[mythtv] OpenTV logical channel numbers

[Mark Spieth]

On 1/10/2020 4:11 PM, Stephen Worthington wrote:
> On Thu, 9 Jan 2020 23:35:04 +0100, you wrote:
>
>> Hi everybody,
>>
>> I've just added a patch from Mark Spieth to mythtv-setup that enables
>> getting the logical channel numbers from broadcasters such as Sky
>> (US/IT/NZ/AU), Dishnet(US) and others that use OpenTV.
>> Unfortunately I cannot receive an OpenTV channel but I am very
>> interested in how it works so if anybody can try it and report back
>> then yes please!
>>
>> I am also very interested in a full transport stream capture of these
>> signals for analysis purposes. It is now relatively easy to capture
>> the full stream, a.k.a. MPTS channel, with MythTV. One minute would be
>> great!
> I use MythTV to record from Sky New Zealand, and I get my OpenTV EPG
> from the Optus D1 12519 transponder, which has full EPG for all the
> Sky NZ channels on all transponders:
>
> https://www.lyngsat.com/Optus-D1.html
>
> I used dvbsnoop to capture 60 seconds from 12519 and I have put it on
> my web server:
>
> http://www.jsw.gen.nz/mythtv/SkyNZ_OpenTV_12519.ts
> (233,252,565 bytes)
>
> My web server runs on an ancient OS/2 setup, and only supports single
> threaded downloads, without any ability to restart failed downloads.
> And New Zealand is a long way from anywhere in terms of Internet ping
> times.  So I recommend using wget from a Linux box for large downloads
> from my server to get the best speed.
>
> Let me know if you would like more (or different) data captured from
> Sky NZ.  I am not certain that 60 seconds is enough to contain a full
> cycle of the EPG data.
>
> For my EPG grabbing, I am using a copy of tv_grab_dvb_plus that I have
> heavily modified to work with the current Sky NZ OpenTV data.  It
> works well enough to get the EPG for the channels I use on Sky NZ, but
> it is far from perfect and does not get correct data for all the SkyNZ
> channels.  It does see the LCNs (logical channel numbers), and I have
> modified it to provide the LCNs as a "number=" field in comments in he
> XML output.  Let me know if you would like a copy of the source.
>
> The original tv_grab_db_plus is here:
> https://sourceforge.net/projects/tvgrabeit/
>
> If you have managed to find proper documentation on the OpenTV EPG
> format, I would love to have a copy as that should allow me to make
> tv_grab_dvb_plus fully compatible.  At the moment, there are a number
> of descriptor types that it does not know how to decode.  I only have
> the basic DVB documentation to work from, nothing that is OpenTV
> specific.  The original authors of tv_grab_dvb_plus do seem to have
> had more than that.

Stephen,

I am one of the original authors and there is no doco other than other 
programs others wrote which we combined. Works for foxtelAU too but I 
have no use for it any more. Scaping is easier with webgrab++.

I can give you commit/admin privs if you would like to 
contribute/publish your changes. Some love would be appreciated for the 
project.

The sourceforge path is wrong because at the time we could not figure 
out how to rename it after we changed its name to tvgrabdvbplus.

I originally tried to port the opentv epg grabber to myth but lost 
interest so it was never done.

As for doc I believe you can buy it from the opentv foundation (whatever 
its name is) with a suitable NDA. I never did this.

Cheers

Mark