Regular TV Stutter (1 Viewer)

Kiwi

Portal Pro
September 21, 2006
73
1
Pukerua Bay
Home Country
New Zealand New Zealand
MediaPortal Version: 1.2.1
MediaPortal Skin: Avalon
Windows Version: Win 7 x64
CPU Type: AMD Phenom II X4 810
HDD: 1 x Samsung 1TB, OCZ 50G SSD
Memory: 4GB DDR3
Motherboard: Gigabyte GA-MA770T-UD3P
Video Card: Gigabyte 550Ti
Video Card Driver:
Sound Card:
Sound Card AC3: optical out
Sound Card Driver:
1. TV Card: Hauppauge 2200 x 2
1. TV Card Type: DVB-T
1. TV Card Driver:
2. TV Card: Hauppauge 150
2. TV Card Type: Analogue
HTPC Case: Silverstone LC17
Cooling: Ninja Mini
Power Supply:
Remote: MS MCE
TV: 42" Philips LCD Full HD
TV - HTPC Connection: DVI - HDMI


Recently I upgraded my TV to a full HD Philips. As this TV supported multiple refresh rates, I enabled refresh rate changer. TV is in "PC Mode" to get 1080 without overscan.
Now when playing TV (live or recorded), I get a large stutter every 1:40s. Skipping back 15s plays the stutter part cleanly so the TS buffer & recordings are fine. MKV's playing at 23.976Hz also stutter on a regular basis. The stutter "looks like" a whole lot of repeated frames, or a whole lot of frames played quickly as if something has gone slowly out of sync and needs to catch up.

Putting the TV into "HD mode" solves the stutter :confused: , but introduces overscan :mad:
Changing the refresh rate to 60Hz also solves the repeated stutter (PC mode) :confused: The picture when panning is not as smooth at 60Hz, but is preferable to the large stutter every 1:40s.

Graphs are smooth at 50Hz with nothing indicating any problems. Graphs at 60Hz are saw tooth as expected.

Im using SAF 6 and have tried almost every possible codec combination but nothing fixes it.
Im getting the same behavior in MPC-HC although the time between stutters is shorter at 20s, which suggests that its not an MP issue alone.
Ive rebuilt PC twice with same behavior

Render graphs for 50Hz refresh & 60Hz refresh attached, plus logs while set to 50Hz.

Any ideas or suggestions welcome. :D
 

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mm1352000

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  • September 1, 2008
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    Hi Kiwi

    I'm guessing that the PC mode on your TV expects a 60 Hz refresh rate like many PC monitors operate at. Therefore you would need to alter your video card output refresh rate. I also note the info in your dxdiag info:

    Current Mode: 1920 x 1080 (32 bit) (50Hz)
    Monitor Name: Generic PnP Monitor
    Monitor Model: 1080p TV (2)
    Monitor Id: PHL151B
    Native Mode: 1280 x 768(p) (59.995Hz)

    That native resolution seems a little unusual given that you say it is full HD. In any case, as you can see the refresh rate should likely be 60 Hz to match the TV as closely as possible.

    mm

    [Edit: I should say that the difficulty is that our content here in NZ is 25p/50i, so that is probably part of the problem. We need to use some form of pulldown to match a 60 Hz refresh rate on a monitor.]
     

    Owlsroost

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  • October 28, 2008
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    I agree with mm - this looks like a problem with the TV....(unless the video card is not actually sending 50Hz to the TV - can the TV display the refresh rate etc ?)

    On some TV's the overscan on HDMI can be disabled - is there anything buried in the TV setup menus ?

    Tony
     

    Paranoid Delusion

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  • June 13, 2005
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    TV is in "PC Mode" to get 1080 without overscan.

    PC mode is a pain with philips tv's, as mm states it only give a good picture at it native 1280x768, checkout the windows desktop fonts, they are pin sharp there.

    The answer is to to go to HD mode, then in nvidia's control panel select 1080p, now under resize (later drivers 270+) change scaling to gpu, select one of the 3 pictures shown until the desktop shows correctly.

    Hope that helps.
     

    DragonQ

    Portal Pro
    August 30, 2011
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    Yeah it seems like the easiest solution would be to use "HD mode" at 50 Hz and then compensate for the overscan using the nVidia Control Panel.
     

    Kiwi

    Portal Pro
    September 21, 2006
    73
    1
    Pukerua Bay
    Home Country
    New Zealand New Zealand
    Thanks all for your suggestions & ideas.
    My understanding on native mode is that its the preferred option, however one can still choose other resolutions & refresh rates provided they are supported by the monitor / TV. The TV does indeed support 1920x1080 and at refresh rates from 24 to 60Hz. Perhaps Native Mode: 1280 x 768(p) (59.995Hz) is for the VGA input?

    Setting the video to 1920x1080 via HDMI gives a razor sharp desktop, MP gui etc, its just the regular stutter when playing video material that messing it up :(

    I also thought its probably a TV issue & got the firmware upgraded in hope but alas no difference.

    So my short term options are
    1. 1:1 pixel mapping at 60Hz with a slightly non smooth video
    2. smooth video at 50Hz but rescaled screen (not 1:1). (as an aside, in HD mode you can select 'native' mode which gets rid of overscan but this resets to off whenever the tv is turned off.:mad:

    Long term option is to get rid of the Philips & get a decent set!
    Given the most common brands in NZ are Panasonic, Sony, Samsung & LG what are users experience with TVs that play nicely with PC's?

    :D
     

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