Blind Scanner Request

[st1905]

I love to watch feeds but as you know it is hard to find their frequencies so i want ask you can you make a blind scan function in dvbdream?.It would be great.

Thanks in advance.

[Betatester]

I'm afraid that not all devices can handle blind scanner function - for sure SkyStar rev. 2.3, but I don't know how about others (for sure SkyStar 2.6x not)

[Rockin' Rick]

We've discussed this a few times. Now with direct hardware support it may be feasable. It's always been possible but performance would be very poor and very very slow.

That SkyStar card is a little different.

Some cards may or may not play nice. The card needs to be able to report back to software detection of a carrier without being locked to a stream.

[Nrmf]

how do i get one of those dishes

[BxS]

Some cards may or may not play nice. The card needs to be able to report back to software detection of a carrier without being locked to a stream.

You can do that with some cards, but you only get the frequency, not the symbol rate, the symbol rate is the problem when is a low value.

[Rockin' Rick]

What we need is for the card to report it has detected a signal and at what level.
The software scans a range of frequencies looking for carriers. When the card reports it has found a signal above a particular threshold you continue scanning until it falls off again. Then you tune to the center. Use some math to estimate the signal's bandwidth. Assuming the modulation method you begin scanning through symbol rates over a range that the bandwidth suggests.
That's pretty much what the blind scan IRDs do. You can see that software would be able to do this with any dvb card that reported a received signal strength without being locked to a stream, if there are any. The cards only do what you tell them to. This may prove to be too slow to be practical. With DVBCore it would certainly be far too slow. The blind scan IRD's tuners were built with this functionality in mind.
I imagine with cards that play nice the speed would be about the same as an IRD.

If this can be made to work the possibilities are many. Compared to the abilities of these IRDs, in software there can be many functions. Automatically adding channels to the channel list, adding to TP lists, sorting, detailed scan rules such as scan from a to b and from c to d, skipping over known signals to save time, scan only one polarity, scan only for high or low rates. The copy to clipboard stuff in DD would be great too, you'd have everything you might want to know about the new channel.

It would be the coolest thing ever. But until somebody (Rel) digs in it's hard to be sure it would even work.