modulations higher than 8psk on linux

[Zbabbir]

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.

[SergioDanielG]

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

[Zbabbir]

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

[SergioDanielG]

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.

[comfrey]

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

[SergioDanielG]

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

[comfrey]

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.

[SergioDanielG]

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.

[comfrey]

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

[SergioDanielG]

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.