Wednesday, March 22, 2017

Fedora 24: Recording with Ardour, QJackCtl and Zoom 2g.1u Guitar Effects Pedal.

I assume that you have Ardour (I have version 5.5.0-1), JACK, QJackCtl already installed and Zoom correctly connected to your computer via USB.

[GUITAR]---INPUT[ZOOM]---USB---[PC]PHONES---AUX[AMP]PHONES---d(-_-)b
                OUTPUT-------------------------INPUT

First launch QJackCtl and configure the JACK server. Do not start the server yet. Click Setup... button.


From Settings tab select Advanced tab.
Select as an Input Device and choose the hw:CODEC USB Audio CODEC.


Launch the Ardour and select the following settings for the new session and click Start button. 


Once the Ardour is started check if the JACK is running and you see the connections. If JACK is not running click the Start button.


Click the Connect button and then Expand All. You may need to click Refresh too.


Add a new track(s).



Right click on the track and select Inputs... and Outputs... to configure the connections respectively.
Repeat the same for all other tracks you added and the Master track.

Track(s)


Master:

You can also configure Inputs... and Outputs... in the Mixer. 
Click the Mixer button in Ardour main window on the toolbar.
Click the "Track Name" in the Mixer for each track and select Inputs... and Outputs... to configure them.




You can start recording now.

Note: Of course, it is a very basic configuration to just get you started. I guess, it should work with any USB audio interface really. If you want to learn more please see the reference below.

Reference:



Saturday, October 1, 2016

Fedora 24: invisible mouse cursor after login to VM running on KVM.

Issue: In Fedora 24 after login into the VM running on a local host in KVM the mouse cursor becomes invisible.

Environment: 
Host
    - Fedora 24
    - kernel 4.7.4-200.fc24.x86_64
    - virt-manager-1.4.0-3.fc24.noarch
    - virt-viewer-4.0-1.fc24.x86_64
    - qemu-kvm-2.6.1-1.fc24.x86_64
VM
    - SUSE Linux Enterprise Server 12 SP1
    - kernel 3.12.49-11-default
    - video QXL / Spice
    - gnome-shell-3.10.4-40.1.x86_64

Solution:
I found that changing the screen resolution to a different value resolves the issue and mouse cursor becomes visible again.
To automate this workaround I wrote the following simple script named chres.sh:

     #!/bin/bash
     # Change the resolution
     XRANDR=`which xrandr`
     SCREEN="Virtual-0"
     $XRANDR --output $SCREEN --mode 1280x720
     sleep 1
     $XRANDR --output $SCREEN --mode 1280x800
     exit

I then created the autostart folder in ~/.config/ and added chres.sh to it and made it executable.
Finally, I created the following file in ~/.config/autostart/ named chres.desktop:

     [Desktop Entry]
     Name=chres
     GenericName=Changing resolution
     Comment=To change the resolution in Gnome session 
     Exec=/home/username/.config/autostart/chres.sh
     Terminal=true
     Type=Application
     X-GNOME-Autostart-enabled=true

Now when I login to Gnome session the chres.sh runs automatically changing quickly the resolution and resolving the issue, so the mouse cursor is immediately visible and available. 
If you have the same issue, you may need to check if the xrandr is installed in the same path and what is your default screen.


I hope this will help.

Thursday, September 24, 2015

Fedora 22 : Moving from Gnome to KDE/Plasma

I decided to give it a try again on my Fedora 22 laptop, since I am happily using KDE/Plasma on my openSUSE desktop and in my personal opinion even though Gnome is now a great new and fresh desktop, I truly believe that it is far too heavy for its minimalistic look and approach and is missing some simple and quite common desktop features, for instance standard window buttons like minimize, maximized, etc. Also there are couple of nice features which you need to add as extensions and https://extensions.gnome.org/ is still showing "Beta" on the home page, for ages now. The desktop modification options are at their minimum. Simply it takes to much effort in my opinion to make default Gnome on Fedora to make it work and look the way you may want, at least for me. This is not good for a modern desktop these days, I believe. It gives me the feeling that Fedora (with Gnome) although open source seem to be very much like vendor locked, at least out of the box, do not get me wrong. KDE/Plasma on the other side, although also quite fresh and killed systray we knew for so long, still is much more flexible out of the box, I think.

My Fedora 22 is a long running laptop after several upgrades, changes, etc. I actually do not remember when I reinstalled it fresh last time. I have to say, fedup was doing a great job every time.

The way I did it.

First, I installed KDE Plasma Workspaces group.

# dnf group list
# dnf group install "KDE Plasma Workspaces"

I restarted the machine and I was presented with gdm. I selected KDE (obviously) and logged in. So far, so good.

Then I decided to change the gdm to sddm.

# dnf install sddm
# systemctl status gdm.service
# systemctl disable gdm.service
# systemctl enable sddm.service
# reboot

After a reboot I could not login anymore. Neither my user password, nor root password worked.

I logged in on the second console (Ctrl+Alt+F2) as root and checked /var/log/messages. I found the following entries:

Sep 24 00:14:35 xxx kernel: audit: type=2300 audit(1443050075.602:649): pid=6160 uid=0 auid=500 ses
=4 subj=system_u:system_r:xdm_t:s0-s0:c0.c1023 msg='pam: default-context=unconfined_u:unconfined_r:unc
onfined_t:s0-s0:c0.c1023 selected-context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 exe="/
usr/libexec/sddm-helper" hostname=? addr=? terminal=:0 res=success'

Checking status of the sddm service also was returning some errors regarding PAM authentication problems and not being able to find the user.

I logged in on the second console as regular user , started X and changed the sddm settings from System Settings > Statup and Shutdown > Login Screen (SDDM). Rebooted the machine... and still the same problem and same errors.

I checked the /etc/sddm.conf only to find out that all the changes made in GUI were not saved there.
I manually then edited the file to look like this:

# cat /etc/sddm.conf
[Autologin]
Relogin=false
Session=
User=

[General]
NumLock=on
HaltCommand=
RebootCommand=

[Theme]
Current=breeze
CursorTheme=breeze_cursors

[Users]
MaximumUid=65000
MinimumUid=500

One of the main problems was that my user has the UID=500 and the default value for MinimumUid was 1000. Changing the value in GUI was not reflected in this config, so I changed it manually again.
After that I created a user's photo icon with the filename username.face.icon and format PNG image data, 62 x 63, 8-bit/color RGB, non-interlaced. I then copied it to /usr/share/sddm/faces/.
Finally, I restarted sddm service, logged out from the second console and restarted the laptop.
Now I was presented with my local user, selected Plasma and logged in without problem.

Maybe this will help you too. ;-)

P.S.
I did not remove Gnome. Why not to switch from time to time and see what is going on there? The same like with different distros. There is no better or worse, there is only different taste. I like blueberries, you like pears. ;-)