International standards

CharlesPapert

CharlesPapert

Director of Photography
A friend asked if he makes a video clip in the US and it needs to screen in an auditorium in Denmark off a laptop, does he need to do any converting of the file for it to play properly. I realized I don't know the answer to this. Can anyone help? I know there is still the 50hz/60hz thing but how does this reflect in a master clip--I get 25p vs 24p, but if for instance he is using a 29.97p or 59.94p timeline does that need to be converted to something other?
 
Yes got that on 24 being standard. The original footage wasn't 24 I believe so I was trying to learn what else they needed to master in. Do they have 50p like we have 60p? For instance, what does a streaming stick output in Europe (in US it is 60p unless it is flagged to output 24p for a given program). So what would happen if you streamed a 60p Youtube feed from your phone to a European TV?
 
Right so 25p or 50i is the transmission standard but most DTV sets make 50p out of 50i as far as I know.

eveyone else outside the US is used to converting a US standard. So 23.98 would just be sped up a bit to 24 or even 25.

you’re trying to anticipate a conversion. I would just deliver native and let them take care of the conversion. It’s routine.
 
Does "let them take care of the conversion" mean the hardware (laptop playing back file, projector) will just do it automatically?
 
As far as I know 50i 60i was from the time when TV stations were analog and normal electricity but digital TV doesn't necessarily follow this story, the system is like a computer.Do these principles still have to be observed in broadcasting stations?
 
I believe a lot of the hardware that transmits DTV is still 50i. Even though a lot of DTV will the concert it back to 24.

Remember a lot of the rest of the world don’t do cable. It’s broadcast or streaming.

Yes Charles, I would imagine it would play and convert if needed. Best would be to stick to one of the standard frame rates though. 24 would be best and most universal. Otherwise 50/60 is ok too.
 
I know nothing.

What I do know is that on may last film we had a 'telly' and it did not work until someone did some work with the redbyte box.

So automation is not guarenteed success.

This was the fx9 and i still dont understand if it records 24, 23.98 and the output might be psf.

A different 'telly' did work. or maybe only after the red box!
 
by Redbyte box do you mean a Decimator, or a Decimator MD-HX or Cross? The Decimator doesn't do any format conversion per se, other than HDMI type. If it was psf to p or format conversion it would have been an MD-HX or MD-Cross.
 
Sorry cp - i do not know - a bigger modern red box - not my old one.

i just saying that not everything works - so testing is good.

even send a 2s clip to me :)
 
Sounds like an MD-HX or Cross. I have long recommended that everyone in video production should have one of these in their kit. It's probably the single most useful multi-purpose converter out there. SDI to HDMI conversion in both directions, 1x4 SDI distribution amp (if you run out of outputs on your camera, for instance), and scaling of all SD and HD resolutions up and down including psf to progressive. Not bad at $295, but If you can spring for another $200, you can future proof by upping to the 12G Cross model which is a 4K scaling engine.

As I think we had discussed in another thread Sam, the company name changed from Redbyte to Decimator Design after the 1st Gen Decimator was introduced, so all subsequent devices including the Decimator 2 bear that name.

stacks-image-9ef912b.jpg

If this was me traveling and having to project off an unknown laptop I would absolutely be taking an MD-HX with me, but I don't know if I can convince my friend to get one...!
 
CharlesPapert said:
A friend asked if he makes a video clip in the US and it needs to screen in an auditorium in Denmark off a laptop, does he need to do any converting of the file for it to play properly. I realized I don't know the answer to this. Can anyone help? I know there is still the 50hz/60hz thing but how does this reflect in a master clip--I get 25p vs 24p, but if for instance he is using a 29.97p or 59.94p timeline does that need to be converted to something other?
Click to expand...

Ideally to avoid dropping / repeating frames during playback you want the Laptop/Projector to be able to display a refresh rate that matches the FPS of the original material you are rendering.
1) What the FPS of the original clips (or the majority of original clips)?
2) Get him to plug the Laptop to the Projector, and see what Refresh Rate are available, ideally looking for the refresh rate of #1. Get him to set that refresh rate when playing your video.
 
A side thought. If 'his' file is 23.98 he could make a 24p version (minor speed shift) or a 25p version (less minor speed shift but OK) and then an interpolated 30p version

these should all be easy to produce in Resolve.

But ultimately I cant really help :(
 
24 --> 25 is still not a great idea. When played back on a 50hz display you will get either:
- 2 frame repeats a second, or you
- do the old fashioned PAL Speed up (4%) so the runtime will be shorter and the audio pitch will need adjusting

Seriously, just check what frame rate the original clips are and then see if the Laptop/PJ refresh rate can be set to that (or an exact multiple), eg if the original is 25fps, and the PJ / Laptop can do 50hz you are good to go. I would be surprised if the Laptop/PJ can't do all the relevant refresh rates including 23.976 / 24 / 25 / 29.97 / 30 / 50 / 59.94 / 60hz.
 
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jmone said:
24 --> 25 is still not a great idea. When played back on a 50hz display you will get either:
- 2 frame repeats a second, or you
- do the old fashioned PAL Speed up (4%) so the runtime will be shorter and the audio pitch will need adjusting

Seriously, just check what frame rate the original clips are and then see if the Laptop/PJ refresh rate can be set to that (or an exact multiple), eg if the original is 25fps, and the PJ / Laptop can do 50hz you are good to go. I would be surprised if the Laptop/PJ can't do all the relevant refresh rates including 23.976 / 24 / 25 / 29.97 / 30 / 50 / 59.94 / 60hz.
Click to expand...

Clip is being made in US and shown in Europe so the clips will not be in a multiple that will fit in 50hz. I think I'm just going to loan him an MD-HX and not think about it any more. Ha.
 
There is not much to think about. This is not going to broadcast so there is nothing that says it has to be 50hz. Most display gear (outside of the US) can support all the major refresh rates, not just 50hz. He will just need to set the laptop's refresh rate to whatever the FPS of the material that was shot and rendered. It does not get much simpler, but he should check to be sure.

The key to avoid dropped/repeated frames is to always keep Acquistion = Render = Playback. I'm in Oz (aka PAL Land) and while broadcast is a static 50hz, when using the PC to playback to the TV/PJ it dynamically changes the refresh rate to match (eg 23.976 / 24 / 50 etc etc).

Even my Apple TV box auto changes refresh rates when streaming to match the FPS of the material being viewed.
 
thanks jmone. Appreciate your chiming in. I'm a little confused however because it sounds like you are saying don't worry, the laptop will do the necessary conversion, but then you also suggest that certain frame rates will result in either a speed change or dropped frames. If it's really going to save him any issues, it seems like it would be better to convert the material to something that is more directly compatible with 50hz while still here, or at least have both versions with him so he can see which plays best?
 
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