XDCAM HD - new forum?

[Kevin Shaw]

Originally Posted by Keith Wakeham

XDCAM is tapeless but I suspect its going to be fairly robust and reliable, yet it still presents the same workflow issues when reusing the discs.

That's assuming you reuse the discs, but at $30 or so per hour of recording time you could afford to store them for several weeks before making the decision to reuse one. Compare that to P2 memory at $200 per minute of recording or DTE drives at ~$5-10 per minute, and that's a whole different ballgame in terms of designing your workflow. Sounds like we could use a resolution-neutral forum just to discuss tapeless workflow options.

[Douglas Call]

The XDCAM HD captures 4:2:0 colorspace at 35Mb/s and the HVX200 captures 4:2:2 colorspace at 100Mb/s. Which one do you think will have the highest quality video? The difference between XDCAM 1/2" chip and the HVX 200 1/3" chip probably won't make up the quality difference of the sub $6k HVX200. I don't know but I'm guessing.

[Mike Marriage]

Originally Posted by Douglas Call

The XDCAM HD captures 4:2:0 colorspace at 35Mb/s and the HVX200 captures 4:2:2 colorspace at 100Mb/s. Which one do you think will have the highest quality video? The difference between XDCAM 1/2" chip and the HVX 200 1/3" chip probably won't make up the quality difference of the sub $6k HVX200. I don't know but I'm guessing.

The Sony uses more efficient compression though. I would think the codecs would be evenly matched but the Sony camera head should be superior. The Sony also has the option of using high quality glass.

[Chris Hurd]

Originally Posted by Kevin Shaw

Sounds like we could use a resolution-neutral forum just to discuss tapeless workflow options.

Maybe that's the suggestion I was looking for... a category called Tapeless HD Acquisition, covering P2, XDCAM and whatever else comes down the pike.

And I must agree about not re-using discs... why would anyone want to re-use a disc, unless it's just scratch material that you're re-recording over.

[Keith Wakeham]

Sorry, forgetting cost per unit time of XDCAM discs. I'm out in uncompressed thinking all the time so I slip up a little when I look at other things like this.

I think Tapeless HD Acquisition would be a good category to put several groups in. 2 Camera's so far and possibly move the direct to disk recording solutions to it. Editcam and Infinity could eventually be added to.

[Kevin Shaw]

Originally Posted by Douglas Call

The XDCAM HD captures 4:2:0 colorspace at 35Mb/s and the HVX200 captures 4:2:2 colorspace at 100Mb/s. Which one do you think will have the highest quality video? The difference between XDCAM 1/2" chip and the HVX 200 1/3" chip probably won't make up the quality difference of the sub $6k HVX200. I don't know but I'm guessing.

It will be interesting to see this comparison made when both cameras are shipping. I'm guessing that the size of the XDCAM sensors will offer some distinct advantages over any of the small-chip cameras, but this may not matter to those who like the look the HVX200 delivers. Also note that the HVX200 in 720p/24 mode records barely more data per second than XDCAM at maximum quality, so there again it will be interesting to these two compared.

[Douglas Call]

I stream video on a regular basis since 1999 and I can tell you categorically that if you watch a video clip at 112Kb/s (ISDN) rate it sort of looks ok if you used Cleaner XL or some other good utility. Now if you take 100Mb/s / 30Mb/s = 2.86 times the capture rate, multiply 112 * 2.86 = 320Kb/s its a huge difference also I think your underestimating frame accurate 4:2:2 colorspace. Think of it this way would you rather have a car with 30HP or 100HP? If you like economy you want 30HP if you want ??? you get 100HP car.

That being said I have used both the Sony VX2100 and PD170 and think they are excellent cameras. I believe the new XDCAM HD is also an excellent camera, I think the 1/2" heads will give it better depth of field and allow it to use 1/2" Fujinon HD glass.

You really need to understand that a approx. 3 times higher capture rate on the HVX200 is a significant factor, but it looks like its being underated or ignored. I can't wait to see the live tests of these cameras once they get in the hands of the pros on real client shoots!

[Mike Marriage]

Originally Posted by Douglas Call

Think of it this way would you rather have a car with 30HP or 100HP? If you like economy you want 30HP if you want ??? you get 100HP car.

