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unfrostedpoptar

macrumors regular
Original poster
Jan 29, 2010
173
11
I hope someone can clear this up. I know if you're using a Blu-ray player attached to a TV via HDMI, it can adjust the frame rate to match the content so movies are at 24 FPS and TV at 60.

What happens when I'm playing video on my rMBP? I have files that show a frame rate of 24 (actually 47.952024) and others 29.970030. If I play these in VLC or Quicktime, what rate is it displaying on the LCD panel? How can I tell? Is it different in full-screen?

What about when I output to my Dell u2711 over DP or HDMI? Do these dynamically adjust the rate? Is the player doing interpolation to match the monitor rate? Again, is there some place I can see this info?

I've searched all over the place and haven't found any info on this topic.

Thanks for any info!

David
 
The reason you haven’t found anything is because they don’t have a frame rate.

The pixels change colour when they are told by the GPU therefore if you are playing a 24fps film it will playback at 24fps (if your computer can handle it). The same is true of other frame rates.

Aslong as the signal is digital the frame rate should be the same as the source.

If you mix in an analogue signal things start to get a bit tricky.
 
Thanks for the reply. I understand all those issues, which is why I'm concerned. I just don't have a clue what the Mac is doing about it or how to find out!

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The reason you haven’t found anything is because they don’t have a frame rate.

The pixels change colour when they are told by the GPU therefore if you are playing a 24fps film it will playback at 24fps (if your computer can handle it). The same is true of other frame rates.

Thanks. That would make sense for the internal LCD panel. But what about when I'm driving an external monitor? Maybe I'm thinking composite/VGA and this doesn't even make sense for Displayport. But I thought DVI/HDMI are variable frequency with sync, like the older, analog video standards.
 
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