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576p is not HD

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Thanks Davo, so why wouldn't the film studios produce their new Blu-Ray/HD-DVD HD film transfers in 1920x1080 24PsF?

Do you know of any 24p displays? I do but they are $30-35K CRTs.

I think for format commonality it will be 1080/30p/60i (in the USA) and 1080/25p/50i in 'PAL' countries.

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I should also add that the T2 manual is a bit confusing. You don't get jaggies from film transferred as interlace, only from interlace video originated material.

And the reason why the format commonality will not include 24P is the ongoing, and highly unproductive, film vs video format war that has raged for at least 20 years.

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Yup, either film or a digital video camera capable of doing 24/25p (I think The 4400 was done this way?).

Not sure about The 4400 (IMDB doesn't have any tech specs), but this is definitely the right way to do 1080@50i - it is then capable of being 'cleanly' deinterlaced for progressive display, and 'degrades' gracefully to 1080@50p (albeit at half the possible frame rate).

- Miles.

The process used by 1080i video cameras to record 1080 25P is called 'progressive segmented frame' (psf). The camera captures the whole image off the CCD each 25th of a second, although, usually, an electronic shutter limits the capture time to a 50th, to reduce blur. The resulting image is split into two fields and recorded as interlace, i.e. 1080i.

I think the 4400 was shot on video using 24p, (i.e. 29.97 psf, a sort of reverse video 3:2 pulldown).

Some one will correct me if I'm wrong here, but I think most progressive displays don't deinterlace 1080i to scale it. They simply treat each field as a progressive frame and scale the 540 lines to the display res.

Sony are planning HDCAMs with 1080i/150hz and 1080i/180hz formats to aid image quality particularly for fast motion like sports coverage instead of trying to do progressive formats. Their consumer display technology is focussed on 1080p at the moment though since the internal digital deinterlacing is a seemless process.

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Yup, either film or a digital video camera capable of doing 24/25p (I think The 4400 was done this way?).

Not sure about The 4400 (IMDB doesn't have any tech specs), but this is definitely the right way to do 1080@50i - it is then capable of being 'cleanly' deinterlaced for progressive display, and 'degrades' gracefully to 1080@50p (albeit at half the possible frame rate).

- Miles.

The process used by 1080i video cameras to record 1080 25P is called 'progressive segmented frame' (psf). The camera captures the whole image off the CCD each 25th of a second, although, usually, an electronic shutter limits the capture time to a 50th, to reduce blur. The resulting image is split into two fields and recorded as interlace, i.e. 1080i.

I think the 4400 was shot on video using 24p, (i.e. 29.97 psf, a sort of reverse video 3:2 pulldown).

Some one will correct me if I'm wrong here, but I think most progressive displays don't deinterlace 1080i to scale it. They simply treat each field as a progressive frame and scale the 540 lines to the display res.

Sony are planning HDCAMs with 1080i/150hz and 1080i/180hz formats to aid image quality particularly for fast motion like sports coverage instead of trying to do progressive formats. Their consumer display technology is focussed on 1080p at the moment though since the internal digital deinterlacing is a seemless process.

Don't you mean 1080/50p and 1080/60p? The rate you metion will be bloody bandwidth hungry.

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Don't you mean 1080/50p and 1080/60p? The rate you metion will be bloody bandwidth hungry.

No, I most definitely don't. We are talking an all new recording format. I don't know a time frame on this as Sony has not divuluged one yet.

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Don't you mean 1080/50p and 1080/60p? The rate you metion will be bloody bandwidth hungry.

No, I most definitely don't. We are talking an all new recording format. I don't know a time frame on this as Sony has not divuluged one yet.

The formats you describe are what is called 'Super slow motion'. That is record at mutples of the frame rate and then replay at 1080i/25 frames, and you have proper slow mo, not step frame slow mo.

Sony have in the works a 1080/50p camera which will be twice the bandwidth with really high quality images for post production. The problem is it will be so good the old 'film die hards' won't like it because there will be no 'flicker'.

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Don't you mean 1080/50p and 1080/60p? The rate you metion will be bloody bandwidth hungry.

No, I most definitely don't. We are talking an all new recording format. I don't know a time frame on this as Sony has not divuluged one yet.

The formats you describe are what is called 'Super slow motion'. That is record at mutples of the frame rate and then replay at 1080i/25 frames, and you have proper slow mo, not step frame slow mo.

