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Old September 23rd, 2005, 02:41 AM   #1
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Are there any cams that store truly progressive frames as opposed to segmented?

I was wondering, are there any HD cameras that actually store a truly complete frame on tape or are frames always divided into fields when stored(like with frame based DV material or 24PsF)?

I'm talking solely about frame-based cameras, where I know there's no practical difference between a stored segmented frame and a stored full frame in practice since the field pairs can just be woven into a full resolution frame. However, am correct in saying that there are no video cameras that actually store an entire frame/picture on tape?

Do direct-to-disk recording systems store progressive in the same way as tape, i.e. also segmented?

720p HDTV MPEG2 does contain true progressive frames, right? (as do the many PC formats like Quicktime/MPEG4 and WMV)

Thanks,

Roy

Last edited by Roy Bemelmans; September 23rd, 2005 at 06:54 AM.
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Old September 23rd, 2005, 03:19 AM   #2
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Quote:
Originally Posted by Roy Bemelmans
I was wondering, are there any HD cameras that actually store a truly complete frame on tape or are frames always divided into fields when stored(like with frame based DV material or 24PsF)?
DVCPRO-HD and HDV 720p are the only frame-based HD compression systems I can think of that are in common use; among top-end formats I believe HD-D5 also stores full frames; I would guess HDCAM-SR does, but don't know for sure...

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However, am correct in saying that there are no video cameras that actually store an entire frame/picture on tape?
No, because at the very least, DVCPRO-HD and 720p HDV both store frames as frames.

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Do direct-to-disk recording systems store progressive in the same way as tape, i.e. also segmented?
Firewire-based disk recorders record whatever they're fed by firewire, so if you're talking about an interlaced tape-based system (like 1080i HDV, DV, etc) being recorded on a disk, then yes it'd be interlaced/segmented.
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Old September 23rd, 2005, 06:51 AM   #3
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Thanks for the reply, Barry. I was actually talking about frame-based/progressive cameras only (not the difference between progressive and interlaced cameras).
Most frame-based/progressive cameras divide the complete frame that they capture into fields for storage and compatibility. Even the CineAltas (HDCAM) do this (24PsF).

I was wondering whether there are any HD cameras that actually store a truly complete progressive frame on tape/disk? (admittedly, a rather theoretical question)

Roy
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Old September 23rd, 2005, 08:23 AM   #4
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the HD100 and the Varicam are both definitely pure progressive.
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Old September 23rd, 2005, 02:02 PM   #5
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Right -- the VariCam and the HD100 both store progressive frames as progressive frames, and the HVX will as well.

I guess in my initial answer I answered which formats were capable of it, rather than spelling out specifically which cameras use it. But the idea was, any progressive-scan camera using DVCPRO-HD (such as the VariCam or the HVX) or any progressive-scan camera using HDV 720p (which includes the JVC HD1, HD10, and HD100) will all store its progressive frames as progressive.

HDCAM is an interlaced codec, so yes, the CineAlta writes 24pSF. DVCPRO-HD/720p and HDV/720p are both pure progressive codecs. So any cameras employing those formats will inherently store pure progressive frames.
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Old September 23rd, 2005, 04:06 PM   #6
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It would also be sufficient to state that the DV25 format stores truly progressive frames at 24pA, 25p (no pulldown) and 30p. While the middle (junk) frame in 24pA is likely written as two fields, any full progressive frames in the stream will be analyzed and stored as such.

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Old September 24th, 2005, 07:11 AM   #7
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Thanks, Barry. I misread your first post, of course.

Ok. So your NLE will actually handle these formats in a pure progressive manner? What if you were to export that material to mpeg2 for DVD or 1080i HDTV broadcast? Will the MPEG2 encoder interlace the video?

BTW, 720p HDTV MPEG2 also contains true progressive frames (as opposed to MPEG2 for DVD), right? (as do the many PC formats like Quicktime/MPEG4 and WMV if I'm not mistaking?).

If you were to export a HDV/720p24 NLE project to MPEG2/720p60 for HDTV broadcast, the encoder would just create a 720p60 file that repeats full progressive frames in a 2-3 pattern, right?

