[mythtv-users] dtv_multiplex.transmission_mode data type with BBC QAM-256 DVB-T2 streams

[Nemo]

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Interesting. I don't use EIT, but I did have to go through similar convolutions to build the multiplex table.

Looking at the forum thread it does seem that we are seeing similar problems. I'll give the script a try to see if I can exactly reproduce what you're seeing - that won't be until at least Friday though unfortunately.


Sent from my Android phone with K-9 Mail. Please excuse my brevity.

Toric <toric at enuntia.net> wrote:

 

> The problem is that the card doesn't seem to switch very well between SD 

>& HD (or indeed sometimes between SD muxes). It seems however to work  
>better with mplayer if I have a channels.conf that says  
>TRANSMISSION_MODE_32K rather than TRANSMISSION_MODE_AUTO and it'd be  
>good to make a similar comparison in myth.  

 

I very new to this list so please point out any etiquette transgressions.

 

I am testing a Mythbuntu 11.10 install using the BlackGold BGT3650 card and the BlackGold version 1.0.0.791 binary drivers. I have an issue with channel switching that I have posted on ubuntuforums http://ubuntuforums.org/showthread.php?t=1916304 but also seems to fit very well with this myth-users thread.

 

I invite you to take a look to see whether it's on topic.

 

But regarding tuning, I too resorted to updating dtv_multiplex manually. But that was to ensure that the transport and net ids were set correctly, thus getting EIT to work.

 

I went through the scan/edit channels loop many times before deciding upon a working strategy which was to look up the (Crystal Palace) transmitter mux info and enter each one through "edit transports". Then do a scan for a "single existing transport" without selecting the "use other located transports" (that's not quite the right wording but Mythers will know the one I mean - won't you) for each of the manually entered transports. 

 

By doing it that way it did not get any "conflicting channels" found and all the channel numbers matched those on a real TV. My source is set to EIT only for program info. However, I was not getting any OTA program  information. I found a thread where someone had discovered that for DVB transmissions, Myth would not gather EIT info unless netid and transport id were available. Unfortunately the edit transport GUI does not allow entry of those two values and a scan on existing transports does not fill them in automatically, thus requiring the manual updates. I got the missing transport ids from a thread on avforums IIRC and the net ids all are the same. (I also set all the BBC channels to "commercial free" whilst I was in mysql.) With those changes in place, all the EIT info and most of the icons appeared without mythfilldatabase which  I avoid running because I had found on previous attempts that it would also have added some duplicate channels due to some of the names varying
slightly between the EIT and RT sources.

 

Subsequently, I found that I was getting some recordings of video/audio garbage from start to finish and on further investigation I found that it was sometimes happening on live tv. Diagnosing this problem is the subject of my mythbuntu thread.

 

I hope this is of interest to you all and if you have any thoughts about the garbage video/audio issue I would be delighted to hear them.

 

myth797: do you use BlackGold's own drivers?

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