23,976 FPS / 24p

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23,976 FPS / 24p

Hi,
I am using my Mac Mini on a Panasonic plasma (1280/720) it looks great. But when I watch a movie with a frame rate of 23,976 / 24p There is some judder. The TV is 24p compatible.

So my question is: How to enable the 23,976/24p frame rate? Now i only have the option between 50/60Hz

Thanks in advance.

Mini 1,83 c2d 1GB 80GB (standard)

Posted on May 26, 2008 4:06 AM

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Answer 1

BSteely

Level 5

7,643 points

May 26, 2008 9:42 AM in response to Oxi

Try SwitchRes X. You could also try DisplayConfigX, but you have to pay the registration fee first with DisplayConfigX. SRX allows you try it for free to see if it will work. Then you pay the registration fee if you feel you are getting your money's worth.

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Answer 2

Oxi Author

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May 28, 2008 4:44 AM in response to BSteely

Yea,
I tried those two apps, but every time I alter the settings my display goes black. Its pretty hard to get the right settings, and I don't seem to find the standard settings for 1280x720/24p anywhere on the net. Do you know where to find them?

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Answer 3

May 28, 2008 6:16 AM in response to Oxi

Oxi wrote:
Yea,
I tried those two apps, but every time I alter the settings my display goes black. Its pretty hard to get the right settings, and I don't seem to find the standard settings for 1280x720/24p anywhere on the net. Do you know where to find them?

I have seen reports from people who have got 1920x1080/24p working thanks to SwitchResX but as you say it is hard work.

Have a look at this thread for some tips.

http://www.avsforum.com/avs-vb/showthread.php?t=751713

One important tip is that it is important to use 23.976 rather than 24.000. While many people call it simply 24p for simplicity it is actually 23.976 and if you use 24.000 it will result in a judder every approximately 41 seconds.

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Answer 4

Oxi Author

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May 28, 2008 7:56 AM in response to John Lockwood

Thanks for that!
Its a good starting point. Now i know a lot more. But it still would be nice if someone posted there settings for standard 1280x720/23,976 😉

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Answer 5

BSteely

Level 5

7,643 points

May 28, 2008 9:49 PM in response to Oxi

In SwitchRes X, you can use the GTF (Generalized Timing Formula) to fill in all the parameters. All you enter is 1280, 720 and 23.976 and SwitchRes X will do the rest.

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Answer 6

Oxi Author

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May 30, 2008 3:05 AM in response to BSteely

Thanks for the reply.
When I do just that my screen goes black....?? The TV supports 24p. Strange right?

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Answer 7

BSteely

Level 5

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May 31, 2008 7:37 AM in response to Oxi

Would you mind posting your TV's model number? I'd like to read the user manual if I can find it online.

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Answer 8

Oxi Author

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Jun 1, 2008 3:50 AM in response to BSteely

Hi B. Steely,
My tv is a Panasonic TH-37px80e. You can download the specs and manual from their site (I also did that before I brought it) Picture quality is just lovely in combination with osXbmc. Just want to display the movies at 23,976 Fps or double 47,952 Fps. Double seems pretty close to PAL standard 50 Hz. Hope you can help cause I am on a dead track I think....

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Answer 9

BSteely

Level 5

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Jun 1, 2008 8:19 AM in response to Oxi

Looking over the user manual for your TV, I can only find a 24p reference for the component video input. All references to making a PC connection specify a range of 59Hz to 86Hz for the vertical scan. Based on that, I'm not sure it's going to work to drive the TV at 24p from the mini.

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Answer 10

Oxi Author

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Jun 1, 2008 11:49 AM in response to BSteely

All HDMI inputs are also 24p (23,976Hz) compatible. This is a sure thing.
My Mini is also connected via DVI-HDMI.

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Answer 11

BSteely

Level 5

7,643 points

Jun 1, 2008 9:47 PM in response to Oxi

My apologies. I do see that I read the user guide incorrectly and that 1080p/24 is supported over HDMI. In that case, try the following timing in SwitchRes X and see if you can get a picture:

Pixel clock: 74.25 MHz
Horizontal Active: 1920 pixels
Horizontal Front porch: 638 pixels
Horizontal Sync width: 44 pixels
Horizontal Back porch: 148 pixels

Vertical Active: 1080 lines
Vertical Front porch: 4 lines
Vertical Sync width: 5 lines
Vertical Back porch: 36 lines

This should result in a 24 Hz vertical scan rate. If you want to try and achieve 23.976 Hz, you can enter that in place of 24 and then see if the mini can successfully synthesize the resulting pixel clock or not. Good luck.

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