[mythtv-users] FAQ about LIRC and Video...

Nick Morrott knowledgejunkie at gmail.com
Wed Feb 7 23:40:04 UTC 2007

On 07/02/07, david abbey <zam62 at yahoo.com> wrote:
> I have made my own IR serial receiver and have
> installed LIRC.  However, when I start LIRC and
> IRW/mode2, I get no response when pressing a remote
> control button.
> is there a way to deduce whether this is a remote
> issue, an LIRC issue, or an IR receiver issue?  Can I
> safely deduce that it is not a LIRC issue because IRW
> and mode2 get connected?  Does it make a difference on
> what remotes are being used; doe the IR/LIRC grab the
> button press regardless?

Homebrew serial IR receivers should pick up most/all IR remotes.
However, if you are wanting to test if the receiver is working, mode2
is the one to use. irw requires a valid /etc/lircd.conf file for your
remote to produce output. mode2 will let you know if a signal is being
received over the serial port.

Testing whether the remote is working can be achieved by looking at
the IR LED through a digital camera/camcorder (sensitive to IR light)
whilst pressing buttons.

If the receiver is being detected, the output in the lirc log output
should say something like:

Feb  7 12:43:38 marge kernel: lirc_serial: auto-detected active low receiver

You need to release the kernel's serial port driver from the serial
port using setserial before loading the lirc modules, and you should
have lirc_dev and lirc_serial modules loaded.

Finally, what LIRC devices do you have when the modules are loaded,
and which device is lircd being started with? There can be issues when
lircd is started with a missing /dev/lirc device when /dev/lirc0

> I have ripped a couple of my DVD's to play on my
> mythbox.  One of them plays fine and the other is
> choppy.  The only difference that I can see is that
> one VOB was 8Gb and the other only 4Gb. Does Gt
> rendering Vs OpenGl rendering matter while watching
> vids? Any info will be appreciated.


> Nvidia 5200 video card

With XvMC support and a 5200 card, your machine should be capable of
playing regular DVDs. Which video output method is your frontend
using? Are you deinterlacing output?

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