HDV Pixels

If you play a 1080i60 HDV clip in Quicktime, the INFO says 1920:1080. If you open an HDV timeline, it says 1440:1080. The setup says 1440:1080 (16:9) but 1440:1080 works out to be 4:3.

The HDV timeline exports stills at 1440:1080. HDV appears to the untrained eye as using non-square pixels.

I thought all HiDef formats used square pixels. Did I miss a class somewhere?

??????

Koz

Koz-

My understanding is that HDV works like anamorphic SD. In fact you ARE using non-square pixels. I guess you have to do something to squeeze all that data down to fit on those ity-bity tapes! :-)

I believe that HDCam is also subsampled at 1440 H pixels, but I am prepared to duck the slings and arrows of those with real understanding of these formats.

-V

I did get the exported frames out the door by doing it from QuickTime7-Pro and not FCP. I don't think there is any way to do it in FCP.

QuickTime will export the "viewing" format which is 1920:1080. There are way too many gotchas with this. If you chose to view the work at "half size" on your screen (to get it all *on* your screen if for no other good reason), that's the size of the export stills.

Surprise.....

I'm buying a new loose-leaf binder for the additional spells I'm learning.

Koz

Ok to help your understanding I'll give a brief overview of HD formats for you:

-----------------------------
Analog HD format
-----------------------------
SMPTE 260M 1035i
1920x1080 16:9 aspect ratio @ 16:9 30/29.97 or 60/59.94


-----------------------------
ATSC HD Standards
-----------------------------

ATSC 720p
1280x720 16:9 aspect ratio @ 23.976p, 24p, 29.97p, 30p, 59.94p, 60p fps

ATSC 1080
1920x1080 16:9 aspect ratio @ 25 (50i), 29.97 (59.94i), 30 (60i) 23.976p, 24p, 29.97p, 30p



-----------------------------
Recording Formats
-----------------------------

HDV1
1280x720p, 4:2:0 color sampling, MPEG-2 compressed @ 19Mbps, Audio @ 384 Kbps MPEG-1 Layer 2 stereo (2 Channel Audio)

-----------------------------

HDV2
1440x1080i, 4:2:0 color sampling, MPEG-2 compressed @ 25 Mbps, Audio @ 384 Kbps MPEG-1 Layer 2 stereo (2 Channel Audio)

-----------------------------

Panasonic D7-HD aka DV100 aka DVCpro100 aka DVCproHD
1280x1080 or 960x720, 4:2:2 color sampling, compressed 6.7:1 @ 100Mbps, Supports 10-bit input and output per channel. Also supports 8 channels of audio.

-----------------------------

Sony HDCAM
1440x1080, 17:6:6 (3:1:1) color sampling, Discrete Cosine Transform (DCT) compressed 4.4:1 in 8-bit @ 440Mbps. Supports 10-bit input/output & 4 channels of audio.

-----------------------------

Panasonic D5-HD
Uses the D3 tape shell. 250Mbps, Compressed 4:1 in 8-bit mode, 5:1 in 10-bit mode & supports 4 channels of audio. Also supports 1035i.

-----------------------------

Sony HDCAM SR
1920x1080, 4:4:4 color sampling, MPEG-4 Studio Profile Compression @ 880Mbps with upto 12 Audio Channels Supported

-----------------------------


Regards


Ben King




PS: I haven't added the fps supported for each format as I don't have time at the moment but may edit in later.

I hope this is all correct and no random numberblindness or typo-faeries have caused me to get anything wrong.





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I knew pieces of the HDCAM SR. There's nothing like going to internal tone and watching all 12 audio meters wake up.

Koz

Ben-

GREAT summer, thanks. It is going to wind up in my reference file.

I do have a question.

QUOTE:

-----------------------------
Analog HD format
-----------------------------
SMPTE 260M 1035i
1920x1080 16:9 aspect ratio @ 16:9 30/29.97 or 60/59.94

UNQUOTE

I have had access to older HD material for a couple of projects. It always seems to be missing a hunk of video at the top of the frame. I was under the impression that what was missing was the difference between the 1035 lines of the analog recording and the 1080 digital form it came to me in. Does 260M speciify 1920x1080 or 1920x1035?

-Vance

Grr I need a spell checker here.

I meant Great summery. I have no idea how your summer was.

-V

Yeah as far as I'm aware 1035i is still a 1920x1080 raster - so it should fill the same area...

Unfortunately I can only go from a guy who worked on it 18 years ago (yes you read correctly 18 years ago the BBC and other peeps were working on HD!).

Please bear in mind that I was told second hand about 1035i and in a pub conversation so my info might be a little wrong but I think it should still be displayed 16:9 and if converting to 1080 then you need to expand the image to fit.

Plus there are are top line field issues especially when converting so you don't get a jerky image due to reversed fields:

I think (don't quote me) that 1080 and all digital HD is "Upper Field First" i.e.: Field 1 always contains the top active line, aka Odd Field.

In "Lower Field First" (Field 2 dominance aka Even Field), the top active line will be in the second field transferred.

1035i HD & 525-line NTSC are both lower field first (Field 2 dominance or Even Field).

PAL DV is lower field first but Standard PAL is upper field first.



Please could someone else confirm this as I'm no longer in touch with the engineer and it will bug me until I find out for definite! I wish I hadn't had that extra pint of Guinness when he was telling me about it!


Regards

Ben





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Oh and my summer was filled with work and not sleeping well due to being English and not capable of dealing with hot humid weather!

Thanks for asking though





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Ben-

Thanks, and sorry to hear about the summer. Sounds like you got some of your information the same way I did. I have always thought of this as "cocktail education". As a result I am pretty clear on the overview, but fuzzy on the details. One or two drinks to frame the question, the details thatcome after the bartender is putting up the free ones are a bit fuzzy!

-Vance

Free!!! Damn you must be a charming guy - I have to pay for my drinks...





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