Seemingly random ATSC smudging pixelation on HD channels

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sdowney717

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Seemingly random ATSC smudging pixelation on HD channels

#1

Post by sdowney717 » Wed Mar 26, 2014 1:24 pm

I have 2 HTPC. One very powerful, everything works ok using a vbox 3560 usb tuner.

I built another lesser PC. It sometimes has problems with the picture and sound breaking up. Pixelates, smears, pieces of picture move and some stay in place and once that starts, it does not stop even when changing channels.
Both HTPC work off same signal antenna.
Othertimes like right now, it is perfect. So far this AM playing for over an hour with no trouble. This problem is mostly for HD channels. SD sub channels seem to play ok. Left it on all night on SD channel and it was fine.

Hardware is
Pentium 4 , 478 CPU 3.2 ghz Prescott clocked up to 3.66 ghz and system stable. (set to mormal did not help)
ATI Wonder HDTV PCI card
HD 2600 PRO video AGPcard
OS Windows 7
MSI motherboard ms 7104 v2 PCI slots are version 2.2

Yesterday, when it kept screwing up the picture, I pulled the wonder card and put it in a 3.6 ghz core2duo and it streamed HDTV absolutely flawlessly perfect, no glitches. Ran off the same coax line.

It is like the 478 cpu msi 7104 main board throws a fit and the signal will go crazy. Only fix and it is temporary, is to close WMC and repopen. Then it plays good for any where from a minute to an hour, eventually breaking up again.

I dont think it is hard drive related because while WMC was playing perfectly, I ran a malware bytes scan and WMC kept playing perfectly.

Another weird clue is I downloaded EasyHDTV DVR, running it produces a flawless perfect smooth picture, It never breaks up with Easy HDTV DVR, records fine as it streams ATSC.

I am wondering if it is signal relalated? I was reading ATSC uses error correction. Perhaps with WMC, the signal starts having an error, WMC being more complex software, the CPU can not keep up and it just all falls apart. Restarting WMC does some kind of reset and it works again for a random while till ATSC errors overwhelm the software.

So where does ATSC error correction occur in the device or in WMC?

So I plan to replace the antenna with a bigger one. Idea being less multipath, better quality signal. New antenna UHF section will be twice as large.

So what do you think? I kept clocking the board higher thinking it is cpu related. And it seemd to make the problem less.

sdowney717

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#2

Post by sdowney717 » Wed Mar 26, 2014 2:31 pm

Reading this some channels might use it.
Perhaps also some software might be better at fixing errors in ATSC.
After working for over 2 hours, right now the signal is falling apart.
Error correction[edit]
Error correction is a technology that is used by the ATSC tuner to make sure that any data that is missing can be corrected. For instance, sometimes interference or a poor-quality signal will cause the loss of some data that the ATSC tuner receives. With error correction, the tuner has the ability to perform a number of checks and repair data so that a signal can be viewed on a TV set. Error correction works by adding to the signal before transmission some extra information that can be used upon reception to fill in gaps. Therefore, error correction has the opposite effect of compression—it increases the amount of data to transmit, rather than reducing it like compression does, and it improves the quality and robustness of the signal rather than reducing it. Compression removes redundant (and some non-redundant) data, while error correction adds some redundant data. The reason for using error correction rather than just using less compression and keeping the redundancy that was already there is that error correction systems are specially designed to get the maximum benefit out of a very small amount of redundant data, whereas the natural redundancy of the data doesn't do this job as efficiently, so with error correction the net amount of data needed is still smaller.
There is a subsection in the ATSC standard (ATSC-E) that allows broadcasters to add extra (and variable types) of error correction to their broadcast streams.
This error correction service is not mandatory in the US, nor is it mandatory in Canada.
It is not known how many HDTV receivers support this error correction standard.
For the transmission of HDTV at 720 or 1080, an extra 1% to 3% added error correction codes will help reduce some of ATSC's poorer performance with weak signals under adverse multipath conditions.
Reception is greatly reduced due to EMI in the shortwave to VHF and UHF bandwidth from nearby computers of all sorts [light], portable WiFi and Broadband internet [medium to strong], microwave ovens [burst while activated], cell phones and the towers they communicate with, and even power lines with electronic transmissions.

dmagerl

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#3

Post by dmagerl » Wed Mar 26, 2014 4:22 pm

If SD subchannels are OK, but HD main channels arent, then its not an ATSC problem.

First, the AGP bus is at best marginal when it comes to playing HD channels.

Second, the 2600 was marginal when playing HD channels. Also, the 2600 doesnt do full MPEG2 hardware acceleration (increasing the amount of data sent on the AGP bus). You'd be much better off with a newer video card, but you're probably stuck with the AGP video bus so that probably rules a new card out.

