37 replies to this topic

[gabier]

Hello everybody,

This is my first post here, as I installed OpenPLi 4.0 a few days ago on my DM8000 with 2 DVB-C tuners .

Before, I had an old Gemini image with CCCam softcam, and I got into troubles with pixellisations (blockiness in english?) and sound disappearing at times, mainly at peak hours.

The first thought is to investigate the quality of the signal on the cable. But I have a decoder box of the cable provider and when used instead of the Dreambox, there are no perturbations at all. I changed several times to be sure but there was never any perturbation  with the provider's box and at the same time "clear" perturbations with the Dreambox.

I was advised to install a swap file and indeed it seemed to solve the problem. I thought that my DM has a rather little RAM (256Mo) and that the swap could indeed help the image to have enough space for the signal treatment.

I was also advised to move to a more modern image, because maybe such an image could implement a better signal quality. This is why I decided to install OpenPLi.

The perturbations seemed to disappear, and then came back. This is why I implemented a swap file in OpenPLi.

Gemini had a built-in swap creation option. OpenPLI does not seem to have one. I used the plugin Glass System Utilities to format an USB key and create a swap file.

But this swap does not seem to be working properly, because GSU monitors it and reports a use rate of 0. At the same time I see pixellisations ans sound disappearances.

Now I am quite confused:

Have I everything wrong and my problem is not a memory problem ?

Does OpenPLi manage swap files less efficiently than Gemini ? Is there any swap mangement at all ?

Is GSU usage report wrong ?

 

It would help me if somebody can explain me how swap is managed in OpenPLi, if the softcam uses it also, and if there are means to monitor the swap file usage rate directly rather than by GSU.

Also if somebody can advise on how to debug this pixellisation problems, it would be great.

 

gabier

 

[Robinson]

I'm not an expert but why would you need swap to receive a cable signal?

Do you have a subscription card? What scrambling system is it? Are you using CCcam or Oscam?

[Pr2]

Hi,
 
You need to install the swap management utilities and use them to properly create a swap, this is not installed by default in OpenPLi.
 

opkg update && opkg install util-linux-swaponoff

 
Then google for:  mkswap, swapon, swapoff commands for details.
 
Pr2

[Dimitrij]

use

[gabier]

I'm not an expert but why would you need swap to receive a cable signal?

Do you have a subscription card? What scrambling system is it? Are you using CCcam or Oscam?

Yes, I have a card, Mediaguard, I suppose (provider Numericable in France). I have installed Oscam, CCCam and Hypercam in order to test them. Currently I have Oscam running.

The idea of the swap came up because if the signal is OK and the DM is OK, maybe the DM has less memory than the provider's decoder and this lack of ressources is responsible for the bad output.

[goldeneye]

_{Your dreambox has amply RAM and probably much more than the supplied cable box.. Blocking occurs due to ill-timed ECM requests (either supplied too late or not at all. This stops the decoder briefly reulting in artifacts. This is a known problem with the use of stricter encryption rules..}

[Dimitrij]

Check the free service.

[gabier]

_{Your dreambox has amply RAM and probably much more than the supplied cable box.. Blocking occurs due to ill-timed ECM requests (either supplied too late or not at all. This stops the decoder briefly reulting in artifacts. This is a known problem with the use of stricter encryption rules..}

Thank you goldeneye, i am glad to have an idea of the origin of the problem. But is there something to be done ?

BTW, do you think 256Mo is "amply RAM" ?

 

gabier

[goldeneye]

Most providers try to lock every Open box from using their services. They do this by:

 

Pairing the card to the supplied STB (preventing it from being using in any other device UNLESS you know the Boxkey and RSA key)

Using special 'nano' commands that are only exist in supplied box. Meaning no CI or Softcam will work

Very frequent change in AES or other decryption keys meaning that code needs to be refreshed within x milliseconds. This to prevent WAN or even LAN cardsharing.

 

256 Mo is more than enough for use in a STB. Example: My DM8000 has 4 legal subscription cards! One for Canal Digitaal, One for TV Vlaanderen, One for Digitenne (DVB-T) and finally one for Ziggo (DVB-C). The box runs at only 450Mhz and everything works like a charm. No hickups, artifact even when using 2 exactly the same CI's with differently locked CAID's..

[gabier]

Thank you for explainations. Probably my provider cannot completely lock to its boxes because he officialy supports a hardware cam in some tv sets.
But what can I do now? Throw away my DM?
gabier

[gabier]

Check the free service.

I looked this evening at a free station. I had plenty of trouble (blocking, sound stops, ...). No difference if I stop the softcam and remove the card, or if I restart it and reinsert the card. No difference between oscam, cccam or hypercam.

Doesn't this mean that it is not en encryption problem ?

