[mythtv] [PATCH] viavld interlaced patch
mythtv at ratty.org.uk
Sun Oct 3 15:15:36 UTC 2004
On Sun, 2004-10-03 at 06:55, Terry Barnaby wrote:
> Robert Clark wrote:
> > I've had another look at this and I am now seeing evidence of
> >interlacing (flickering when paused during motion). Bizarrely, this is
> >only happening some of the time, though, so I think it's not 100%
> >correct yet.
> > One thing which you've probably already checked is scaling. I had
> >great difficulty convincing MythTV not to scale the image and any
> >vertical scaling destroys the interlacing. Eventually I gave up and
> >patched it to hardcode the display aspect to match the source.
> One thing on this, what is your MythTv setup ?
I'm using Fedora Core 2 with kernel 2.6.8 with the epia2 drm kernel
patch (drm version 1.3.0), Xorg 6.7.0 with Unichrome driver r25 &
libviaXvMC 0.11.3 and MythTV CVS from 2004-09-24.
On top of these I've added patches to get the new drm to compile with
the FC2 kernel, disable the hardware flicker filter, the qmatrix and
jitter fixes for MythTV you posted on the Unichrome mailing list and a
patch to fix the aspect ratio.
I'm running X with a 720x576 50Hz modeline, TV output only, PAL
format, S-Video out & overscan. Via (VLD) hardware acceleration is
enabled in Myth, deinterlacing is not.
> I presume you are using a PAL/NTSC TV as an output device ?
> If you are using, as I am, a Via M10000 box that includes the VT1622
> TV output chip (or similar),
I have an MEII6000 with the VT1622A TV encoder.
> this has a "de-flicker" option which is enabled
> by default in the Unichrome Via X driver.
> For watching Video I have turned it off with a hard hack (patch enclosed).
Thanks, your patch is better than mine (it actually has comments) :)
This should probably be made an X driver option at some point, I
> What is your video source to get the interlaced pictures ?
I'm using two video sources for testing at the moment. One is a region
2 PAL DVD (Father Ted) which I can play back through Unichrome patched
MPlayer. This looks fine from the point of view of interlacing, so it's
a good reference for comparing Myth's output to. The other is a DVB
recording imported into Myth (I don't have my DVB card yet). I can also
play this nuv file back through MPlayer for a closer comparison of the
Have you tried MPlayer at all? To my untrained eye the output looks
perfect. The only problem is the lack of sync-to-vbl means the sync
drifts and, eventually, the fields get displayed in the wrong order.
Probably not that difficult to fix for someone who knew what they were
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