Recent movies filmed on digital video have the problem that the exposure time is much less than the frame gap. So action scenes look like flick-books. Gladiator had this issue, as well as most of Michael Mann's recent output. A higher framerate will make action really flow.
James Cameron champions faster film projection rates (from 24 to 60 fps)
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Re: James Cameron champions faster film projection rates (from 24 to 60 fps)
#82Earlier quoted context omitted.
Very interesting. Thanks for the detail. I guess the fixed GOP structure must be limited to HDV (MPEG-4). That flexibility is pretty awesome. For what it's worth, I suspect what you describe (720p60 @ 6Mbps) is more than fine for most people. In other words, Cameron's idea that people will be going to theaters because of magical picture quality seems like wishful thinking. I suspect people go to theaters because they…
HDV has nothing to do with H.264, or any of the MPEG-4 standards for that matter.
You're absolutely right. I see that HDV is encoded with the H.262/MPEG-2 Part 2 compression scheme.
Re: James Cameron champions faster film projection rates (from 24 to 60 fps)
#83A video comparing 24 fps to 60 fps (In video games, where the difference is higher) http://mckack.tumblr.com/post/3535190601/60fps-vs-24fps
I really must be "blind". I can see the difference side-by-side (especially the moving ball) but the difference is so slight. Even 15fps looked fine to me. If you showed them to me back-to-back, I don't think I could tell the difference. Which is frustrating to me, because I know the difference but I wish I could see the difference. I feel like my eyes are failing me.
This is watching the downloaded avi.
Re: James Cameron champions faster film projection rates (from 24 to 60 fps)
#84going to 48 would be fine, but I really want digital theaters at minimum of 4K and keeping the brightness on the bulb turned up to where it is supposed to be (not lower to same money)
Re: James Cameron champions faster film projection rates (from 24 to 60 fps)
#85Earlier quoted context omitted.
Assuming the bitrates are the same, 48fps will require 80% of the bandwidth needed to handle 60. To the best of my knowledge, H.264 only supports two GOP structures (short = 6 frames / long = 15 frames), both of which operate independently from the playback speed. In other words, a short GOP setting produces 8 blocks per second running at 48, and 10 per second running at 60. Assuming a constant bitrate (I know, I kno…
> "To the best of my knowledge, H.264 only supports two GOP structures (short = 6 frames / long = 15 frames), both of which operate independently from the playback speed. In other words, a short GOP setting produces 8 blocks per second running at 48, and 10 per second running at 60. Assuming a constant bitrate (I know, I know), the throughput of the entire system needs to increase by an additional 20% to handle 60."…
Dude, chill. Also, read.
Accepting that I was mistaken about the rigidity of h.264 (a possibility I acknowledged up front), and assuming that you DID establish a GOP structure of 6 frames (at a constant bit rate) shooting for one minute at 48 fps would produce 80% of the data generated by shooting at 60fps.
Indeed, this ratio would be true if you used no compression at all. The point was that in a fixed GOP scheme (again, at a constant bitrate), the difference in FILE SIZE would increase with the difference in frame rate, so the idea that file sizes for 60 fps material would only be marginally larger than those for 48 fps seemed mistaken.
My only mistake was in assuming that the GOP is fixed in h.264. I agree that "you don't get from frames to final bitrate by dividing frame rates by GOP size." But then again, I never said you did.
Re: James Cameron champions faster film projection rates (from 24 to 60 fps)
#86Earlier quoted context omitted.
That doesn't seem like it could be true. The film is rolling through the camera, and if the shutter were open continuously, the entire film would be a vertical blur of light. The shutter would open and close once per frame, so the film can be advanced. The actual shutter speed of a camera shooting 24 fps would be much faster than 1/24 s.
Correct. There's a simple formula for that: http://en.wikipedia.org/wiki/Shutter_speed#Cinematographic_s...
Oh, cool. The linked article about the rotary shutter also has a great animation showing how the camera works:
Re: James Cameron champions faster film projection rates (from 24 to 60 fps)
#87It's about damn time. I've never understood the rush to increase resolution and 'dimensions' when simple camera pans fundamentally do not work, and never have.
Re: James Cameron champions faster film projection rates (from 24 to 60 fps)
#88Earlier quoted context omitted.
Seems like you wouldn't count on the TV to do this work. Instead, you'd shoot at 48, then convert to 60 before delivery, in the same way that TV shows shot on film and edited at 24p subsequently convert to 25 for PAL markets and 29.97 for NTSC.
Problem is, while you can devise ways of converting 24p to interlaced 29.97, getting from 48 progressive frames to 60 progressive frames isn't obvious to me at all. You'd have to add a frame every 4 frames. This would likely ruin the whole large framerate experience.
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Re: James Cameron champions faster film projection rates (from 24 to 60 fps)
#89There are some televisions that have the ability to interpolate a 24fps format and produce an apparent higher frame rate. Watching sports on these televisions is great, but I tried watching Iron Man on one and it made it look like an after school special. I believe this is colloquially know as the 'soap opera effect'. Google for 'samsung soap opera effect'.
I watch everything like this on my Samsung television (this is a 2009 model so I assumed nearly all new TVs have interpolation+high refresh rate.) My favorite is watching old movies on bluray, combined with this it is like you are actually there.
Re: James Cameron champions faster film projection rates (from 24 to 60 fps)
#90Earlier quoted context omitted.
That is because a game's frame is rendered at one absolute time point, while a movie's frame is like a photograph taken with a shutter speed of 1/24th: it includes the motion data of that whole time interval, it contains motion blur, and it's smooth from one frame to the next. That's why a game at 24fps looks bad, but an (action) movie at 24fps looks good.
That doesn't seem like it could be true. The film is rolling through the camera, and if the shutter were open continuously, the entire film would be a vertical blur of light. The shutter would open and close once per frame, so the film can be advanced. The actual shutter speed of a camera shooting 24 fps would be much faster than 1/24 s.
You're right about the continuous roll. Film actually moves through the gate incrementally. There's a really neat mechanism that closes the shutter and advances the film to the next frame in one elegant move. But while the film is exposed, it's exposed for a fraction of a second. Meaning that any motion occurring within that second will register with a blur in that particular frame.