Thursday 29 April 2010

Dual Monitor VNC on Ubuntu - with scaling

To get dual-monitor remote desktop over VNC working withUbuntu, I had to install x11vnc. With the default VNC server, only half of my desktop would appear with the other half blacked out. Also, the whole two screen layout would not fit within my VNC client window.Ultimately this is the command I came up with the start the VNC server:

x11vnc -xinerama -xwarppointer -scale 3/4 -noxdamage -ncache 10

The first two arguments setup dual screen mode. The next one (-scale 3/4) scales the screen to 3/4 of it's original size (the scaling is done server-side). The -noxdamage argument prevented some annoying server errors that were appearing. And the -ncache 10 option enables client-side pixel caching, which speeds up things considerably.

References:
http://ubuntuforums.org/showthread.php?t=535574
http://ubuntuforums.org/archive/index.php/t-252888.html
https://help.ubuntu.com/community/VNC?action=show&redirect=VNCOverSSH

Friday 16 April 2010

openSuSE 11.2 sound on HP dv7t-1000 - ALSA, Pulseaudio, and JACK

It took a lot to get this setup. I made the mistake of installing PulseAudio, and had to uninstall it before my sound would work in the slightest. But even then, I had jerky sound. The solution was to make some edits to my /etc/modprobe.d/50-sound.conf so that it appears as follows:
options snd-hda-intel model=hp-m4 enable_msi=1
# u1Nb.Jqboh86TqAC:82801I (ICH9 Family) HD Audio Controller
alias snd-card-0 snd-hda-intel
After making these changes, and restarting my computer, the sound worked again. I could start JACK with Rosegarden with no troubles (after doing the standard realtime permissions fix).

Some links:
http://www.alsa-project.org/main/index.php/SoundcardTesting
http://en.opensuse.org/SDB:AudioTroubleshooting
http://en.opensuse.org/HCL/Laptops/HP#dv_7
http://en.opensuse.org/Alsa-update
http://en.opensuse.org/SDB:Intel-HDA_sound_problems
http://hg.alsa-project.org/alsa-kernel/raw-file/5082de4abb26/Documentation/ALSA-Configuration.txt
http://www.alsa-project.org/main/index.php/Matrix:Module-hda-intel
http://akoskm.blogspot.com/2009/01/laptop-extra-keys-howto.html
http://en.opensuse.org/Pulseaudio
http://pulseaudio.org/wiki/BrokenSoundDrivers

Wednesday 14 April 2010

ebay USB MIDI Interface on Ubuntu Linux (1a86:752d)

I recently bought a USB MIDI interface off ebay. It was just a generic, pretty cheap made-in-china kind of model, with a red, orange and green light. It lit up red when I plugged it into my (Linux) computer, but showed up in lsusb as "Unknown" device:
root@theta:~# lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 005 Device 003: ID 0461:0010 Primax Electronics, Ltd
Bus 005 Device 002: ID 045e:0040 Microsoft Corp. Wheel Mouse Optical
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 003: ID 046d:09b8 Logitech, Inc.
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 007 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 008 Device 004: ID 1a86:752d Unknown
Bus 008 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Turns out, even though it's listed as an unknown device, it still worked as a MIDI input. I just started up JACK Audio Server, Rosegarden, and ZynAddSubFx for an organ simulation. Then i plugged in the MIDI In and Out ports to my keyboard, hooked up the connections in JACK and it all worked!

Being USB of course, there was some delay, and for some peculiar reason no keys below Middle C would work for me. But it works well on Sibelius!

Wednesday 7 April 2010

openSuSE 11.2 as Active Directory PDC?

I'm looking at reinstalling my server (currently Ubuntu 8.04 LTS) with openSuSE 11.2. Does anyone know of some way that I can configure openSuSE as an Active Directory domain controller? I would like to configure Samba and LDAP with a GUI preferably, and automatically transfer any modifications I make to the client computers. I also need offline authentication.

I was looking at Novell eDirectory, and it appears to be exactly what I am looking for. Is there a tutorial available for how to setup eDirectory on openSuSE? By default it runs on Open Enterprise Server only.