Overall, I'd say the video capabilities of the mobo and video card are underpowered.

sdowney717

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#4

Post by sdowney717 » Wed Mar 26, 2014 4:57 pm

Well I have seen the same glitch on SD channels, But not to the unwatchable extremeness on the HD channels.

My zipcode is 23608.
Oddly channels 3, 4, 10, 13 are the worst. Channel 15 33, 43, 45, 49 are much better regarding this glitch.
channel 3 is by far the most susceptible to this glitch.
Perhaps because SD has much less data than HD it is less noticeable?
It may be the hardware is not powerful enough for WMC to run properly.
Although why it works fine with EasyHDTV PVR on HD channels?
Seriously picture perfect using that program. It started glitching with WMC, so shut it down and immediately loaded EasyHDTV and since 10:30 been fine.


I swapped out the HD2600pro for an even older x1300 pro and it is playing fine with EasyHDTV. So I am not convinced the video card is a problem.

I wonder if an agp setting in the bios is an issue?

I wont make any decision to use the core2duo board till I get the better antenna up.

sdowney717

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#5

Post by sdowney717 » Wed Mar 26, 2014 5:15 pm

I enabled agp fast write in the bios
http://www.techarp.com/showFreeBOG.aspx?lang=0&bogno=39
So far it is playing fine in WMC on the worst channel 3.
Will post back if anything improves long term. Hours of play it may take to expose the glitch. Once it glitches it will not stop unless you shut down WMC.
Although rarely switching channels stops it (less than 10% of the time), Once it starts glitching going crazy, the glitch will then show up on all channels, even SD channels.

sdowney717

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#6

Post by sdowney717 » Wed Mar 26, 2014 8:21 pm

hmmm, so far it has not had a problem. :)
still not enough time to be sure.
agp fast write writes directly from cpu to video memory, bypassing system memory.

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#7

Post by sdowney717 » Thu Mar 27, 2014 12:35 am

Still working perfectly.
Must have been AGP fast write needing to be set.
This is great, now I can move on. This has been a pain for over a week trying to figure it out.

I am still using the x1300 pro. It also plays Netflix in WMC fine.

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#8

Post by sdowney717 » Thu Mar 27, 2014 10:03 pm

Still working fine.
Must have been the AGP bios settings.

I can force it to glitch by logging into the PC using Google Chrome remote desktop and play WMC ATSC in a small window at the same time.
That puts a lot of stress on the video system and it will break up.

My guess is the Wonder card was sending data just fine the whole time. The AGP system could not handle the amount of data being written from CPU to memory then AGP having to get it into the video card, that was too slow.

Before I found out about AGP fast write, I did test this wonder card and WMC on an Intel 875 chipset MB 478 system and it also glitched, so I knew the MB was ok since they both acted the same.

sdowney717

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#9

Post by sdowney717 » Fri Mar 28, 2014 3:02 pm

Yikes, I played around installing some things and picked up 3 PUP malwares!
ATT tool, ATI tools, something else.

Anyway cause the glitch to come back badly.

So ran Malware bytes, it removed them reboot and everything is good again.:D

I think on slower older hardware, the PUP programs will show up quicker since the hardware is not powerful enough to keep you from noticing.

I also have not put an AV program like Avast on here yet.
But have never seen Avast prevent PUP installs.

sdowney717

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#10

Post by sdowney717 » Fri Apr 04, 2014 9:07 pm

Updating the thread, all the pixelation and smearing came back, even with AGP fast writes on.

So I pulled out the x1300 pro video card, and put in the HD 2600 PRO video card and it is fine once again. So I think my old x1300 pro is dying, worn out.

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#11

Post by sdowney717 » Mon Apr 07, 2014 12:09 am

THE FINAL UPDATE.
I found the smoking gun..

Not the video card, the HD 2600 PRO starting showing the problem again.

The problem was my add on pci Intel PRO/1000GT NIC card.
On this board, the bios assigns IRQ16 to the AGP slot.
I had the NIC in PCI slot 1, on this board that slot shares the IRQ with the AGP slot.
So the NIC card and the Video card were sharing irq 16.

Solution was simple, move NIC to pci slot #3, now it has irq 18
agp is irq16
pci1 is irq16
pci2 is irq 17
pci3 is irq 18

I also disable 0 ws for the PCI bus, which helps stabilize the PCI bus if the board is overclocked.
Anyway, after all that, so far no trouble with the video streaming.

