24 p what is it good for?

David Jimerson said:
I see sports in 60p all the time. There's not a single thing about it which interlaced would make better.

I think you're attributing the motion cadence to it being interlaced, but that's not what does it. It's the frame rate. Motion-wise, 60p and 60i (or 50p and 50i) are identical. The progressive versions simply have higher resolution and no interlace artifacts.
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Of course, you are absolutely right. Interlaced has half the resolution (or to be more precise, half the information - it trades spacial resolution partly against temporal resolution) but it is an old and widely used format. 60p (or 50p) is far out of sight as a TV norm in Europe. Don't know about the states but can't be that different. And the cinema norm is (still) 24f/s so nowhere to go with the high frame rate.

And, so we are back with to actual subject, why not keep the formats that have a long track-record (like 25p/50i, 30p/60i)? I appreciate new formats but I still need the possibility to work according to the standards (eg. for commissioned TV work) and that's where the GH2 falls flat for me. It can do 50i, OK, but I loose data-rate and quality.

Best, g
 
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But the temporal resolution comes entirely from the number of exposures -- moments in time -- taken/displayed per second. 60/50p takes/displays the same number as 60i/50i. They simply don't have to give up the spatial resolution to do it.

Even if in Europe there is no progressive broadcast, it still makes sense to record sports in 50p. It's an easy conversion to 50i, and you start with a better source. Plus, you have better material for archive and for web display, or other delivery methods besides broadcast.
 
glnf said:
And, so we are back with to actual subject, why not keep the formats that have a long track-record (like 25p/50i, 30p/60i)? I appreciate new formats but I still need the possibility to work according to the standards (eg. for commissioned TV work) and that's where the GH2 falls flat for me. It can do 50i, OK, but I loose data-rate and quality.
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It's not like 25p or 30p are going away. But interlaced was only ever a necessary evil, so as technology makes the evil unnecessary, there's no reason to keep it around. As I said, there's no visual advantage to it and numerous disadvantages compared to the same acquisition rate in progressive.

24p, of course, exists entirely because 24 fps for cinematic film DOES have a long, long, long track record, far longer than any interlaced standard. (And 30p is a weird hybrid standard, anyway.)
 
David Jimerson said:
It's not like 25p or 30p are going away. But interlaced was only ever a necessary evil, so as technology makes the evil unnecessary, there's no reason to keep it around. As I said, there's no visual advantage to it and numerous disadvantages compared to the same acquisition rate in progressive.

24p, of course, exists entirely because 24 fps for cinematic film DOES have a long, long, long track record, far longer than any interlaced standard. (And 30p is a weird hybrid standard, anyway.)
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Of course. Interlaced is an outdated legacy format that causes a lot of headache and worse still, it is broadcasting standard. But when you say 25p/30p won't go away - that's where Panasonic thinks differently. They obviously either want to be ueber-sexy or they want to force people like me to buy the AF101 but 25p is gone.
 
If you say that simply because of the GH2, I refer to you what Barry said above -- the GH2 isn't a video camera. It's a still camera which shoots video. What it has or doesn't have really has no bearing on much of anything as far as standards.

25p is not disappearing from video cameras. (Besides, it hasn't been around for very long.)
 
DVD MPEG is inherently interlaced. It may be acting as a container for progressive material, but it is field-based MPEG.

Edit: I should qualify that by saying "official specification DVD MPEG2"
 
It depends on what you mean by "field-based."

They contain instructions -- flags -- which direct a DVD player to insert interlace fields where necessary, IF necessary, but the files themselves are genuinely 23.976, progressive. They do not contain the extra interlaced frames. They are not themselves interlaced files.
 
This is quite interesting topic, and I don't wanna digress it any further. Yes Hollywood movies r recorded in DVDs with 24p format. It's up to the dvd player that determines 3:2 pulldown or not. Ok let's move on.

Watching high definition movie in 24p format on 60Hz HDTV creates more awkward motion jitter because 60 is not a multiple of 23.976. Watching it on 23.976Hz HDTV should reduce the motion jitter. Each frame is played in same duration. Affordable consumer HDTVs outputting at 23.976Hz have been on the market for only a couple of years. As more people buy 23.976Hz HDTVs, the claimed 24p's ugly jitter issue will be a moot point.
 
To quote David Newman, Cineform CTO, who knows of what he speaks: "The confusion comes from the DVD standard which has no progressive mode, it is only encoding fields with repeat flags that a progressive DVD player uses to reconstruct the source 24p signal from the 60i data on disk. "

The source material may be progressive, but the data on the disk itself is field based. If you look at a pro-level encoder such as Procoder, there is no progressive (i.e. frame-based) encoding option available for DVD MPEG.
 
GrahamH said:
To quote David Newman, Cineform CTO, who knows of what he speaks: "The confusion comes from the DVD standard which has no progressive mode, it is only encoding fields with repeat flags that a progressive DVD player uses to reconstruct the source 24p signal from the 60i data on disk. "

The source material may be progressive, but the data on the disk itself is field based. If you look at a pro-level encoder such as Procoder, there is no progressive (i.e. frame-based) encoding option available for DVD MPEG.
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Graham, I produce DVDs for a living. I know what's on them. It's 24p, not 60i. Yes, that's what's on the disc. The .vob files themselves are 24p.
 
