The Megabits chart

EDV

EDV

Well-known member
Okay, I know it's not called "the Megabits chart", but give me a break, I couldn't think of anything else



Does anyone know where I can find a more presentable version of this chart?
One I could print out perhaps?
 
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XDCAM-HD is not 50 megabits, it's 35.

And why do you want that chart? It's relevant for storage space, but it's really not relevant as per quality. A megabit of one type is not equivalent to a megabit of another type.
 
I am doing a presentation on the HPX172 at a professional association meeting, a very technically savvy audience. They seem to have a bias towards bigger shoulder mount interchangeable lense cameras. The chart shows how the DVCPRO HD stacks up against other industry standard formats ( I will also mention color space and compression ) I know there's a lot more to it than this chart, but it's a good reference point. Needless to say, I will try to highlight the HPX's strengths at the meet.


P.S. Thanks for the correction Barry, someone posted 50 Mbits/s in one of the other forums and it seemed like a reliable source, but I guess not!
 
There is a new "XDCAM-MPEG422" format that's 50 megabits. But the existing "XDCAM-HD" and "XDCAM-EX" are 35 megabits.

Something else that's missing from your chart is color sampling. All the codecs you listed there are 4:2:0 or 4:1:1, except for:
DVCPRO-HD, DVCPRO50, and Digital Betacam are 4:2:2
HDCAM is 3:1:1

If you're trying to sell the viability of the DVCPRO-HD codec, you could always just point to Discovery HD's standards, where they accept DVCPRO-HD for unlimited acquisition, editing, and mastering. (they do not, however, accept the HPX170 for unlimited acquisition, due to the 1/3" chipset)

Or you could point to NBC, who just made a major shift to P2 and bought lots and lots of P2 cameras for their owned & operated station group; they bought the HPX300 for shoulder cameras, and HPX170s for handheld cameras.

There are certainly ways to make a presentation that can be convincing. But like Mikko said, are you trying to convince them to go along with what you've already decided? Or are you trying to give them the facts and let them come to their own conclusion?
 
I guess any camera owner would be biased towards his own particular brand of choice, but my intention is to present the HPX as a pro cam capable of hanging with the big boys. I will also mention what I think it's missing.... a better lens and more tweakable image controls, compatibility with larger pro batteries... but for these features I guess I will need to upgrade to the HPX370. The NBC P2 shift is definetely worth mentioning, as is the Iditarod series on Discovery (the one made with 21 HVX200s). Does anyone know whether this was the Iditarod 2008 or was it the Iditarod 2009?

Besides the camera features, I plan to touch briefly on the P2 Workflow.
I've got 3 P2 Cards a 64Gb A Series, a 64Gb E Series and the 16Gb R series that came with the camera. Does anyone know what the "R" series is about? How is it different from the other series?
 
I think that doc was 2008, but I'm pretty sure 2009 was shot with a lot of HPX170s too.

R=older, A=slightly faster, E=fastest/cheapest but with limited rewrite cycles.
 
While we're in the mood for Q & A... what is this DSP I hear about? I know it means Digital Signal Processing, but what does it do exactly?

From the creative cow forum:

"That 4:2:2 color space and Panasonic's superior DSP are the very reasons their color looks consistently superior compared to Sony => with 4:2:0 three quarters of the chrominance values have been deleted."

Thread link:

DVCPRO HD vs HDCAM HD

http://forums.creativecow.net/thread/126/857922
 
Well, I revised the original Megabits chart and have come up with a better version.



I took all of the information from the internet, but most of it should be correct. As I said earlier, it's only a reference chart. And yes, we spell colour differently in Australia. :)
 
DSP is number crunching - the analysis and conversion of the raw digital data to more useful information, such as from CCD chips, cellhone signals, deep space signals, and so on. The quality of the design of the software algorithms determines how well the raw data is finally presented/used. These algorithms are generally highly proprietary and some are better than others, hence the differences you see in different manufacturers and even different cameras from the same manufacturer.

Someone (much more qualified than I) apparently evaluates these algorithms and passes judgment.
 
