Wayne D's Blog

I installed Centos 7 on an HP Stream which has too small of a drive to allow you to update Windows 10. Everything went well until I tried to connect to the network via wifi. The wifi connected but really didn't work. lspci shows that the machine uses a Realtek RTL8723BE PCIe Wireless Network Adapter.

Some Googling led me to https://askubuntu.com/questions/883673/rtl8723be-wifi-incredibly-weak on askubuntu.com. Running the following command as root and rebooting fixed the problem.
#sudo tee /etc/modprobe.d/rtl8723be.conf <<< "options rtl8723be ant_sel=1"

Recently I upgraded my kernel and ran into weak wifi again, I edited /etc/modprobe.d/rtl8273be.conf and changed ant_sel=1 to ant_sel=2 and everything was fine again.

After updating my media center I couldn't get the Yatse remote control app. on my android phone to work. After giving up and installing the official Kodi remote app. I did some looking around and realized that in Yatse host settings use event server was checked on the advanced tab. Unchecking that setting fixed the problem

Evidently the firewall on my media server was blocking that port which caused the remote to stop working when I upgraded my OS.

Created with one ls command, one vi command and the following two ffmpeg commands:

Save the names of the dashcam files to another file
ls *.avi > files

MOVI8642.avi
MOVI8644.avi
MOVI8645.avi
MOVI8646.avi
MOVI8647.avi
MOVI8648.avi
MOVI8649.avi

add the word file in front of each of the filenames so ffmeg can parse the input file
vi files
:1,$s/^/file /
ZZ (saves the file and exits)

file MOVI8642.avi
file MOVI8643.avi
file MOVI8644.avi
file MOVI8645.avi
file MOVI8646.avi
file MOVI8647.avi
file MOVI8648.avi
file MOVI8649.avi
file MOVI8650.avi
file MOVI8651.avi

Put the files together and speed them up
ffmpeg -f concat -i files -filter:v "setpts=0.0166*PTS" -an TtoOfast.mp4

Add music
ffmpeg -i TtoOfast.mp4 -i ~/Downloads/Curse\ of\ the\ Scarab.mp3 -codec copy -shortest TtoOfast_m.mp4

Trying to move a window up to click a button that's off the button because your screen is to small? Before Gnome 3 the Alt ley was the one to hold down while dragging the window. With Gnome 3 they key you need to use has changed to the Windows key which for some reason Gnome calls the Super key instead of the Windows key. On Centos 7 the firewall configuration GUI isn't shown in settings. It's the application that I needed to move up to adjust on my laptop as shown in the screenshot at the beginning of this post.

Enter the following command on your local machine (machine_A):
ssh user@remote_machine -L 5900:localhost:5900 "x11vnc -display :0 -noxdamage"
then run vncviewer and use localhost as the server to connect to and you should see the remote machine's screen.

To do it in the other direction if you use x11vnc to connect outwards.
At a console prompt on the local machine (Machine_A) enter: vncviewer --listen (listens on port 5500 by default)
At a console prompt on the remote machine enter: ssh user@Machine_A -L 5500:localhost:5500 -N
And finally on the remote machine: x11vnc -connect localhost -display :0
and you should see the remote machines screen.

If you have a machine on the internet and you want to get ssh access to a machine behind a firewall, you can set up a straight ssh tunnel. It's a variation of second method

On the machine you want to access (Machine_A) you enter:
ssh -R 5301:localhost:22 user@machine_B -N
and on Machine_B
ssh user@localhost -p 5301 and you should see a login prompt from Machine_A
if you set GatewayPorts yes in /etc/ssh/sshd_config on Machine_B and you have access to port 5301 on Machine_B. You can also access Machine_A from another Machine
with ssh Machine_B -p 5301