DVB-S2 won't tune unless modulation specified

[Muzer]

A number of applications (for example mplayer) have no way of specifying the modulation, yet this card won't tune a channel unless the modulation is specified.

I'm using the stock drivers in 2.6.38.

Is there a way to get the card to tune when no modulation is specified (another driver/whatever)?

[Muzer]

Just tried to install the official driver from this website, it seemed to break all V4L support in the kernel. I had to completely purge the kernel and reinstall it, then.

[SergioDanielG]

A number of applications (for example mplayer) have no way of specifying the modulation, yet this card won't tune a channel unless the modulation is specified.

I'm using the stock drivers in 2.6.38.

Is there a way to get the card to tune when no modulation is specified (another driver/whatever)?

No blind scan in TBS8920, it can not know parameters if not specificated.
The best way to use TBS6920 is VDR or Mythtv. But you need scan frequencies first. scan-s2 to vdr, mythtv-setup to mythtv.

Best regards.

[Muzer]

A number of applications (for example mplayer) have no way of specifying the modulation, yet this card won't tune a channel unless the modulation is specified.

I'm using the stock drivers in 2.6.38.

Is there a way to get the card to tune when no modulation is specified (another driver/whatever)?

No blind scan in TBS8920, it can not know parameters if not specificated.
The best way to use TBS6920 is VDR or Mythtv. But you need scan frequencies first. scan-s2 to vdr, mythtv-setup to mythtv.

Best regards.

I suppose, then, the only way would be for me to modify the driver so that if automatic modulation is specified, it tries one then the other. Do you think this would be possible? (I haven't yet looked at the code).

[SergioDanielG]

I suppose, then, the only way would be for me to modify the driver so that if automatic modulation is specified, it tries one then the other. Do you think this would be possible? (I haven't yet looked at the code).

I think it's not a good idea because the card require other parameters to tune and lock: frequency, polarization, simbol rate, fec, rolloff and modulation.
The "standard" parameters are: simbol rate: 27500, fec 3/4, rolloff 35 and modulation QPSK
If you try (via driver) other modulation, you need try other parameter too...
Modulations: 2, minimal (QPSK, 8PSK).
Simbol rate: 10 to 30 Msps, almost 20 steps.
Rolloff: 3 (20, 25, 35)
Fec: 8 supported by the card (1/2, 3/5, 2/3, 3/4, 4/5, 5/6, 8/9, 9/10 )

2 x 20 x 3 x 8 = 960 trys x 200ms = 192 seconds = 3.2 minutes to try all posibilites. It's a lot of time if you like zapping...

Best regards

[Muzer]

But symbol rate, frequency and polarisation are always specified by the software; rolloff I think it works without, not sure whether or not it works without FEC. Modulation is the only one I noticed it definitely requires (but I'll test FEC).

I don't need blind scan - just the ability to tune into things with only those three parameters (that's not exactly scanning...)

[SergioDanielG]

But symbol rate, frequency and polarisation are always specified by the software; rolloff I think it works without, not sure whether or not it works without FEC. Modulation is the only one I noticed it definitely requires (but I'll test FEC).

I don't need blind scan - just the ability to tune into things with only those three parameters (that's not exactly scanning...)

Ok, dvb cards without blindscan hardware can't know real parameters, only probing one for one all parameters, it's long time too...
All parameters are necesaries, but some are "default" parameters. For example, in Hispasat 30°W, TP 80, Uruguayan mux,freq. 11909, Pol. V, S.R. 7200, fec 3/5, rolloff 20, mod 8PSK. If you not put all parameters, you can't lock. This is a tp I can't lock using "mplayer dvb://" I need to zap with "szap-s2 -p -H -r -M 2 -S 1 -O 20 -C 35 -c myChannels.conf "Channel" and in other terminal "mplayer /dev/dvb/adapater0/dvr0"

Do you plan use other sofware like kaffeine for example?

Best regards.

[Muzer]

Oh, I see.


Thanks for the tip - I was wondering how you watched channels in mplayer via szap-s2, now I know




Yeah, I'll probably use MythTV after a while but I'll need to set aside time to set it up - I'm glad I now know how I can just use mplayer. I've gone off Kaffeine ever since it made the move to KDE4, though it might be better now, I should check... it just seemed to lose a load of the features that made it really good.