntuforums.org/showpost.php?p=1143531&postcount=1089 mdz's post], not be an issue in Ubuntu 6.06 (Dapper).

4.1 Another possible solution for software mixing

gedit ~.asoundrc
  • Add the following text to it

pcm.skype {
   type asym
   playback.pcm "skypeout"
   capture.pcm "skypein"
}

pcm.skypein {
   # Convert from 8-bit unsigned mono (default format set by aoss when
   # /dev/dsp is opened) to 16-bit signed stereo (expected by dsnoop)
   #
   # We can't just use a "plug" plugin because although the open will
   # succeed, the buffer sizes will be wrong and we'll hear no sound at
   # all.
   type route
   slave {
      pcm "skypedsnoop"
      format S16_LE
   }
   ttable {
      0 {0 0.5}
      1 {0 0.5}
   }
}

pcm.skypeout {
   # Just pass this on to the system dmix
   type plug
   slave {
      pcm "dmix"
   }
}

pcm.skypedsnoop {
   type dsnoop
   ipc_key 1133
   slave {
      # "Magic" buffer values to get skype audio to work
      # If these are not set, opening /dev/dsp succeeds but no sound
      # will be heard. According to the alsa developers this is due
      # to skype abusing the OSS API.
      pcm "hw:0,0"
      period_size 256
      periods 16
      buffer_size 16384
   }
   bindings {
      0 0
   }
}
  • Create a skype launcher (in this example is going to be at your home directory).

gedit ~/skype.sh
  • add the following text

#/usr/bin/sh

ALSA_OSS_PCM_DEVICE="skype" aoss /usr/bin/skype --disable-dbus
  • Give skype.sh execution rights by browsing with nautilus over there, right click on the file, go to Properties, go to Permissions tab, and select "Execute" for the user. Double click on the file and you should be done.

Communication/SkypeOut Troubleshooting

  • If you encounter problems like Skype hanging (requiring killing the process through (System Tools->System Monitor) and if Skype is unable to dial out via SkypeOut, you should uninstall the 'gnomemeeting' package via the Package Manager.

Display configuration

  • Because Skype is a KDE application, Skype's typeface will appear very large on GNOME desktops. You can use either the kcontrol or the qt3-qtconfig package to configure the appearance of Skype and other KDE/QT applications. Of these two, the QT Configurator (qt3-qtconfig) has far fewer dependencies than kcontrol and may therefore be more convenient for people who mostly use non-KDE software. See also QtGnome for how to make Skype (and other Qt applications) look more like Gnome.

  • A quick fix, without installing any configuration packages at all, is to make a file qtrc in your $HOME/.qt directory, and put these two lines in it:

    •   [General]
        font=Bitstream Vera Sans Mono,9,-1,5,50,0,0,0,0,0
  • You can start QT Configurator with the "qtconfig" command. On the "Fonts" tab, choosing Font Family Sans Serif and Point Size 10 will give something that resembles Ubuntu's GNOME desktop.

  • If you install the kcontrol package, you may run it by entering kcontrol into the Applications/Run Application... prompt. Expand the Appearance & Themes menu and select Fonts. Press Adjust All Fonts and select Size. Lower this value to your preference (size 10 or 11 is usually satisfactory). Press OK and Apply and exit the KDE Control Center.

attachment:kcontrol.png

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