How Can I Verify Proper 24p Playback?

flexy

Diamond Member
Sep 28, 2001
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I have a old Plasma PS50A476 which is said to be excellent when it comes to 24p playback.

I don't have a blu-ray player, the TV is connected via DVI-HDMI to my PC. I have a Radeon 6450 as HTPC graphics card.

The native "recommended"resolution of the TV is 1376x768@60, this is the resolution I was playing *everything* at during the last years.

NOW I found out I can actually activate a 1920x1080@23 (or 24, or 25, or 29, 30 etc.) resolution on the PC and the TV is actually taking it. (When I do this, the Info display on the TV does indeed say 1920x1080@24). (It's only this downscaled (?) 1920 resolution which can do 24hz etc...the native resolution only works with 60hz).

However, extensive (!) tests comparing material using this 24p resolution and my normal playback native@60 does not show ANY visual difference whatsoever! I downloaded some special 24p "demo reels" and panning scenes etc...I do NOT see anything different. There is the same flicker when panning etc. in both screen modes.

Possible:

a) The TV tells me it's at 24p but in reality it is not? (How can I verify the true refresh rate?) Forcing the TV into 24p on the desktop etc...I "subjectively" don't think it's really in 24p although display info says so.
b) Media-Player Classic HC with madvr and "smooth rendering" activated in the native 60hz mode gives me the same result as forcing the TV into 24p so there is no discernible difference since madvr with that setting already gives a decent result?
 

poofyhairguy

Lifer
Nov 20, 2005
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The answer is B. The whole point of Smooth Motion in Mad VR is to blend the frames so that 24p can fit into 60hz without any interpolation. It is actually a pretty old concept, I had a similar script for avisynth back in 2009 for my 60hz LCD TV and Panasonic Plasma near the end had something very similar for mid-range models (my ST50 does it).

It is not PERFECT, but I will tell you what- I am VERY picky about this and I can't really tell a difference between what MadVR does, what my ST50 does and what a TV that can actually take 24p like my ST60 does. In fact, I would imagine that that old plasma is not a rockstar for the speed of switching refresh rates so I could see an advantage to the Mad VR method.

As far as I am concerned the only downside is something that obviously doesn't have an implication for you- Media-Player Classic HC has a WAF factor of 0%. You were already optimized, congratulations.
 
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flexy

Diamond Member
Sep 28, 2001
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thanks, very helpful!

A more general question...it is my understanding that bluray players (now talking about film) output at 1920x1080 24p.
My old Plasma has 1376x768@60hz as "native" and "recommended" when a PC is connected to it. Obviously the set scales when I would feed it 1920, a resolution which in practice it cannot even do.

The native resolution is obviously "brighter", sharper and clearer

So should I not even bother with 1920 resolution especially seeing that madvr seems to do a decent job at the native resolution? (I mean there is really no "benefit" whatsoever, in fact the display would be more blurry although that's not really visible watching a movie).
 

poofyhairguy

Lifer
Nov 20, 2005
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So should I not even bother with 1920 resolution especially seeing that madvr seems to do a decent job at the native resolution?

Yes. You always want to run a screen at its native resolution if you can. If you feed it 1080p the TV does the scaling instead of the superior computer doing the scaling.
 

flexy

Diamond Member
Sep 28, 2001
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Just as a side-note, even with the set VERY old already (manufactured late 2007) and only "HD Ready" I am still amazed about the picture quality for watching movies. (I just updated my Radeon HD4350 and put a HD6450 in the HTPC as well). I still have doubts that I would really "see" a significant improvement if I were to buy a newer, full-HD set, especially at a viewing distance of 5m as we do right now. The only gripe I have with that Plasma is that it uses quite a lot of power.