HDCAM Question

[Dino]

the 4:2:2 and it’s variants are an awkward bit of nomenclature. They are defined by a set of rules in which any particular instance can only reference itself. They can not necessarily serve as a means of comparison between different items. I would also say that 4:4:4 is almost a misdirect as what it conventionally means is RGB. Why can’t we just say RGB?

What you need to know:
HDCam and DVCProHD are both 8 bit sub-raster, filtered formats with high compression. They have certainly proven valid and acceptable in the professional world. They are however far from ideal.

HD-D5 and HDCam SR are both 10 bit full raster with milder compression. HDCam SR is the newer and better of the two. It has quickly become the delivery standard in many parts of the industry.

What you output to depends on what is available to you and what your client wants. If you have no client, HDCam is the most universal. that is, you should have little trouble getting at an HDCam deck most anywhere in the world.

Your high quality master could just be a ProRes file which you can always output to whatever is needed once the need arrives. Just keep more than one copy, please.

[Seawild]

Thanks Dino,

So when I playback a 10 bit ProRes 422 (HQ) and record to an 8 bit 3:1:1 HDCAM… How much, if anything, am I loosing..

And is there any truth to HDCAM playing back at 4:2:2?

I’m just curious.

thx,
Chris

[Dino]

In a Component Digital High Definition, Y, Cr, Cb 1080 full raster image
Y has 1920 samples per line, Cr and Cb have 960 samples each.

In HDCam
Y has 1440 samples per line, Cr and Cb have 480 samples each.

In DVCProHD
Y has 1280 samples per line, Cr and Cb have 640 samples each.

In HDV
Y has 1440 samples per line, Cr and Cb have 720 samples per every other line.
(each color channel exists only on every other horizontal line)

[Chris Rogers] “HDCAM playing back at 4:2:2”
Any format that stores a sub sample raster has to resample a full raster image for transmission on a fixed standard such as HD-SDI or HDMI. All that Sony means by this is that regardless of what the deck actually records, the signal delivered at the output conforms to the established standard (in this case, SMPTE 292M).

Why 4:2:2 can fail to describe quality:

In hypothetical A
Y has 256 samples per line, Cr and Cb have 128 samples each.
this is defined as 4:2:2. I’d hate to the fool trying to sell that.

In hypothetical B
Y has 3840 samples per line, Cr and Cb have 1280 samples each.
this is defined as 3:1:1. That would be lovely.

[Mark Raudonis]

Chris,

All tech specs aside, are you willing to pay, or does your budget support HDCAMsr decks? If not, this discussion is moot. (There’s a HUGE difference in price between the two formats)

mark

[Seawild]

So if I understand you correctly..

I’m going to lose around 25% of my Luma info and about half of my color info… right? ouch.

[Seawild]

Hi Mark,

It’s not moot.. it’s moooooo : ) (academic)

Chris