Sony have in the works a 1080/50p camera which will be twice the bandwidth with really high quality images for post production. The problem is it will be so good the old 'film die hards' won't like it because there will be no 'flicker'.

The presentation I saw on 1080i/150/180 did not speak of super 'slowmo', just better image quality. No mention was made of 1080p cameras being developed for professional use.

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Their consumer display technology is focussed on 1080p at the moment though since the internal digital deinterlacing is a seemless process.

It might be seamless for film originated, or 24/5 PsF, but it's not for 1080 50i.

Sort of begs the question why Sony would focus on 1080P for domestic displays when are they are so keen on 1080i for production? Why interlace to de-interlace?

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Their consumer display technology is focussed on 1080p at the moment though since the internal digital deinterlacing is a seemless process.

It might be seamless for film originated, or 24/5 PsF, but it's not for 1080 50i.

Sort of begs the question why Sony would focus on 1080P for domestic displays when are they are so keen on 1080i for production? Why interlace to de-interlace?

Good question, perhaps they feel it's easier to work with. Owen is the expert on the 1080i/p deinterlace question, but my understanding is that quite flawless for 1080i 50/60, the feedback on Sony's 1080p Qualia rear pro seems to indicate this. Check it out on AVSForum..

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Their consumer display technology is focussed on 1080p at the moment though since the internal digital deinterlacing is a seemless process.

It might be seamless for film originated, or 24/5 PsF, but it's not for 1080 50i.

Sort of begs the question why Sony would focus on 1080P for domestic displays when are they are so keen on 1080i for production? Why interlace to de-interlace?

Good question, perhaps they feel it's easier to work with. Owen is the expert on the 1080i/p deinterlace question, but my understanding is that quite flawless for 1080i 50/60, the feedback on Sony's 1080p Qualia rear pro seems to indicate this. Check it out on AVSForum..

The reason I say it's not flawless is because once something is shot interlaced it cannot really be de-interlaced. Deinterlacing is a bit like interpolating to a higher resolution.

The easiest way to explain this is to imagine (theoretical) material shot in 1080 50P. To convert it to 1080 50i you have to drop half the vertical resolution (every alternate line) from each frame. When the image is static that's OK, becasue the two fields will still combine to produce a full resolution image. But when the image moves you've only got half the resolution, because the fields don't line up anymore.

The other problem with this theoretical conversion is that the refresh rate of 1080i is 50Hz but each field is only refreshed every 25th of a second. If the 1080P original has detail that resides on only one line that line would flicker annoyingly at 25Hz, so the conversion would need to soften the image to avoid this.

So, as you can see, a theoretical conversion of 1080p to 1080i will result in up to a 50% loss of potential resolution.

The only "flawless" 1080i to 1080p conversion is 1080 25PsF. If 25fps is what is to be displayed it would make a lot more sense to record and compress it as 25 frames progressive.

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I should also add that the T2 manual is a bit confusing.  You don't get jaggies from film transferred as interlace, only from interlace video originated material.

I think what they're referring to is the difference between the old tranfer on the ultimate dvd to the new transfer on the extreme dvd

that would make perfect sense

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The reason I say it's confusing is that what they say is correct, but not in the context of a telecine transfer, e.g:

"Progressive Segmented Frames" means that each frame of video is created progressively , just like film."

Wrong, PsF means it's recorded as 1080i, i.e. interlace.

"With interlaced scanning the video frame is scanned as two separate fields, thus:

* Top field (odd scan lines) scan line numbers 1, 3, 5, 7, 9, 11, etc. followed by

* Bottom field (even scan lines) scan line numbers 2, 4, 6, 8, 10, 12, etc.

* The video frame does not always capture the exact same content that a film frame contains

* Motion does not appear as smooth; diagonal lines are jagged"

This would be true in the case of a film camera and a video camera recording the same scene, but this is not the case here. A telecine will capture both fields from the same frame. Jaggies are an artifact of interlaced origination, not interlaced telecine. You shouldn't get jaggies on either an interlace or 24 PsF transfer.

I know I'm being a bit pedantic, but THX should explain things correctly.

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The reason I say it's confusing is that what they say is correct, but not in the context of a telecine transfer, e.g:

"Progressive Segmented Frames" means that each frame of video is created progressively , just like film."