I remember now that all this started when I added that gigabit NIC card. It was so irritatingly random issue, drove me crazy and nothing made any sense until today.
started a thread there showing the irq assignment problem.
http://www.sevenforums.com/performance- ... ouble.html


both on irq 16
Image

now video by itself on irq 6 and nic on irq 18, winhdtv on irq 17
Image


AND I find someone else having a problem just like mine with AGP and PCI slot i with a NIC
http://forums.anandtech.com/archive/ind ... 99248.html
http://www.dslreports.com/forum/r219177 ... -with-PCI-
My experience is IRQ sharing does cause problems regardless of what is supposed to not happen.

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#12

Post by sdowney717 » Wed Apr 09, 2014 10:34 am

HaHa on me, It is finally truly fixed, but it was not the slot. Even though that made some sense to me.
It all came back that glitch.

So I put in another hard drive, reinstalled windowsm updated all important security updates and optional platform update.
Everything working perfect, even with IE11

THEN I installed Chrome browser, and the glitch came back.
Then I uninstalled Chrome and the glitch went away.

So all along it was chrome. Chrome runs a lot of background processes. Which in settings you can turn off when exiting chrome.
Within a few minutes of installing chrome, the awful smeary glitch showed up. The very random nature of this must be chrome deciding according to its own internal design.
I thought maybe it was extensions, because I would always install chrome on all my pc, then login and many extensions will install.
So I uninstalled chrome, then re-installed chrome, but did not sign in and still it starts glitching. So for now no chrome on this PC.

So I cloned my good working drive for a backup using clonezilla.

Some info on this spyware type activity with chrome,
http://www.howtogeek.com/180175/warning ... ng-on-you/

shutting down chrome background action
https://support.google.com/chrome/answer/1184722?hl=en

IMO, chrome must be exploring your drive and phoning home and all the extensions too. All this extra activity interfered with my slower system so HDTV streaming was poor.
The drive was always very active when chrome was running.

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#13

Post by barnabas1969 » Wed Apr 09, 2014 1:03 pm

Chrome is installed on my HTPC and there is no issue. I use exactly three extensions: Ad Block, Auto Remote, and Google Docs.

sdowney717

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#14

Post by sdowney717 » Wed Apr 09, 2014 11:49 pm

barnabas1969 wrote:Chrome is installed on my HTPC and there is no issue. I use exactly three extensions: Ad Block, Auto Remote, and Google Docs.
yes, would not be a problem for me except that this PC is socket 478 pentium 4 ddr 2gb 3.2ghz cpu.
The system is weak, low power. I have it overclocked to 220 fsb and 3.5 ghz cpu.
I am also running windows 7.
It has been perfect since I uninstalled chrome
I kept updating the thread in case others run into a similar problem.

I have another HTPC with a quad core AMD phenom 9650 cpu and it can do it all.

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#15

Post by sdowney717 » Thu Apr 10, 2014 2:50 pm

yup still fine, still working, no chrome installed.
Within a few minutes after chrome is installed, smearing pixelation awful looking streaming and sound breaks up.

I dont have chrome installed. I was watching tv, an windows 7 started using the hard drive doing, light flashing fast, etc... whatever it does, and still perfect streaming full screen HDTV ATSC OTA from my antenna.
So something is in chrome even with no added extensions that does something heavy duty usage to the system, which if your PC is standard for today you will never know what it is doing to you in the background.
I also unplugged the PC from the LAN, but chrome was still causing the affect.

I do think I could run chrome if I in settings told it to stop running background processes on exit. But with IE11 seems ok, so little reason right now to reinstall chrome just to find that out. I did like configuring this PC using Google chrome remote desktop app, so I loose that functionality.

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#16

Post by sdowney717 » Thu Apr 24, 2014 12:03 am

Still working fine.
Have never re-installed Chrome/
Perfect picture, smooth.

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#17

Post by sdowney717 » Mon Feb 09, 2015 3:14 pm

Still working.
I also cloned a bigger 320gb MAXTOR IDE drive and I am running that now.
I just wanted to say it is still working
I never did reinstall Chrome.

I wonder if I used a sata drive IF since it is faster than IDE, would Chrome browser not interfere?

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#18

Post by sdowney717 » Wed Aug 26, 2015 12:41 am

Well, it is not working.
It has been a while but I gave up in disgust sometime ago as the glitch came back, so today I hooked it up to run it and this
is what it does, after about 5 hours. Only way to fix it is close and reopen WMC.
I recorded a video, it does this on all channels.
https://www.youtube.com/watch?v=s-LyaembNUI

I still wonder if a sata drive would fix it.

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#19

Post by STC » Wed Aug 26, 2015 2:44 am

Could that be a GPU problem?
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#20

Post by sdowney717 » Wed Aug 26, 2015 9:59 am

I tried another GPU and it eventually did the same thing.
I thought it might have been which is why I bought a different one.

First GPU was an ATI x1300, second is this HD2600

Also the PC plays netflix fine.

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