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Originally Posted by Steven White
It would also be sufficient to state that the DV25 format stores truly progressive frames at 24pA, 25p (no pulldown) and 30p. While the middle (junk) frame in 24pA is likely written as two fields, any full progressive frames in the stream will be analyzed and stored as such.
How does DV25 differ from DV in this respect? Is it a proprietary format?

Thanks,

Roy
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Old September 24th, 2005, 11:55 AM   #8
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Originally Posted by Roy Bemelmans
Ok. So your NLE will actually handle these formats in a pure progressive manner?
Yes.
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What if you were to export that material to mpeg2 for DVD or 1080i HDTV broadcast? Will the MPEG2 encoder interlace the video?
If you go for a 1080i broadcast, then yes. If you go for a 1080p or 720p broadcast, then no it won't interlace it. Remember, five of the six ATSC high-def broadcast standards are progressive; only 1080/60i is interlaced.

As for DVD, if you're shooting 24p you can render as a pure 24p progressive DVD. If it's played back on a progressive-scan DVD player to a progressive-scan television, it'll never be interlaced -- and it looks absolutely fantastic. If it gets played back on an interlaced TV, the DVD player will take care of interlacing the video.

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BTW, 720p HDTV MPEG2 also contains true progressive frames (as opposed to MPEG2 for DVD), right? (as do the many PC formats like Quicktime/MPEG4 and WMV if I'm not mistaking?).
720p is always pure progressive, there's nothing about it that's ever interlaced. And DVDs can be genuine progressive at 24p, or interlaced at 60i, your choice.

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If you were to export a HDV/720p24 NLE project to MPEG2/720p60 for HDTV broadcast, the encoder would just create a 720p60 file that repeats full progressive frames in a 2-3 pattern, right?
That is correct. However, 720/24p is a legitimate ATSC broadcast standard, so the broadcaster could choose to broadcast that file as-is rather than converting it to 720/60p...

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How does DV25 differ from DV in this respect? Is it a proprietary format?
No, just another name for the same thing. DV25 = miniDV = DVCAM = DVCPRO25 (as far as bitstream). DV50 = DVCPRO50 = Digital-S. DV100 = DVCPRO-HD. Just shorthand for the other formats. (well, in the case of DV it's actually "longhand", but you get the meaning...) ;)
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Old September 24th, 2005, 02:05 PM   #9
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Thanks Barry.

So are there any pure progressive 1080p codecs/cams?
DVCPRO-HD only seems to support 720p and 1080i. A camera like the Panasonic HVX200 seems to record 24p in 1080i recording (segmented frames) and the Varicam only supports 720p..

Quote:
Originally Posted by Barry Green
720/24p is a legitimate ATSC broadcast standard, so the broadcaster could choose to broadcast that file as-is rather than converting it to 720/60p...
Do current HDTVs handle 720p24? If so, how?

Last edited by Roy Bemelmans; September 24th, 2005 at 05:04 PM.
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Old September 24th, 2005, 05:23 PM   #10
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So are there any pure progressive 1080p codecs/cams?
DVCPRO-HD only seems to support 720p and 1080i. A camera like the Panasonic HVX200 seems to record 24p in 1080i recording (segmented frames) and the Varicam only supports 720p..
Well, depends what you mean by "pure progressive". DVCPRO-HD will store 1080/24p as pure progressive frames, with one "padding" frame thrown in. The codec supports either progressive or interlaced, and in 1080/24p it stores four frames in a group of five: four pure progressive frames, followed by one "split" frame to round out the sequence.

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Do current HDTVs handle 720p24? If so, how?
Any ATSC-compatible tuner is required to handle all 18 ATSC signals. And 720/24P, 720/30P, 1080/24P, and 1080/30P are all valid ATSC transmission signals. The only ones we ever hear about are 1080/60i and 720/60p, but the others are ensconced in the standard.
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Old September 25th, 2005, 12:36 PM   #11
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Is there any good overview on the web on how different codecs (DVCPRO-HD, HDV, DV, etc.) store video?
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