Wrong, PsF means it's recorded as 1080i, i.e. interlace.

"With interlaced scanning the video frame is scanned as two separate fields, thus:

* Top field (odd scan lines) scan line numbers 1, 3, 5, 7, 9, 11, etc. followed by

* Bottom field (even scan lines) scan line numbers 2, 4, 6, 8, 10, 12, etc.

* The video frame does not always capture the exact same content that a film frame contains

* Motion does not appear as smooth; diagonal lines are jagged"

This would be true in the case of a film camera and a video camera recording the same scene, but this is not the case here.  A telecine will capture both fields from the same frame.  Jaggies are an artifact of interlaced origination, not interlaced telecine.  You shouldn't get jaggies on either an interlace or 24 PsF transfer.

I know I'm being a bit pedantic, but THX should explain things correctly.

It then goes on to say:

The theatrical version of the film and the individual special edition scenes were all tranferred and put through the DRS process using the above methods to 1920x1080 24PsF video. Because the HD version was similar to film in regards to being 24 frames per second progressive, editing the special edition version together was much easier than dealing with interlaced vdeo masters.

The 24PsF format enables scenes to be added due to the 24-frame-per-second video rate. Prior HD formats were 30-frame based which meant the film images were recorded with a 3:2 sequence in order to fir 24-frame-per-second film on a 30-frame-per-second video format. The 24PsF format allows seamless editing and post production to take place without the 3:2 sequence, implenting this only after scenes are added. The produces a perfect 3:2 sequence integrity which is critical for the MPEG-2 compression forDVD

blah blah...

From my understanding, they're not saying that "Progressive Segmented Frames" means that the film is shot as progressive, rather the video is progressive, just like the film is progressive - that's what they're saying

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Good question, perhaps they feel it's easier to work with. Owen is the expert on the 1080i/p deinterlace question, but my understanding is that quite flawless for 1080i 50/60, the feedback on Sony's 1080p Qualia rear pro seems to indicate this. Check it out on AVSForum..

The easiest way to explain this is to imagine (theoretical) material shot in 1080 50P.  To convert it to 1080 50i you have to drop half the vertical resolution (every alternate line) from each frame.  When the image is static that's OK, becasue the two fields will still combine to produce a full resolution image.  But when the image moves you've only got half the resolution, because the fields don't line up anymore.

So, as you can see, a theoretical conversion of 1080p to 1080i will result in up to a 50% loss of potential resolution.

+

Wrong, PsF means it's recorded as 1080i, i.e. interlace.

My reply.

I think you are incorrect in saying that a 1080/50p recording converted to 'i' is a loss of 50%. If I was to record a 1080/25p tape, I can play that tape back (without any change) as 1080/50i. The resolution is the same, its the 'presentation of the frames that is different. This will result in a difference in the apparent 'flicker' on Plasmas/LCDs. Most CTRs don't even do 'P' mode, only 'i' mode.

However if you take 1080/50i and convert it to 1080/50p there can be a loss in resolution.

PsF means 'Segmented' as opposed to 'Progressive' or 'Interlace'. You are close in that PsF captures the image for both fields at the same time but records them as 2 fields (line 1,3,5 etc then line 2,4,6) like 'i' mode. Progressive captures a frame and then records it as line 1,2,3 etc. Interlace captures 2 fields at different times and records them as 'i' mode, line 1,3,5 etc then line 2,4,6.

This is all from the Sony HDW-F500 manual and the Miranda format standards chart.

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The 24PsF format enables scenes to be added due to the 24-frame-per-second video rate. Prior HD formats were 30-frame based which meant the film images were recorded with a 3:2 sequence in order to fir 24-frame-per-second film on a 30-frame-per-second video format. The 24PsF format allows seamless editing and post production to take place without the 3:2 sequence, implenting this only after scenes are added. The produces a perfect 3:2 sequence integrity which is critical for the MPEG-2 compression forDVD

I think I get what they're on about now.

In effect, what they are saying is that last time they transferred the movie and cut scenes into it, (once it was in the video domain), they stuffed up the 3:2 cadence. As one frame in every 3 consists of two fields from different film frames it's essential that edits take this into account, otherwise it can confuse the deinterlacer and cause jaggies.

Happily for us we don't have to worry about 3:2 because the movie just gets sped up to 25 fps, i.e. 2:2.

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