Chart Corrections: XDCam isn't 422, unless it's the new 50mb version, and DVCPRO 100mbit/sec totape?
 
DVCPRO HD when recorded on tape.
I imagine when recorded to P2 card it would be much less. Probably close to 50 Mbit/s.
On the subject of 4:4:4 color space... the HPX3000 has it.... anyone know what format it uses to render 4:4:4 ?
 
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EDV said:
On the subject of 4:4:4 color space... the HPX3000 has it.... anyone know what format it uses to render 4:4:4 ?
Click to expand...

For P2 cards when recording internally, it records AVC-Intra 100 which is 4:2:2

You need 2 HD-SDI connections out with an external capture device or card to record the 4:4:4 signal . 1 port will only carry 4:2:2
 
Might be a bit picky, but your "colour space" on the revised chart actually refers to chroma subsampling.

"color space" refers to Y'CbCr vs. RGB vs. CMYK etc.. or models of describing color.

For example, the uncompressed output when using HPX3700 or HDCAM-SR is RGB colorspace, with no subsampling (4:4:4) , but when the HPX3700 is using P2 cards, it records to AVC-Intra which is Y'CbCr colorspace, with 4:2:2 chroma subsampling (The chroma components , U, V, have 1/2 the bandwith of the luma component Y').
 
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Thanks PDR. I'll update the chart.
One last thing I need to mention on my presentation is to do with P2 cards. Are they hot-swappable?
One of my colleagues assures me they're not:

"The one thing you must NEVER do with these cards is hot swap.
Always turn camera off when changing cards. I was warned by a camera
repair tech. It states you can hot swap in the manual .....don't!
He's seen loss of data, damaged cards etc."

He's more experienced than me, so I don't know....
 
They are designed for hot swap, that's the whole point of having more than one slot. As long as the matching light on the slot isn't blinking, you can safely pull out the card anytime.
 
EDV said:
DVCPRO HD when recorded on tape.
I imagine when recorded to P2 card it would be much less. Probably close to 50 Mbit/s.
Click to expand...
It's the exact same format, whether recorded to P2 or to tape. It's 100mb/sec. The only time it isn't, is if you're using the 720pN mode, in which case it only uses as much bandwidth as you use frames (so, 30pN = 50 megabits, 24pN = 40 megabits, etc).


On the subject of 4:4:4 color space... the HPX3000 has it.... anyone know what format it uses to render 4:4:4 ?
Click to expand...
As said before, that's not color space, that's color sampling. The HPX3000 can't record 4:4:4, it can only output it over dual-link HD-SDI. It records 4:2:2.

Also, your color sampling section needs some changes. First, the Sony XDCAM-HD and XDCAM-EX formats aren't 4:2:2, they're 4:2:0. Second, if you're in australia, DV and DVCAM are 4:2:0, not 4:1:1. DVCPRO is still 4:1:1.
 
EDV said:
"The one thing you must NEVER do with these cards is hot swap.
Always turn camera off when changing cards. I was warned by a camera
repair tech. It states you can hot swap in the manual .....don't!
He's seen loss of data, damaged cards etc."
Click to expand...
Yeah, that's nonsense when it comes to P2. It's specifically designed to be hot-swappable. I've done it probably two million times (maybe a slight exaggeration) with never a problem.

SDHC cards, yes you can cause a problem or even lose a card if you eject it while it's being read from or written to. But P2 cards have circuitry in them specifically to prevent that from ever happening.
 
Hey guys! The presentation went well... thanks for all your contributions. The only let down was that the DVD player they had wasn't working properly, so I couldn't show them anything. I found Barry's books and DVDs really helped me prepare for this presentation. Understanding all the features and functions made me appreciate my HPX even more! One minor correction I should point out: the European and Australian 50 Hz HPX does not have a NORMAL option (as stated in the Book and DVDs) under Aspect Conv, if you want 4:3 you have to choose SIDE CROP (sounds awful, I know).


I'll post an updated version of the chart tomorrow.
 
As promised...



some settings are only applicable to the 50 Hz version (DV & DVCAM color sampling)
 
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