24 Hz (or multiples of) displays...

[OzzieBloke]

*snip*

Whilst it's true that our native broadcasts and DVDs are at 25 FPS, BluRays are still encoded and subsequently decoded at 24p, I'm pretty sure. I know some BluRays are encoded 25p but flagged for 50i (or 30p and 60i) for some music videos and whatnot, but all movies I've seen are 24p.

Also, I'll be running a HTPC that has 24P material, and I'll be outputting via HDMI at 1080p24 for that material.

I'll have to keep badgering the Australian reps, I think, to find out just how they handle all of this...

[MrBoylan]

Whilst it's true that our native broadcasts and DVDs are at 25 FPS, BluRays are still encoded and subsequently decoded at 24p, I'm pretty sure... unless I'm missing something.

Yes, the Blu-ray content is 24FPS, and the Australian Blu-ray players should be able to output 24p content at 1080/24p. But what I'm saying is that, for 50 Hz systems, each frame of the 24p content is typically just doubled and played exactly as is at 50 Hz instead of 48 Hz. Because you're playing back 24 fps content effectively at 25 fps, there is one extra frame per second which results in a 4% speed increase. But again this increase in speed is said to be unremarkable.

Because you guys don't need to do the 3:2 telecine encoding, you don't *have* judder, so you shouldn't actually need a Cinematic Playback feature. As long as your TV supports a 1080p/24 input, then it's possible that it converts it automatically to 50 Hz without doing any 3:2 encoding. Of course, you may get flicker this way, but you get that already since you have a 50 Hz display system. [update: actually that's probably not the case - if the player runs at 24FPS, and this is converted to 25FPS by the TV, the player would have to output the data faster in order to keep up, so never mind...].

Also, I'll be running a HTPC that has 24P material, and I'll be outputting via HDMI at 1080p24 for that material.

Should work the same as a 24p Blu-ray Disc on a player that supports 24p output.

I'll have to keep badgering the Australian reps, I think, to find out just how they handle all of this...

I'd say that's your best bet. But the Panasonic Australia web site - and the manual for the Australian version of the PZ800A TVs - say nothing about "Cinematic Playback" at all. It's possible that Panasonic Australia calls it something else, or it may just not be present in the Australian models.

It's *possible* that Panasonic will also release a version of the V10 and Z1 TVs in Australia and maybe in those they'll add a 96Hz (or 100 Hz) option for smoother flicker-free movie playback. But really you'd need to speak to a local expert at Panasonic Australia about that (or a local journalist or informed hobbyist).

Good luck!

-Chris

[OzzieBloke]

I'm not really sure how that "extra" frame per second hypothesis works unless the player itself is speeding up the content to run at 25fps upon decoding, and then doubling it to 50; if the player is outputting 24fps, that'll double to 48, which leaves a 2hz discrepancy that will introduce judder.

Thanks for you input though. I'll be researching this as time goes by...

[MrBoylan]

I'm not really sure how that "extra" frame per second hypothesis works unless the player itself is speeding up the content to run at 25fps upon decoding, and then doubling it to 50; if the player is outputting 24fps, that'll double to 48, which leaves a 2hz discrepancy that will introduce judder.

Thanks for you input though. I'll be researching this as time goes by...

Good question, and definitely one that I can't answer. To convert from 24p content to 25p/50Hz in real time, the frames would have to be buffered and re-clocked and then where would that leave the audio track unless that is also sped up by 4%? Seems like that is something that would need to be done in the player otherwise the time wouldn't add up.

I know for a fact that 24p content is converted to 25p/50i in the manner I described, when 50 Hz PAL broadcast masters are created for the UK from 24fps originals. There is no frame insertion, there is a 4% speed increase and no judder. But I don't know if the player can do the same kind of thing in real time that they do in the mastering houses. Now that you mention it, it's probably simpler to introduce a new display rate than it is to do the real time 24p to 25p conversion.

The Australian Blu-ray players do support 1080p/50Hz output, but that may only be for native 1080/50i and 1080/25p content. I don't think they convert 24p content to 50Hz output.

Hopefully you can find someone who is a bit more knowledgeable about the way it works down under. Good luck!

-CB