[mythtv-users] Slightly OT? - Video Quality

[Steven Adeff]

On 2/21/07, Greg Kettmann <greg at kettmann.com> wrote:
> Does (or can) MythTV Hardware provide a "professional" quality image
> (same as expected from TiVo, etc.) and, if so, must you buy high end
> components? (Note, current tests were done under Windows and I've
> returned the output/display card since I was unimpressed).  I'm looking
> for a sanity check here, before I start again.
>
> Here are the, rather long, details.
>
> I've been reading this forum and asking questions for 6 months or so.  I
> decided to take some baby steps toward building a unit.  It's been a
> disaster, but all HW and not specific to MythTV.  It's a matter of
> finding (working) suitable hardware, _with_ an AGP slot.  Being a
> typical geek I've a few systems floating around but so far nothing I
> have will work.  I finally grabbed my main desktop machine and ran some
> tests using it.
>
> I bought a video card which supports HDTV out, specifically it has a
> dongle for Component (YPbPr) (an inexpensive implementation of the
> GeForce 6200-  Leadtech A6200TDH).  I've a 3-4 year old Sony rear
> projection big screen (53" - KP53HS10) that is capable of 1080i.  I have
> a high quality 6 foot YPbPr cable which connected to the dongle (the
> dongle is 6" and it would be tough to get to the TV with less than say
> 4').  I was using Windows at this point, just playing around with
> settings and presentation.  What I found was discouraging.
>
> The settings for 480i and 480p seemed to do the same thing on the TV.
> It seemed to be 640x480.  It suffered from what I think is called
> "overscan" where the "picture" was bigger than the screen and I couldn't
> scroll around.  There was about 10-15% of the outer edge which I
> couldn't view.  More importantly, played videos (MPG's and AVI's) were
> very dark when viewed with PowerDVD or MS Windows Media Player.  I could
> turn up the brighness (in PowerDVD and WMP) but then it tended to be a
> bit washed out.  Please note that I was using "downloaded" test video
> segments (bit torrent), but they play just fine, with good quality, on
> my laptop. Also, normal "Windows" brightness was just fine.  It was only
> the played video that was dark.
>
> The next "usable" (no TV support for 720i or p) was 1080i.  There was
> significant "jitter", kind of an interlacing thing with the image
> jumping up and down slightly (in Windows).  No overscan.  Windows screen
> text nearly unreadable (small and slightly blurry).  I was able to play
> videos, again through PowerDVD and Windows Media Player and again they
> were quite dark.  The downloaded (supposedly HDTV) video tracks were
> weak at best and certainly no better than what I saw with the regular
> 480x stuff.
>
> So, first observation is that my TV, although rated for 1080i, isn't
> really up to the task.  Not too big of a deal.  I just means I forgo
> HDTV for awhile.  The new TV's are much better and support DVI anyway.
>
> The video quality is an issue though.  Is the "darkness" (of played
> videos) caused by the video card?  Normal Windows stuff was fine.  It's
> only the played video whether in a session or full screen.  Might
> another card provide better results?  Does anyone have any practical
> suggestions for a card (as in, I have a card with YPbPr output, which
> I'm using, and it works well, the card is...)
>
> How about the "overscan"?  Are there settings in MythTV to fix that?  It
> appears I'll need to be using 480i or p but not until I can get around
> the overscan.  I know there have been topics on that so I'm confident
> that particular issue has been discussed on these boards.
>
> I just wanted a sanity check on getting started and so far it's not gone
> well.  I think I'll give up on HDTV for now and plan on just building a
> good HD Front End later.  For best quality I think I still want YPbPr
> output since I've never been impressed with SVideo or Composite. I'm
> just looking for a moderately priced way to start working with MythTV,
> but so far I can't even find suitable hardware that gives results
> equivalent to "regular" TV.
>
> The next step will be a capture card.  I'd figured on the PVR-150 but
> those aren't conveniently available at the moment and people seem to be
> getting the replacement card, which has no Linux Drivers available.
> There is plenty of discussion on capture cards here.

I think you'll find that once you get MythTV installed your best bet
is to run only at 1080i and to upscale everything in Myth to that
resolution. As well, with a proper 1080i modeline you should not see
any flickering in the menu or during playback. If your TV has DVI/HDMI
input I'd recommend using that.

As to the PVR-150 issue, get a PVR-500, I realize it costs more, but
it at least gets you two tuners.

-- 
Steve
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