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post #16 of 662 (permalink) Old 2008-04-19, 11:44 AM
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the reason why there is no EPG, according to my contact at CIII (have yet to hear from my contact at CHCH) is the same reason that CIII doesn't have it, right now "Calgary Master" is not passing it down the pipe...
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post #17 of 662 (permalink) Old 2008-04-19, 01:28 PM
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So that explains many of the problems with the three stations. PSIP is not an easy thing to implement, as many of you remember the trouble CFTO-DT had for over a year when they went live.

Hopefully the Calgary Master Control folks are able to get in to work, what with the big snow storm that's supposed to hit there today!



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post #18 of 662 (permalink) Old 2008-04-19, 02:53 PM
 
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Engineering Calgary Global

Well I just got off the phone with Engineering Calgary Global and they tell me thier transmission is good and they know Global Vancouver is having transmitter troubles.
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post #19 of 662 (permalink) Old 2008-04-19, 03:02 PM
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Thanks Dan! Did you get a chance to ask them about CIII-DT and CHCH-DT PSIP troubles?



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post #20 of 662 (permalink) Old 2008-04-19, 03:05 PM
 
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no my main concern was tracking down a reason for this here vancouver problem. They are very helpful at the Calgary office very cheery and friendly too.
Further to the answer I did not see the alebowgm post until after the call sorry guys next time I guess

Last edited by danbcman; 2008-04-19 at 05:06 PM.
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post #21 of 662 (permalink) Old 2008-04-22, 02:46 PM
 
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Smile called calgary again

I will try and include all that I asked in a very long conversation regarding CIII and CHCH and CHAN here in Vancouver.

PSIP is handled at the actual station after it gets the stream from Calgary.

As it was put to me in simple terms other than a little wrapping done by Calgary the stream is not added to.

To further understand that: due to bandwidth there is no room for them in Calgary to add all the PSIP etc so that is why it is handled at each station.

For us here is Vancouver it remains in the hands of the station to address the packaging of there stream. I did give them in Calgary all the info I could about the data stream as my software read it. The greatest surprize was 99.9% was MPEG - 2 null packets?

As I am a guy with an antenna and not an engenneer I am unable to ask more direct formal questions but again the staff at Calgary very friendly and cheerfull and helpfull.
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post #22 of 662 (permalink) Old 2008-04-25, 12:40 PM
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Info on the Global DTV Startups and PSIP

It seems I was mistaken about Tandberg having a direct role in the recent CIII-DT and CHCH-DT launches. Those new digital stations are definitely using Tandberg equipment amongst other brands, but the actual digital transmitter setup work is being done by Larcan, the prime contractor. Larcan is a Canadian company out of Mississauga, so they obviously know the situation in Toronto and Hamilton before, during, and after the digital stations are started.

http://www.larcan.com/home/default.aspx

Part of the PSIP issues happening today in Toronto, Hamilton, and Vancouver have to do with the Global staff technicians having to learn to use the Tandberg PSIP tool from scratch, cold turkey. I don't envy that effort because PSIP is a real rats nest, but I know they'll do fine once they get more time on that system.

The Master Control centre in Calgary pipes the signal to the local digital stations over fibre land lines, who receive it on a Tandberg Transport Stream Processor box that they use to locally process the signal (overlays, etc.). That Tandberg box requires PSIP to be added using Tandberg's own proprietary tool. The finished product signal is fed into the local ATSC exciter for transmission.

Global staffers: we're on your side so hopefully our feedback in these forums will help with the implementation.



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post #23 of 662 (permalink) Old 2008-04-26, 01:38 PM
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Just a reminder: for more info on understanding PSIP data, see this thread:

http://www.digitalhome.ca/forum/showthread.php?t=49384



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post #24 of 662 (permalink) Old 2008-05-13, 03:24 PM
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Cool I think I found out which PSIP table is screwing up: MGT

I'm running MythTV on Linux to control 2 pcHDTV ATSC/NTSC cards. I could not get Global CHAN-DT 22.1 to automatically scan in even though command line tools locked onto the station and showed almost everything was fine. On further investigation the debugging output says that one of the mandatory PSIP tables is not working properly:

MGT = Master Guide Table = failure

Without that Master Guide Table it doesn't matter that all the other tables appear fine on my system. I think the MGT table issue is what Global should focus on now.
Quote:
The MGT provides a detailed description of all of the other tables in the system - which tables are present, the PIDs on which they are transmitted and the size in bytes of each table. This lets the receiver allocate memory appropriately before it actually starts parsing the tables (and also means that it knows which tables to look for). Why is this useful? As any experienced software developer will tell you, programming an embedded system can sometimes be a complicated matter of juggling memory - not allocating too much (which wastes memory that the rest of the system may need), but not allocating too little either (which then forces you to allocate more, and copy data around and generally waste time that could be spent doing more productive things).

