Tuning Parameters

[ceandra]

Sub:

Comcast keeps making changes that are messing up my tuning. Happened yesterday on Fox. I am using Clear Qam on an Aver M780 card. Fox is mapped by Comcast, normally, to channel 2.1, but is physically on channel 115, program 2.

In GBPVR, I have cut and pasted the entire tuning string into the source tuning parameter location. However, last night, during the Orange Bowl, it stopped working. My TV tuner maps over to the "2.1" named location, and also stopped working. However, the Aver software, crappy as it is, still tuned the program!

What I found by re-scanning just channel 115 is that all of the tuning parameters changed, then name was dropped, but the program was still 115.2. Therefore, my TV could not find it (no longer name-mapped), neither could pvrx2 (no longer proper tuning parameters), but Aver could (cannot see what they do, but presumably they just point to channel 115, program #2).

So, in the tuner setup, instead of listing all the tuning parameters, is there a way to simply specify physical channel 115, program #2? It seems whenever they mess things up, the channel and program remain in the right place, but the tuning parameters change. I have found the same on channel 125, which houses about a dozen SD channels. The program number stays correct, but the tuning parameters change. If I re-scan and cut and paste from the Cache file, all is good again for a month or two.

Here is the old tuning string:
T:115,2,1~P:2~V:33~A:35~PMT:32~N:>2.1 Kasa (000(AC3))

Here is the new tuning string last night:
T:115,115,1~P:2~V:49~A:52~PMT:32~PCR:49~N:>115.1 Unknown1 (000(AC3))

Here is the listing from SiliconDust:
Type Channel Program Call Sign Resolution Aspect
qam256 115 2 KASADT 1280x720p
16:9

[ceandra]

Bump

BTW, I am using version 1.1.5, Aver M780, EVGA Nvid 7800, 3.4GHz P4. Not that any of that makes a difference for this issue.

Is there somewhere in teh Wiki (I cannot find it) where all of the tuning parameters are explained?

Thanks
Chuck

[whurlston]

T:115,2,1 = Tune Request. The format is Physical Channel (115), Virtual Major (2.1), Virtual Minor (2.1)
P:2 = Program number
V:33 = Video stream PID number
A:35 = Audio stream PID number
PMT:32 = Program Map Table stream PID number
N:>2.1 Kasa (000(AC3)) = Name reported by the stream or physical channel, program number if not reported.


PMT and N parameters are not required. I do not believe the last two numbers in the T parameter are required either. I believe they can be "0" but I can't remember for sure.

[ceandra]

Thanks.

I presume this to mean I cannot just specify the physical channel and the program number, as in 115 and 2 in this case. I must know the V and A parameters? This is what appears to have changed. Some reason, the Aver software still found the programs after these changes at Comcast, but GBPVR and my TV could not.

[sub]

If you have <BDAAutoMapPids>true</BDAAutoMapPids> in config.xml, but have the P: set correctly, then it might auto correct the V/A pids. It works for DVB, but I've never tried it with ATSC.

[whurlston]

hmm.. I may play around with that. You know how I like to break things.

[ceandra]

Sub:

That sounds like the ticket. Do I have to have any A and V for it to start with, or should I just have T:115,115,1~P:2

[sub]

You do need some values, but they can be set to some bogus values like ~V:100~A:101

I get the feeling it wont work with ATSC though.

[ceandra]

I'll give it a shot and see what happens.

[ceandra]

It did not appear to work.

I changed the config.xml. Then added a dummy channel with various tuning parameters. Presumably, exiting config will cause a re-read of the config.xml, as I did not reboot. The correct tuning right now for FOX is:

T:115,115,1~P:2~V:49~A:52~PMT:32~PCR:49

I tried the following:


T:115,2,1~P:2~V:33~A:35~PMT:32
T:115,2,1~P:2~V:33~A:35
T:115,115,1~P:2~V:33~A:35~PMT:32
T:115,115,1~P:2~V:33~A:35~PMT:32~PCR:49

They all gave the No Signal display.

It would seem to be possible, given that programs such as TSreader can find all this information. Should I send you any logs from TSreader?

Obviously this would require a change to GBPVR, and perhaps it is not a big issue for most people. I don't know why Comcast would change the Audio and Video streams, but keep the program the same.

If this is a dead end for now, perhaps you could add it to the wish list for future version.

Thanks
Chuck