I think all of you that want 25p on the GH2 should contact Panasonic directly, put some true consumer pressure on them.
 
stonebat said:
Watching high definition movie in 24p format on 60Hz HDTV creates more awkward motion jitter because 60 is not a multiple of 23.976. Watching it on 23.976Hz HDTV should reduce the motion jitter. Each frame is played in same duration. Affordable consumer HDTVs outputting at 23.976Hz have been on the market for only a couple of years. As more people buy 23.976Hz HDTVs, the claimed 24p's ugly jitter issue will be a moot point.
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We've all been watching 24 fps material on 60 hz screens our entire lives. If you've ever watched a movie on TV, you've done so. Do you notice problems with jitter?
 
back to 24p and its proper usage on gh2. here is a video somebody on dvxuser posted http://www.youtube.com/watch?v=SX5vYx-4yRU
its high motion action shots. i am assuming he shot 24p cinema mode though do not know for sure. you can see strobing of guys flying thru air. to me this is a totally normal error as shots like this should be shot on 60p or 60i not 24p.
thoughts?
 
Depends entirely on the look you're after. If you want a live look, then it should be 60. If you want a cinematic look, then it should be 24.
 
David Jimerson said:
We've all been watching 24 fps material on 60 hz screens our entire lives. If you've ever watched a movie on TV, you've done so. Do you notice problems with jitter?
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I do but I come from PAL land, 24p material vs 24p speed up to 25p on a non-native 24p set is bad, really noticeable on pans and credit screens.

I'm glad 24p native sets are affordable nowadays
 
rubberbandito said:
back to 24p and its proper usage on gh2. here is a video somebody on dvxuser posted http://www.youtube.com/watch?v=SX5vYx-4yRU
its high motion action shots. i am assuming he shot 24p cinema mode though do not know for sure. you can see strobing of guys flying thru air. to me this is a totally normal error as shots like this should be shot on 60p or 60i not 24p.
thoughts?
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It's full of ghosting, I guess they must have done something wrong considering framerate somewhere in post?!
 
Barry_Green said:
lpowell said:
...all NTSC DVD content is recorded in 59.94i interlaced format, with 3:2 pulldown used to encode 24p movies:

http://www.dvddemystified.com/dvdfaq.html#3.8
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Sorry, that's just not true. I've been authoring and publishing DVDs in native 24p for years and years. You absolutely positively do not have to author a 60i MPEG2 file, you can create and export a 24P progressive MPEG-2 file and author that to DVD as 24P. The DVD player itself takes care of adding pulldown or not.
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It was remarkably difficult to find unambiguous documentation on this issue - not even the DVD Forum publishes complete technical details of the MPEG-2 format recorded on DVD discs. Here's what they do provide:

http://www.dvdforum.org/mi-general.htm

I finally resorted to examining the DVD encoding options and documentation in the MainConcept Codec Suite 5.1 plug-in for Adobe CS5. This encoder provides operator access to virtually every modifiable parameter in the MPEG-2 encoding process. Even after sorting out how it actually works, I still find it confusing and counter-intuitive:

In the MPEG-2 files, there are two tags used to describe the progressive and/or interlaced properties of the video stream:

Picture Structure: either Interlaced or Progressive
Telecine/Pulldown: either none, 3:2, 2:3, or 2:2

If the source video is already interlaced (e.g.. pure 50i or 60i), the interlaced fields are simply encoded in order. Picture Structure is marked as Interlaced and Telecine/Pulldown is set to None. What's confusing is that this format is called "hard telecined" when the interlaced video contains a pre-telecined 24p movie with pulldown permanently built-in.

If the video is progressive and does not use pulldown (e.g. 50p or 60p), each frame is encoded progressively. Picture Structure is marked as Progessive and Telecine/Pulldown is set to None. However, this MPEG-2 format is not used on DVD's.

If the video is progressive and uses pulldown (e.g. 24p), each frame is encoded as a pair of progressive fields, and two tags are set to indicate the field order and whether to repeat the first field. In 3:2 pulldown mode, the sequence of frame tags tells the DVD player exactly how to expand the 24p field sequence into a 60i video stream. This is called "soft telecined" video. What's surprising is that even though the video is tagged as a sequence of fields, it's not 60i, it's effectively a 48i video stream!

The way DVD encodes 25p and 30p videos is also surprising. Instead of storing these videos as progressive frames, each frame is encoded as a pair of progressive fields with a 2:2 pulldown pattern. The two frame tags are set to indicate how the 50i or 60i stream of fields should be reconstructed into a 25p or 30p sequence of progressive frames. A DVD player with progressive output can thus reproduce the 25p or 30p video exactly as if it had been recorded as progressive frames.
 
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stonebat said:
This is quite interesting topic, and I don't wanna digress it any further. Yes Hollywood movies r recorded in DVDs with 24p format. It's up to the dvd player that determines 3:2 pulldown or not. Ok let's move on.

Watching high definition movie in 24p format on 60Hz HDTV creates more awkward motion jitter because 60 is not a multiple of 23.976. Watching it on 23.976Hz HDTV should reduce the motion jitter. Each frame is played in same duration. Affordable consumer HDTVs outputting at 23.976Hz have been on the market for only a couple of years. As more people buy 23.976Hz HDTVs, the claimed 24p's ugly jitter issue will be a moot point.
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i'm following and reading about this problem of watching 24p footage on my 60htz monitor..
can you please recommend a good affordable computer screen that will show this properly?
 
roei z said:
i'm following and reading about this problem of watching 24p footage on my 60htz monitor..
can you please recommend a good affordable computer screen that will show this properly?
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In pal land 50 hz or 100 or 200 hz is standard in tvmotiors. Not 60 hz, 60 hz is computer monitor and thats why we need 25 p for to be abel to watch it on tv.
 
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