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pvr-250 mpeg artifacts after upgrade to R5A26
http://forums.linhes.org/viewtopic.php?f=17&t=7089
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Author:  awveale [ Sat Nov 26, 2005 3:41 pm ]
Post subject:  pvr-250 mpeg artifacts after upgrade to R5A26

I've just upgraded from KnoppMyth R4V4 to R5A26. I'm liking much
of the new MythTV version and the new KnoppMyth too, though I'm
still getting used to the new arrangement of the frontend.

But I'm having a serious problem with MPEG artifacts since the
upgrade, both in LiveTV and in recordings. These artifacts were
not noticible before the upgrade, so I'm pretty sure I'm looking at
drivers or settings, but I need guidance on what to check.

My capture card is a PVR-250 and I did the KnoppMyth Backup
before shutting down R4V4. Then I used the AutoUpgrade from
R5A26.

I have so far not installed any new software beyond R5A26, nor
have I changed any of the capture options.

I did have to edit the /etc/mythtv/modules/ivtv since it was
complaining about the "add below" and "add above". I changed it
based on a posting here, changing those lines to "install ..." and
"remove ..." I've rebooted and tested LiveTV and still have my
artifacts. Haven't had a recording since then yet, but I don't expect
it will be better.

I am still searching here and in mythtv's mailing list archives but if
anyone can help me short circuit the hunt, I'd appreciate it. Several
hours of search permutations is grinding me down.

If you need any specific information about my setup, please ask.

Anthony

Author:  ceenvee703 [ Sat Nov 26, 2005 4:47 pm ]
Post subject: 

Quote:
If you need any specific information about my setup, please ask.


Could you describe the artifacts rather than just referring to them as artifacts? Are you sure they're specifically MPEG2 encoding artifacts, or something else?

Do new recordings look like they're periodically hopping forward and back in time? (If you still have any old recordings from before your upgrade, see if they're playing back OK.)

Those were my symptoms when I upgraded my backend to R5 alpha. I solved it by upgrading my firmware.

http://mysettopbox.tv/phpBB2/viewtopic.php?t=3606
http://mysettopbox.tv/phpBB2/viewtopic. ... 0+firmware

EDIT: I only saw my problem with recordings, not with Live TV, so not sure it's the problem you're seeing.

Author:  awveale [ Sat Nov 26, 2005 5:06 pm ]
Post subject: 

Quote:
Could you describe the artifacts rather than just referring to them as artifacts? Are you sure they're specifically MPEG2 encoding artifacts, or something else?


What I get fall into 2 classes:

1) large square blocks usually limited to a small area or from
one spot clear to the right edge of the image.
2) large 2-D areas of smaller blocks

Class 1 is most frequent.

Quote:
Do new recordings look like they're periodically hopping forward and back in time? (If you still have any old recordings from before your upgrade, see if they're playing back OK.)


Old recordings play fine. New recordings play fine except for a skip
when class 2 is wide-spread.

I'll look through your links.

Anthony

Author:  awveale [ Sat Nov 26, 2005 6:38 pm ]
Post subject: 

[quote="ceenvee703"]Do new recordings look like they're periodically hopping forward and back in time? (If you still have any old recordings from before your upgrade, see if they're playing back OK.)
EDIT: I only saw my problem with recordings, not with Live TV, so not sure it's the problem you're seeing.[/quote]

Hey, well, that's familiar now.

I tried changing the firmware (twice now) and both of the newer
firmwares do this for LiveTV. A fractional second back and forth
hop.

The blocky artifacts I described before are strongly suppressed
though I do see them still.

[SOLUTION]
Hey, idiot (I'm talking to me now.), read the instructions.

The firmware update works better when you actually power the
system down before loading the new firmware. The IVTV wiki page
recommended 30 seconds or more and that seems to have done
it.

For LiveTV I no longer get the blocky artifacts that started me on
this thread, nor do I get the fractional second back and forths.

I've gone through several minutes worth of a recording with no
sign of either (all three) type of artifacts/events.

Thank you to ceenvee703 for pointing toward the firmware updates.

Anthony

Author:  ceenvee703 [ Sat Nov 26, 2005 8:36 pm ]
Post subject: 

You're welcome--glad it sorted things out.

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