Genpix USB module/Dvbdream receiption bug?

[jerryt]

Setup; DVBdream 1.2c with genpix firmware 2.0

When scanning T5 (97) with the Genpix module, Dvbdream only finds 34 channels (TP26).

Duplicating the scans with the same copy of Dvbdream and either of my Twinhan or Skystar2 cards yields over 200 channels.

The Genpix module finds all the channels when used with TSReader.

In addition; with Genpix module on other satellites, play back will stop if signal strength drops below 50%.

IE. During scans of T5, Dvbdream shows signal strength as 45%, PMT does not fill, and then no channels are found.

Relocation your product is awesome, please keep up the great work.

Maybe you can come vacation here in NA when you are ready to take your next holiday!!

[rel]

Hi Jerry,

Genpix sent me an update for his DD device interface. I'll include it in v1.2d. but also attaching to this post. If DD was working ok before on the same TP with Genpix, this update could fix the prob but I'm not sure.

Relocation your product is awesome, please keep up the great work.

Maybe you can come vacation here in NA when you are ready to take your next holiday!!

Thanks,

It will be hard for me to find enough time/possibility either to take a holiday or to work on DD soon, but that sounds nice, ty, I hope I will be able to do that one day.

[genpix]

It's a known "bug".
When the signal strength is too low, there is a lot of garbage in the data-stream (stream is simply broken).

DN 8PSK module has Error output (besides DATA, Valid, and Sync).
CPU inside IRD uses this Error as Interrupt input.
It could cause the reset of data analysis or call for some additional communication between CPU and 8PSK module.

But in no way it could fix he stream. It just flags the error.
My adapter does not know what to do with this flag. It just ignores it.

Please report how many CEs do TSReader or DD report when you tune to this TP.
I bet, there are plenty of them. And signal is unusable.

By the way, when you have 50% signal strength in your receiver, you reception is constantly breaking as well.

I'd like some clarification though:
Are you sure that Twinhan or SS2 card could give you a good signal on these weak TPs? If they produce the same breaking stream, what miracle you expect from 8PSK module?

[genpix]

genpix Device Driver does very simple "analisys" of the stream integrity: it checks for the proper packet header.
If header is incorrect (does not confirm DVB-s specs), driver resets the stream.

TSReader does a better job, I guess. It does not reset the stream, it tries to find a new sync pattern.
In any case it skips several incomplete packets as well.

This difference in the stream integrity analisys could explain why TSReader is able to find more channels then DD.

But there is no miracle here. If TSR could find all the channels on a weak transponder, it does not mean it could FIX them. It would generate breaking signal as well.

I'll look through my code and try to improve signal analisys algorithm (instead of stream restarting, I'll try to drop pcketas with wrong header).
But don't expect much from it.

Bigger dish is a only way to fix it, imho.

PS: ask for advise in DVBN forum about dish size for Intelsat reception in your area.

[genpix]

try this new version of the driver (ver.1.2.1).

It resets data-stream thread after every tune command.
Let us know whether it helps.

Edited: driver has been deleted (it had a bug)

[jerryt]

Bigger dish improved signal strength to 65% on T5 but still does not scan correctly (Dvbdream1.2c and Genpix device 1.20)

Tried Dvbdream 1.2a, same scanning problem

Tried AMC3, "no channels found".

Genpix device 1.21 lost the two TP's I was getting on T5.

Installed Dvbdream 1.1h and original usb drivers with Genpix device 1.0.4 and ...

SUCCESS!! 184 channels on T5. Tried my other linear satellites and they are scanning normal again with 1.1h

I can upgrade this computer one step (version) at a time, until the problem returns. Could someone provide me with an upgrade path and links to the different versions? Dvbdream is simple, but the different Genpix devices have me confused.

[genpix]

OK, I found a bug in my DD driver code.
QPSK modulation with SR other then 20000 does not stream correct.
Let me modify the code to support other SRs...

[genpix]

here is an updated version of 1.2.1 Device Driver.
Should take care of other SRs.

Also, it should tune to couple of Turbo-8PSK transponders on Anik F2 (with several HD channels).
Not sure whether DD would be able to read channel info from them (they have DC II style - TSReader plays them though).

Could you please check how it works for you?

[jerryt]

WOW!!!! (Dvbdream1.2c and Genpix 1.2.1)

New Genpix device 1.2.1 gives me 245 channels on T5. This is up from only 34 channels with device 1.2.0

Genpix, you are great, Thanks for your help!!!!!

[rel]

fixed in v1.2d (device update included in this version)