Home > computer, displays, hackintosh, media, television > Hackintosh HTPC part 4

Hackintosh HTPC part 4

In Part 3 I briefly touched on screen settings, and ended up using the analog output of the HTPC at 1920×1080, 59.9Hz. Picture quality was good, and to my surprise the pixels output by the video card were perfectly mapped to the ones on the TV. I used the free monitor setup displays at http://tft.vanity.dk/ for testing, and applied setting for colour and sharpness that had been previously been set using a Home Theatre setup DVD.

The setting that made the biggest improvement here was sharpness. On my TV, a Samsung 46A656, the default setting was 50 on all inputs. I had assumed this meant no sharpening but a quick run through the test cards on the setup DVD showed this to be anything but neutral. A black pattern of lines on a grey background showed very bad white edges around the lines, indicating too much sharpening. Dropping the sharpening to 10 gave a much better image, and the colour setting was dropped to 42 from 50 using other tests.

With these setting applied to the picture looked great, but what about the HDMI input? Using a DVI to HDMI cable gave a cropped picture that showed lots of movement jaggies and looked way over sharpened. The last issue was again fixed by dropping the sharpness setting, this time to zero since a Digital signal shouldn’t need sharpening. A web search revealed that I needed to use a 1 to 1 pixel mapped setting on the TV, and a read of the manual showed this is called Just Scan on the Samsung TV. It’s accessed from Menu>Picture>Picture Options>Size>Just Scan, the default is Auto Wide which gives the cropped image.

The last problem was due to the video output being an interlaced signal, meaning alternate lines are displayed every scan cycle on the TV. Any movement in the picture shows the last frame mixed on alternate lines with the current one which appears as jagged edges. Another search found this page at Adam Nash’s blog. It appears there is a bug in Leopard that will only show 1920×1080 interlaced in the display setting of System Preferences. As Adam explains, enabling ‘Show Displays in the menu bar’ allows you to select a screen mode that isn’t interlaced. I initially had two 1920×1080 interlaced modes and one non-interlaced, this has now changed since the last three modes are shown by default.

display-menu-bar

This also allows easy changing to 1360×768 for a bit of web browsing since 1920×1080 is not clear enough from several feet away.

The HTPC has now been running for a month using these setting without any major problems. There is a small amount of what I can only describe as judder when watching video files, either 720 or 1080. It’s not bad, just an occational small stutter during panning. I’m not sure if this is due to reading the hard drive or a decoding issue, and it’s only really noticable if you know what to look for. More research required for this one, so that’s in a future update if I find anything.

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  1. March 3, 2009 at 3:15 pm

    Thanks for a tips about interlaced-noninterlaced.

  2. Dan
    September 23, 2009 at 1:35 am

    Thanks for your posts Basshead. I am interested in hearing if you have upgraded to Snow Leopard on your HTPC. I am looking for hardware for a HTPC for Plex and garageband (with guitar lessons) and was hoping to run Snow Leopard as that is what I am running on my MacBook Pro.

    Thanks again,
    Dan

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