[mythtv-users] Lirc commands in a shell script

[Alistair Grant]

On Mon, Sep 29, 2014 at 2:14 AM, Hika van den Hoven <hikavdh at gmail.com> wrote:
> Hoi Stephen,
>
> Sunday, September 28, 2014, 4:51:18 PM, you wrote:
>
>> On Sun, 28 Sep 2014 15:50:07 +0200, you wrote:
>
>>>
>>>
>>>> Hoi Stephen,
>>>
>>>> Sunday, September 28, 2014, 3:28:30 PM, you wrote:
>>>
>>>>> On Mon, 29 Sep 2014 02:21:21 +1300, you wrote:
>>>
>>>>>>On Sun, 28 Sep 2014 13:37:09 +0200, you wrote:
>>>>>>
>>>>>>>Hoi All ,
>>>>>>>
>>>>>>> I have Radio integrated in Myth with some adaptations as in the wiki.
>>>>>>> The radio command (ivtv-radio and aplay) itself runs as an
>>>>>>> independent service and I can select stations (with iradio, which can
>>>>>>> set the station on the screen or v4l2-ctl) either through a Mythmenu
>>>>>>> or through a shellscript. Also Volume (with amixer) I can control
>>>>>>> through that script.
>>>>>>> Through my remote I can turn it on and off, by starting/stopping the
>>>>>>> service. I would like to also be able to select stations and adjust
>>>>>>> volume through the remote. That way I do not need to turn on the
>>>>>>> screen. As I have seen suggested, it would be possible to receive
>>>>>>> Lirc commands in a shellscript, as long as of cause it's on the
>>>>>>> foreground. Does anybody know how to do that?
>>>>>>
>>>>>>Take a look at irexec - that runs things when triggered by a remote
>>>>>>button.  It could be used to send signals to your radio service.  I
>>>>>>have some test irexec setup in the MCE remote config I posted on my
>>>>>>web server a couple of days ago:
>>>>>>
>>>>>>   http://www.jsw.gen.nz/mythtv/mythbuntu-devinput-lirc.bz2
>>>>>>
>>>>>>Look at the end of the "mythtv" file that goes in /home/<your
>>>>>>mythfrontend user>/.lirc.  You can make an entire file of irexec setup
>>>>>>and add it to the /home/<your mythfrontend user>/.lircrc file to be
>>>>>>included in the lirc setup.  Whenever irexec is running, it will get
>>>>>>those commands.
>>>
>>>> Do you mean that I should in .lircrc set prog = irexec for the ones I
>>>> want to use in my script? I now run irexec for it is by default
>>>> present in the service script, but have all mythtv keys marked with
>>>> prog = mythtv. Then how do I catch them in the script? I guess I put a
>>>> while true; do loop around that to trigger when it receives a valid
>>>> command.
>
>> You can put script directly in the .lircrc entries for irexec, on the
>> config line, or you can call another program or an external script.
>> That code would need to somehow send signals to your radio service.
>
>> If you have entries in your .lircrc for different programs for the
>> same key, I am not sure if they are all run or only the first one that
>> is met is run.  You would need to check the lirc documentation.
>
>>>Or do they come in as regular keystrokes, so I can catch it with read.
>>>But then I need a following <Enter>.
>
>> No, the incoming keycodes from lirc are not passed on directly.  The
>> .lircrc entry matches a keycode from /usr/include/linux/input.h, and
>> for an ordinary program then sends out one or more characters (not
>> keycodes) to that program, as specified on the config line.  For
>> irexec, the characters it receives from the config line it takes as
>> some script code it must execute.  Mythfrontend interprets the
>> characters according to its jumppoints and keybindings database tables
>> and where it is in its screens (if it is in an alphanumeric entry
>> mode, for example).
>
>>>>> I should add that when I run mplayer from mythfrontend for a video
>>>>> file that mythfrontend can not play, only mplayer gets the remote
>>>>> buttons, not the underlying mythfrontend.  I do not know how that
>>>>> works, as if I run irexec in parallel with mythfronted, they both see
>>>>> the remote buttons.
>>>
>>>> I guess that is because then mythfrontend is not the front window.
>>>
>>>>> Another alternative for changing radio stations is to add them to
>>>>> MythTV as channels and use a channel change script to send the change
>>>>> station commands to your radio service.  I have that working for my FM
>>>>> radio scripts I use with my mothers PVR-150 FM tuner.
>>>
>>>> If looked at that some time ago, but couldn't get that working. Also
>>>> then I probably need my screen on to see what happens.
>
>> In my case, the FM frequency for the PVR-150 tuner is controlled via
>> the ivtv-radio command, so it is easy enough to get a channel change
>> script to issue the appropriate command based on the freqid value from
>> the channel table entry.  When I checked my code just now, I found I
>> am in fact doing that from a start recording event script, not a
>> channel change script.  I do not think the screen would need to be on
>> for that to work.  You would have to set up a key on the remote to go
>> to LiveTV mode (a jump table entry that works from everywhere), and
>> then you would just key in the channel number once in LiveTV.  I have
>> the radio stations as channel numbers 2001, 2002 and up to keep them
>> out of the way of any new TV channels.
>
>> I have my radio scripts on my web server if you want to have a look at
>> them:
>
>>   http://www.jsw.gen.nz/mythtv/event-start-recording.sh
>>   http://www.jsw.gen.nz/mythtv/event-finished-recording.sh
>
>> I am not sure if what I am doing works for LiveTV though - I only use
>> it for recording.  I know I have had problems with playing recordings
>> while they are still recording, but I do not think I have ever tried
>> with LiveTV.
>> _______________________________________________
>
> Thanks I'll look at your scripts. One suggestion though. Ones you have
> ivtv-radio with aplay running you better change channels through
> v4l2-ctl ( v4l2-ctl --device=</dev/radio?> --set-freq=<frequency> )
> since ivtv-radio needs to restart when you retune or if you daemonice
> then you get a new instance every time you run ivtv-radio.
> iradio is a wraparound ivtv-radio that can put tekst on screen through
> xosd and has some lirc support. Although I didn't really investigate
> the latter. Its documentation is scarce, mostly only that it exists.
>
> Also when again looking at irexec I found that the lirc package also
> contains irxevent which does translate to the actual key. I got it to
> place a '0' in a xterm. Now I have to test further, if I can get it to
> send or include <enter>. Else I can not catch it with read.

If you're familiar with python you could try receiving the lirc events
directly using the python-lirc package
(https://pypi.python.org/pypi/python-lirc/1.1), which would avoid the
problems of making sure the write xterm receives the events, line
ends, etc.

Disclaimer: I've never used this package, so don't know how well it works.

Cheers,
Alistair