By providing this information, the MGT gives the receiver a helping hand to parse the SI data as efficiently as possible.
http://www.interactivetvweb.org/tuto.../mgt-stt.shtml



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post #25 of 662 (permalink) Old 2008-05-13, 04:37 PM
 
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Another MythTV user here. I can't even get a command line tool lock (using azap and scan) on CHAN-DT with my HVR-1800; which concerns me. Stampeder, can you please tell me how you enabled debugging? I know that the signal is fine, because another computer with a HVR-950 feeding off the same antenna sees CHAN-DT with no problems.
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post #26 of 662 (permalink) Old 2008-05-13, 06:29 PM
 
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chan MGT

stampeder not having one may be even a bigger problem
email sent with MGT observation you made.
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post #27 of 662 (permalink) Old 2008-05-13, 08:35 PM
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Cool MythTV Channel Tuning Debugging (CHAN-DT Missing MGT)

In MythTV when you tune to a digital ATSC OTA channel with the on-screen display active you see the channel number, its name, the program title, the signal strength, the BER of the station (error rate in the signal), the SNR (signal to noise ratio) and a series of code letters in upper and lower case that have meaning for diagnosing problems. If the code letters are upper case that means things are good, lower case means that there is a problem, and an underscore means no data.

What tipped me off to Global's missing MGT data is that CBUT-DT (CBC) and CIVT-DT (CTV) both show "LAMGV", while CHAN-DT shows "LAM_V", so I looked it up and the missing G means that there is no MGT table present but everything else is there. I never saw that before because I could not get CHAN-DT entered by automatic scan so it was impossible to tune to it and see the output. Only after manually entering the station into the database (using PHPMyAdmin) and restarting the mythbackend could I tune the mythfrontend to CHAN-DT to see the on screen guide and read those debug letters.

Here's the official MythTV explanation:
Quote:
23.22 What do the letters mean when I change channels?

These letters let you know what's going on with the backend as it tries to tune to a channel.

Lower case = seen

Upper Case = seen & good

* l/L = Lock : This could be seen by PVR-250/BTTV users
* a/A = PAT : Any recording transmitted in MPEG
* m/M = PMT : Any recording transmitted in MPEG
* g/G = MGT : ATSC only
* v/V = VCT : ATSC only
http://www.mythtv.org/docs/mythtv-HOWTO.html#toc23.22

You can see in the TSReader output from other digital stations posted earlier in the CHAN-DT 22.1 thread that PAT is the Program Association Table, PMT means Program Map Table(s), and VCT means Virtual Channel Table. CHAN-DT has those just fine, but like Dan says, not having a Master Guide Table is a big problem!



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post #28 of 662 (permalink) Old 2008-05-13, 08:35 PM
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jbr439, it looks like you have the dvb-apps package loaded but I also run some apps that came with the pcHDTV cards (dtvscan, dtvsignal, dtvsnr, etc.) so they won't work on your card, I don't think. Using dtvsignal on the command line, the # hash mark changes to a $ dollar sign when a lock is made.

http://pchdtv.com/downloads.html (look for dvb-atsc-tools-1.0.7)

If you try those tools and they work on your HVR cards let me know.



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post #29 of 662 (permalink) Old 2008-05-14, 12:45 AM
 
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Quote:
Originally Posted by stampeder View Post
Only after manually entering the station into the database (using PHPMyAdmin) and restarting the mythbackend could I tune the mythfrontend to CHAN-DT to see the on screen guide and read those debug letters.
Dude, I salute your mysql-fu! Wouldn't have thought of doing that. Might give it a try when I get some time, but I don't expect much as the MythTV scan shows "no signal" for 22, whereas you were seeing some complaint about no tables, I believe. It seems odd that my HVR-1800 sees no inkling of CHAN-DT
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post #30 of 662 (permalink) Old 2008-05-14, 12:51 AM
 
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Quote:
Originally Posted by stampeder View Post
jbr439, it looks like you have the dvb-apps package loaded but I also run some apps that came with the pcHDTV cards (dtvscan, dtvsignal, dtvsnr, etc.) so they won't work on your card, I don't think. Using dtvsignal on the command line, the # hash mark changes to a $ dollar sign when a lock is made.

http://pchdtv.com/downloads.html (look for dvb-atsc-tools-1.0.7)

If you try those tools and they work on your HVR cards let me know.
That's correct. dtvscan and dtvsignal don't work with my HVR-1800, I need to use the dvb-utils (that's the package name in Debian) commands. Oddly enough, dtvscan and dtvsignal do work with my HVR-950. Go figure.
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