[mythtv-users] convoluted questiom

[Stephen Worthington]

On Mon, 27 Dec 2021 10:49:18 +0800, you wrote:

>> I just had a quick look at the Services API and it appears that there
>> is no API to start a recording in the manner that you do for Live TV,
>> where it starts immediately and continues until you stop it.  What is
>> needed is a call to GetRecordSchedule using the option that gets the
>> template rule that you want to use (eg 'Default'), then modify that to
>> set up a new recording rule, and call AddRecordSchedule to add it to
>> the schedule.  Then at the scheduled time, it will start recording. My
>> experience with manually starting and stopping scheduled recordings is
>> that if the starttime in the recording rule is in the past, and the
>> endtime is in the future, the recording can be restarted.  So I would
>> hope that setting the starttime to a little in the past and calling
>> AddRecordSchedule would immediately start recording.  But I would need
>> to test that.  If not, then a ReactivateRecording call would be needed
>> to get it to start recording.  All of which is a bit complicated for
>> what you want, but it looks doable.
>> 
>> However, the Sensoray 2263 is not likely to have MythTV support as a
>> capture device unless it has Linux V4L drivers.  The web page I found
>> says Linux is supported, but whether that means V4L support I am not
>> sure.  I suspect not.  So supporting it would likely mean also writing
>> an External Recorder program to interface between the Sensoray 2263
>> API and MythTV.  Something like what MythHDRecorder does with Silicon
>> Dust HDHR devices:
>> 
>> https://www.mythtv.org/wiki/Mythhdhrrecorder
>> 
>> That is a bit more work, but again likely doable.
>
>
>Stephen Thanks. The 2263 does have v4l2 support and does indeed work.

I have wanted for some time to have a quick way of starting manual
recordings so that I can test the performance of my MythTV boxes and
stress test them.  Then you asked about this and that prompted me to
think about exactly how it might be done.  So I have spent some time
over the last couple of days creating a "proof of concept" Python
program to do that, based on what might work for you.  I have put a
copy of my initial working version (0.1) on my web server here:

http://www.jsw.gen.nz/mythtv/start-recording.py

What it does is to create a manual recording rule with the start time
set to the current time and the end time set to six hours later.  The
recording is instantly started by mythbackend, and the recordid (index
of the recording rule in the record table) is reported back.  With the
current default settings, the title of the rule and the recording it
makes is set to "Dive Cam (Manual Record)".  There are command line
options to set the title and add an optional subtitle, and also to
select the MythTV channel to be recorded.  But you would want to set
the default values you need for all those things in the
"Configuration" section at the top of the code, so that simply running
"start-recording.py" from a command line will start a recording.  If
the Sensoray 2263 capture card in MythTV is set up with multirec
available, you can record to multiple different recordings at once, so
you could start a new recording before the previous one stops after
its default duration of 6 hours.

To install it download a copy to your /usr/local/bin directory and do
chmod +x on it.  Change the default settings in the "Configuration"
section - at the very least, you will need to set the CHANID value to
the chanid for the Sensoray 2263 device.  Then run it using the "-n"
dry run option.  You may get exceptions about missing Python modules -
install the correct modules and dry run it again until it reports that
the dry run worked.  If you can not get it to work, you can set the
DEBUG_OUTPUT option to True and send me a copy of what all the debug
code I have left in it says.

The way it creates its recording rules is to copy from a template rule
and then make changes to the copy.  It is currently set to use the
Default template.  So if you have specific settings you want in the
recording rules it creates, you can create a new template rule with
those settings, and change the TEMPLATE configuration option to make
it copy from that template.

It will run from any PC that has network access to the MythTV box -
just install a config.xml file that points back to the MythTV box, and
install the MythTV Python packages.

There are likely to be various ways it could still fail that it will
not handle well as I have not tried to test all the possible code
paths and error handling yet.  If you get anything like that, please
forward a copy of any exception messages.

I have not tried to write a corresponding "stop-recording.py" yet - to
stop any recording started by "start-recording.py", you will need to
go to the upcoming recordings list and stop it from there, then
manually delete the recording rule as well if you want to.  Old manual
recording rules set to do a single record should be cleaned up by
mythbackend automatically after their "endtime" elapses - it may only
happen when the housekeeper task does one of its 3-4 times a day runs
after the rule expires.  But I have not checked to see if that does
happen with recording rules created by "start-recording.py".

There is probably some redundant code - I just copied bits of my
existing Python MythTV code to patch this program together.  If it is
useful to you I can clean it up later, and incorporate anything
specific that you might need.