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modulations higher than 8psk on linux

modulations higher than 8psk on linux

Postby Zbabbir » Sun Sep 11, 2011 3:41 am

Hi,
The card works terrific on both QPSK and 8PSK - really terrific. BUT, while locking on 16apsk/32apsk, though the card does lock (FE_signal_lock on szap-s2) nothing else is working. dvbtraffic shows no pids and so does dvbsnoops. Basically anything but locking the signal on those higher modulations doesn't work. Any ideas?

Thanks,

Z.
Zbabbir
 
Posts: 3
Joined: Wed Jul 20, 2011 11:58 pm

Re: modulations higher than 8psk on linux

Postby SergioDanielG » Mon Sep 12, 2011 9:11 pm

Hi Zbabbir.

I was talking with "tbs" euro-support about blind scan for linux with tbs6925, and they give me a little tip to active it.
Reading your post, I think, maybe it's util for you because only need frequency and polarisation to lock signals.

I was working in a python script to do a simple blind scan but not end it yet.

Ok, look this:
You need recomplile TBS driver, from the source...
Open 'linux-tbs-drivers/linux/drivers/media/dvb/frontends/stv090x.c' with your prefered editor.
Search and found the function 'dvbfe_search stv090x_search()'
go to 'state->algo = STV090x_COLD_SEARCH;' line
and change to 'state->algo = STV090x_BLIND_SEARCH;'
In the same function, go to
if (state->srate > 10000000) {
dprintk(FE_DEBUG, 1, "Search range: 10 MHz");
state->search_range = 10000000;
} else {
dprintk(FE_DEBUG, 1, "Search range: 5 MHz");
state->search_range = 5000000;
}
and comment this lines and add 'state->search_range = 2000000;'

It like
--------------------------
/*
if (state->srate > 10000000) {
dprintk(FE_DEBUG, 1, "Search range: 10 MHz");
state->search_range = 10000000;
} else {
dprintk(FE_DEBUG, 1, "Search range: 5 MHz");
state->search_range = 5000000;
}
*/
state->search_range = 2000000;
--------------------------

Close and save the file, compile and install the driver, reboot and prove lock the TP with szap-s2, then with dvbsnoop prove obtain the pids y other data.
e.g.

$ szap-s2 -x -c yourChannelsFile "yourChannel"

With '-x' parameter, szap-s2 lock the TP and exit. Then

$ dvbsnoop -s pidscan

This is to obtain pids of the locked signal

$ dvbsnoop -n 1 - nph 0x10

This is to obtain network information table data.

Well, I hope that information will help you.

Best regards
SergioDanielG
 
Posts: 356
Joined: Tue May 31, 2011 3:53 am
Location: Tostado (SF) Argentina

Re: modulations higher than 8psk on linux

Postby Zbabbir » Wed Sep 14, 2011 5:41 pm

Hi,
Thanks for your reply.

I have tried what you suggested and although everything compiled, I'm still at the same situation. Let me explain myself again:

When I try and lock a qpsk/8psk signal (both dvb-s and s-2) everything works great. BUT, when I try to lock a 16apsk/32apsk signal the card itself locks on the signal but it does nothing besides. I mean, after I lock on a 32psk signal and the card says FE_HAS_LOCK (or something like that) dvbsnoop or dvbtraffic tells me nothing, they just hang. Btw, the same thing happens on windows when using tsreader with the new dll provided. The signal locks but tsreader shows no pids
Zbabbir
 
Posts: 3
Joined: Wed Jul 20, 2011 11:58 pm

Re: modulations higher than 8psk on linux

Postby SergioDanielG » Wed Sep 14, 2011 7:24 pm

Try lock a 16APSK/32ASPK signal but don't forget use "szap-s2 -x" to exit from szap-s2 when it's lock, and search pids with:
$ dvbsnoop -s pidscan

when you obtain pids, see the output of:
$ dvbsnoop -nph your_pid
"DSM-CC Datagram (IP network)"

Generaly (or all I'd found) in 16APSK/32ASPK signals it's only IP Networks and never are all pids active.

Best regards.
SergioDanielG
 
Posts: 356
Joined: Tue May 31, 2011 3:53 am
Location: Tostado (SF) Argentina

Re: modulations higher than 8psk on linux

Postby comfrey » Sun Dec 18, 2011 1:31 am

Thank you so much for your post SergioDanielG, I've been pulling my hair out trying to get the card to blindscan using the linux driver.
With the posted fix for the kernel I am now able to use a program called blindscan-s2 that chinesebob created.
http://rickcaylor.websitetoolbox.com/po ... ux-5168256
comfrey
 
Posts: 3
Joined: Sun Dec 18, 2011 1:23 am

Re: modulations higher than 8psk on linux

Postby SergioDanielG » Sun Dec 18, 2011 7:22 am

comfrey Wrote:Thank you so much for your post SergioDanielG, I've been pulling my hair out trying to get the card to blindscan using the linux driver.
With the posted fix for the kernel I am now able to use a program called blindscan-s2 that chinesebob created.
http://rickcaylor.websitetoolbox.com/po ... ux-5168256


Congratulations! It's a great notice.
Best regards
SergioDanielG
 
Posts: 356
Joined: Tue May 31, 2011 3:53 am
Location: Tostado (SF) Argentina

Re: modulations higher than 8psk on linux

Postby comfrey » Mon Dec 19, 2011 8:34 am

I am very close to having Fedora 16 configured for use with the TBS6925. I use the new and improved stv090x.c
But I have one question about dvbsnoop. I use the dvbsnoop -s pidscan and it works quite well. What does not work for me is the
dvbsnoop -s feinfo. The "current parameters" shows the Frequency Ok but it does not show the Current Symbol rate.?? It shows the Symbol rate that was used but not the changed value when doing the blind scan.

Is there an issue with the FE_GET_PROPERTY API

Any help would be appreciated.
comfrey
 
Posts: 3
Joined: Sun Dec 18, 2011 1:23 am

Re: modulations higher than 8psk on linux

Postby SergioDanielG » Mon Dec 19, 2011 7:07 pm

Current version of Linux driver for TBS 6925 doesn't implement fully 'get_frontend' extension (it's implemented fully on 6980/6981, 5921/6921/8921, 5922/6922/8922, 6928 though), therefore you can lock frequencies without knowing real parameters.
For this reason, dvbsnoop -s feinfo not show the current symbol rate.
Let's wait to implement it.

Best regasds.
SergioDanielG
 
Posts: 356
Joined: Tue May 31, 2011 3:53 am
Location: Tostado (SF) Argentina

Re: modulations higher than 8psk on linux

Postby comfrey » Tue Dec 20, 2011 12:06 pm

That is too bad, I look forward to when the driver has this capability. Thank you for the information.
comfrey
 
Posts: 3
Joined: Sun Dec 18, 2011 1:23 am

Re: modulations higher than 8psk on linux

Postby SergioDanielG » Tue Dec 20, 2011 7:03 pm

comfrey Wrote:That is too bad, I look forward to when the driver has this capability. Thank you for the information.

I understand they are working on it. Just have to wait.
Best regards.
SergioDanielG
 
Posts: 356
Joined: Tue May 31, 2011 3:53 am
Location: Tostado (SF) Argentina

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