High Frame-Rate Television

My colleagues and I from BBC Research had a fantastically successful time a couple of weeks ago at IBC, Europe's huge annual convention and conference for the broadcast community. We went there to shake things up a bit, feeling that proposals for improving the quality of television (including High Definition television itself, frankly) had concentrated too much on improving the spatial resolution (the number of pixels) while completely ignoring the temporal resolution (the number of frames per second). Television is, after all, about moving pictures.

By the end of the week, we'd shown our demonstration of the benefits of higher frame rates to hundreds of people, who almost without exception agreed that the improvements were very clear. Our criterion for success was that we'd get higher frame rates on the agenda for consideration in future TV standards, and I think we certainly achieved that. We're looking into what to do next, including finding a way to display images at frame rates higher than 120fps (the upper limit of all the contemporary displays we're aware of* - we've been using projectors designed for alternating-frame stereoscopic 3D so far), investigating how increasing the frame rate of video improves the efficiency of video codecs, experimenting with changing the temporal shape of camera shutters (simulated by down-conversion from high frame rates to conventional ones), and verifying our assertion that shooting at higher frame rates doesn't increase the visible noise in the video signal. Problem is, we really want to do some more work on 3D television, too...

We've published a White Paper on our initial work, available here. It's quite short, contains no maths, and would interest (I hope) technically-minded people from both inside and outside broadcasting. Similarities between the historical section and this post need not be pointed out. :-)

*we have CRT monitors that can go up to 200fps, but not at any kind of sensible resolution.

EDIT: We made it into the "press"! Woo! :-)
  • Posted: 25/09/08 02:01PM
  • Category: BBC

Replies

You could possibly get high framerates using simple mechanical film projectors. I wonder if film editing tables that use prisms (like this kind of thing) http://www.steenbeck.com/3-...
have fast forward functions that would go past 100fps.

To produce content that works at those kind of frame rates, you could use computer animation.
Film's certainly an option, but the use of film projectors tends to imply shuttering (and often multiple-bladed shuttering), which would probably limit the usefulness of the system. Having said that, using the fast-forward function on a film editing table hadn't occurred to us - thanks for the suggestion.

CGI as a source of content is something we've talked about, but given that cameras capable of 1080p1000 are readily available for hire, it's not something we've needed to do yet.
One big thing that would be great if it could be done is to convince the Blu-ray Disc Association or player manufacturers to add support for encoding much higher frame rates into the Blu-ray specs. The only full resolution 1080p encoding they currently allow is at 24fps. The others have to be encoded in 1080i50 or 1080i60.

Please also try to get the EBU to start recording things at higher frame rates at full HD too. Including that event that the EBU will be recording in Moscow from 12-16 May 2009.
PS: What I meant about trying to get higher frame rates at full HD into the Blu-ray specs is, they are currently in the process of adding to the specifications for stereoscopic 3D, so now might be the best time to try to get the BDA to add many more frame rates into the Blu-ray spec including ultra high ones like 1080p100 or p200 or more.
Certainly getting the support of the BDA would be a vital step in getting higher frame rates more widely adopted, but there are probably things that need to be standardised first - such as a video codec that takes full advantage of the different characteristics of high frame-rate video.

Support for higher frame rates in professional video equipment would also be vital - at present there is no standardisation of any fundamental video format faster than 60fps, and high frame-rate cameras are designed for producing relatively short clips for slow-motion replay.
Have you thought of looking at the Red cameras (red.com). Some of those are supposed to do high frame rates, though some are supposed to be 'windowed' - that might mean not full-screen or not using all of the CCD area. The Red Epic FF35 camera sounds like it might do 2K at 350fps, though it might not be out until the summer.

Perhaps someone could work with one of the camera manufacturers (like Red) on a camera where you could record the 'raw' values from the camera CCD/CMOS sensors at a very high, un-shuttered rate, so that the frame rate could be totally decided after the capture.
We have looked at the Red camera(s) - to be honest I think there are better options at the moment for the kind of high frame-rate shooting we want to do; for example, the ARRI Hi-Motion (http://www.arrimedia.com/Hi...), which can already do 2k at 1000fps - and that's a true three-chip 2k, rather than Bayer-pattern 2k.

The camera sensor technology is more or less there: NHK have already demonstrated a camera built around a 1 million fps sensor (http://www.nhk.or.jp/strl/o...). IMO the biggest technological barrier to high frame-rate production at present is the lack of a higher frame-rate infrastructure standard - something like 300fps (or higher!) HD-SDI. Which sounds like a fun engineering challenge by itself...

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