judder

[sardukar]

hi all,

i am running an Amiko Alien 2+ (triplex)

i am using the OpenPKT Hyperion 2 image.
its working great, but i have noticed an odd issue.
when watching HD channels the picture and sound judder from time to time.
i have to switch channels and switch back again.
i have not seen any pattern to it, and it happens on all HD channels.

any one else see this?

[Satphoenix]

Re: judder

This is a known problem on some hd-receivers. The reason is a software problem in the handling of variable bitrates in combination with the time-stamps/sync-marks. In germany we had this problem very extremly on some receivers since some providers changed to it one year ago. This was so extremly that these channels were unwatchable.
So nearly all receivers here got a software update after a few weeks which solves the problem.
Other reveivers with older tuner-software (part of the os) still have sometimes this problem which can be solved by switching to another hd-channel and switching back. But after a short time the receiver stumbles again over a sync-mark while extreme bitrate-change, sets it to a wrong position and picture and sound are not synchron or the picture gets juddering.

[mahrkpat]

Re: judder

I saw this quick fix on another forum I don't know if it works or not because I my self don't have this issue:

goto menu
setup
system
a/v settings
change video output to hdmi-pc
change resolution to 1600x1200 (this is were we need other people to test the res) ie 720p tvs
aspect ration to 16:9
display content to just scale (on both)

click ok


now the screen may be just half you tv just turn over and back again

it should then fill the full screen

also if you install the autores plugin switch that off

[russellhearn69]

Re: judder

too keep you video quality on 1080p all you have to do is change from 50hz to 25hz, thats what i done ad the juddering stopped, this is just a temp fix until the developers resolve the issue

[mahrkpat]

Re: judder

Judder problem fixed with new openpli image. (I think for triplex only at the moment)

OpenPLI for for sti7162 boxes __http://sourceforge.net/projects/openplihybridfo/?source=dlp

[Satphoenix]

Re: judder

...change from 50hz to 25hz, thats what i done ad the juddering stopped...

If that is the reason for juddering, you probably have a hdmi/tv problem.
What you did this way is to reduce the data-rate through the cable.

[mahrkpat]

Re: judder

If that is the reason for juddering, you probably have a hdmi problem.
What you did this way is to reduce the data-rate through the cable.

My friend the 25hz fix is a known fix for the juddering HD it has been tested by
people with a tv's with that option.

[Satphoenix]

Re: judder

But the reason for that is completly different to the reason I described in post 2.
The problem of sardukar seems to be (for me) the decoding/sync problem.
When the new openpli image has new tuner-software, his problem will be solved.
Wit the "25hz fix" you reduce the data-amount via hdmi to the tv. In this case it's not the receiver with his mpg-software, it's the tv. If it helps in this cases, ok!

[mahrkpat]

Re: judder

You are very well informed thank you for making it more clear it would be nice that if the
other images will eventually incorporate this fix although some are saying it will be fixed
when services move to new sat in November.

[sardukar]

Re: judder

@satphoenix.
yeah thats the issue alright, when i reduce to 25Hz, the judder stops but then the picture become way too "laggy" and watching it for a prolonged period just hurts my eyes, its like there is ghosting on the screen.

hopefully the PKT guys will get this rolled into an update soon.


all, i ran the system at 720P for the weekend, i didnt notice any judder, but i was only able to watch an hour or so of TV, so not too sure if its there or not. the system is still at 720p, so will keep watching and let you know if i get any judder

[sardukar]

Re: judder

update.

not much to report yet, still not had much time to watch TV.

no PKTeam update yet for the judder fix.
will get OpenPLi and give it a go this weekend.

tried HDMU 11813 last weekend, not good!
could not install any packages from online. it wanted me to opkg update/upgrade.
so i backed it up and put back on my build of OpenPKT.

[mahrkpat]

Re: judder

Hi sardukar I thought you had a triplex if that is the case you can use image I had given a
link to, I would think it would take the PKT some time before they can implement a fix on
their image even if it is based on OpenpPLI.

could not install any packages from online. it wanted me to opkg update/upgrade.

This is fairly simple procedure all you do is download plugin file you want it will be in *.ipk
format, you just ftp it to you tmp folder then use telnet and type opkg install /tmp/*.ipk.
You can also use 7zip to unrar the .ipk file until you see the folder structure eg usr then
ftp it to your box.

ps sometimes when I have updated a plugin from plugin panel it has broken something
else eg Tsmedia breaking webif.

[championc]

Re: judder

I would think it would take the PKT some time before they can implement a fix on
their image even if it is based on OpenpPLI.

Hi there

Why do you think this ? Are both OpenPLi and Hyperion v2 not both Python 2.7 OE2.0 Based Images ?

[mahrkpat]

Re: judder

It is actually getting the coders getting interested enough or putting in the time to add the
fix because at the same time they are usually working on other projects take HDMU team as
an example lots of new releases but the image doesn't really seem to improve only cosmetic.

[championc]

Re: judder

HDMU is built around Python 2.6 OE1.6 so it would seem there are definite differences to be negotiated but I would have thought the for PKT it's just a merge and re-compile (or whatever they do).

It could be said that there's very little more that can be done with HDMU and maybe only cosmetics are the only things which remain within the boundaries of what can be done with Python 2.6 and other 2.6 based images.

I know the VU+ is 2.7 based and realistically, development will always follow the box with the best potential and longevity