Also, it occurs only at peak hours (between 19h30 and 21h). Should not encryption problems occur at any time ?

[Robinson]

And if you use your cable provider's box between 19:30 and 21:00 there are no problems at all?

[gabier]

And if you use your cable provider's box between 19:30 and 21:00 there are no problems at all?

No, No problems with cable provider's box. I tested this several times, changing from Dreambox to other box and back, But this was with my old Gemini image. I will confirm this point with OpenPLi this evening, if the problems occur. This is another point, the problems can disappear for several days, even weeks, that is why I thought with Gemini that the swap file had solved the problem. But this was maybe a coincidence. It does not seem to work with OpenPLi.

[gabier]

In order to be complete, I should report also that maybe my OpenPLi image is not absolutely clean although these problems should not be related to the TV displays. First, I had to flash the OpenPLi image using an old browser (FirefoxPortable) because my old Gemini image had an old bootloader not usable with modern browsers. I suppose that the openPLi image which is now installed has kept the old bootloader, and I will have the same problem when upgrading.

Second, some Linux commands do not work. When I could not use the "fdisk" command, I thought maybe the Linux in STBs are a little stripped off with not mandatory commands.

But the system now cannot find the command "ipkg" and I had to install a plugin using OpenPLi menus. Then I think something is wrong either with me or with the system. Do I Telnet incorrectly ? Is there a path to insert somewhere ? Or is the system corrupt ?

 

 

 

[goldeneye]

If blocking occurs on a FTA channel, the softcam nor the decoding routines are at fault. It simply means that probably the signal reception itself is at fault. Since you state that no problems occur with your provider's STB it is most likely that the tuner in your Dreambox is causing problems. At least if you are using the same cables to connect to your wall socket. If your DM is a 'clone' DM800HD-PVR it is a very common problem. Mostly caused by a weakened capacitor on the tuner board or even more evident - a worn power supply. I would recommend you to check these first..

 

Since DM800's are now considered ancient you might want to change this box instead of repairing it..

[Dimitrij]

ipkg --> opkg

fdisk --> sfdisk

Edited by Dimitrij, 28 May 2015 - 09:51.

[gabier]

If blocking occurs on a FTA channel, the softcam nor the decoding routines are at fault. It simply means that probably the signal reception itself is at fault. Since you state that no problems occur with your provider's STB it is most likely that the tuner in your Dreambox is causing problems. At least if you are using the same cables to connect to your wall socket. If your DM is a 'clone' DM800HD-PVR it is a very common problem. Mostly caused by a weakened capacitor on the tuner board or even more evident - a worn power supply. I would recommend you to check these first..

Since DM800's are now considered ancient you might want to change this box instead of repairing it..

The STB is a DM8000 and NOT a clone. Of course I suspected my tuners in the first place. I disconnected both in turn and there was no difference so I think that the tuners themselves are OK (both broken at the same time is unlikely).

Each tuner has an input socket and a "repeat" socket. The main cable goes to the input of first tuner and another cable goes from first repeater to second tuner input.

Are your capacitor and  power supply problems specifics of the DM800 or can they also happen in DM8000 ?

Also how can I check these ?

[gabier]

ipkg --> opkg

fdisk --> sfdisk

Thanks inded Dimitrij, it is quite a new thing for me !!!

Is there a logic ? "o" for "OpenPLi" ? "s" for ... ? Is there a list of sh OpenPLi commands ?

[MiLo]

The difference is just a matter of 'progress'.

The 'ipkg' program has been abandoned years ago, so modern distributions all use its replacement 'opkg'. What you are seeing is the difference between ancient code and a modern distribution.

If you must know, the 's' is for 'scriptable' but google would have told you that.

For a list of available commands (hundreds...) run 'busybox' to get a general idea. Or just list the directories /bin, /usr/bin, /usr/sbin and /sbin. All these are standard Linux commands, so you can ask google what they do.

Normal users never need to bother with telnet commands, which, combined with the fact that there is nothing unique about them, also explains why there is no "list" for users.

[gabier]

If blocking occurs on a FTA channel, the softcam nor the decoding routines are at fault. It simply means that probably the signal reception itself is at fault. Since you state that no problems occur with your provider's STB it is most likely that the tuner in your Dreambox is causing problems. At least if you are using the same cables to connect to your wall socket. If your DM is a 'clone' DM800HD-PVR it is a very common problem. Mostly caused by a weakened capacitor on the tuner board or even more evident - a worn power supply. I would recommend you to check these first..

 

I opened the box and laid off the tuners. I could not see any ill-looking component. Probably in order to investigate further on the hardware side, I would have to send the STB to a specialised shop,  with no certainty that they find anything.

gabier