I don't think that is the same though. The Sony's MPEG2 compression is far more efficient that DVCPROHD. It is more like saying "do you want a car that uses 100ml of fuel per mile or 30ml/km." Both cars may produce the same level of performance, you would have to test them to see which was best or you.

The actual data rate isn't important (well, lower bitrates are easier to store), it is how good the codec looks.

[Douglas Spotted Eagle]

Originally Posted by Mike Marriage

I don't think that is the same though. The Sony's MPEG2 compression is far more efficient that DVCPROHD. It is more like saying "do you want a car that uses 100ml of fuel per mile or 30ml/km." Both cars may produce the same level of performance, you would have to test them to see which was best or you.

The actual data rate isn't important (well, lower bitrates are easier to store), it is how good the codec looks.

Exactly. If you had a 30HP motor that can deliver 100HP performance, you'd rather have that, wouldn't you?
At the end of the day, there will always be the folks that look at math, and that makes decisions for them. Then there are those that look at the picture, and for them, the perception of the picture regardless of what its math properties are is more important. Codecs and compression schemes regardless of what they are, improve every day, while math is just...."math."

[David Heath]

Originally Posted by Mike Marriage

I don't think that is the same though. The Sony's MPEG2 compression is far more efficient that DVCPROHD. It is more like saying "do you want a car that uses 100ml of fuel per mile or 30ml/km." Both cars may produce the same level of performance, ............

I'll agree Mike. A more appropiate analogy may be two engines each producing 100hp, one a diesel and the other a gas turbine, same power output, but very different power/weight ratios. Neither is 'better' than the other, but one may be far more appropiate for a given vehicle than the other, for many reasons other than power output. The efficiency of the turbine is likely to come at a price, whether it's worth it or not has to be decided on a case by case basis. The "cost" in codec terms is more likely to translate to matters such as editing ease than image quality, assuming a high enough bitrate. What can't be concluded is that because a diesel engine weighs 1000kg it will be more powerful than a gas turbine "because that only weighs 300kg".

Quality wise I'd expect these two codecs to perform very comparably, and any differences to probably be masked by the differences due to 1/2" v 1/3" chips etc. But the camera with the higher quality chips is more expensive.

[Douglas Call]

May I ask what article you used to base your opinions about the efficiency of the new XDCAM HD 35Mb/s mpeg-2 codec? Is there an article that has specifically tested this new codec? If so did it test it against other mpeg codecs or many different codecs include DVCPRO etc?

I'm not trying to be argumentative I'm actually trying to see how you got the factual information about the new codec? If it clearly has proven to be almost as efficient as the DVCPRO HD etc codecs Than I would reconsider the Sony XDCAM HD.

Although the now brings up the Long GOP issue. Apparently you only get to register precisely the current image every 15 frames in Long GOP. The DVCPRO HD codec allows each frame to stand entirely by itself without requiring addtional cues from marker frame further down stream.

[Jacques Star]

Well...then you're trying to categorize us shooters when you talk money spent on gear.

I, for one, DO own a Sony Z1U HDV camera, and spent about $4,500 for it.

On the other hand, I spent $24,000 on a D35WS head, with DVCam and BetacamSP dockable backends, plus 2 lenses. Sounds like a lot of money, but I actually got a really great deal...

I'm sure there are other shooters on here who are in the same spending bracket.

I would have no complaints buying an XDCAM, but quite frankly, i'd rather buy a 2/3" IMX/DVCAM XDCAM shooting in SD with a 2/3" HD lens than a 1/2" XDCAM HD camera with a 1/2" HD lens that's not quite as good.

24p MPEG IMX shot in 50 mb/sec through an HD lens onto a 2/3" sensor will look good upconverted to 720p. Have you seen upconverts of SDX900 footage? It looks very nice.

[Bob Grant]

Douglas,
almost anything will be more efficient than the DVCProHD codec, best way to think of DVCProHD is as just 4 DV codecs running in parrallel. Yes, as it doesn't use intraframe compression it is going to be easier to edit but then again the issues raised by having to handle intraframe compression in post were solved long ago by the use of intermediate codecs.
What is a real challenge for intraframe compression schemes is noise. As DCPRoHD doesn't use intraframe compression it is going to handle noise very well, probably a good thing too on the HVX100 but it's almost inevitable that your footage is going to go through intraframe compression, be it DVB broadcast or mpeg-2 for DVD.
Just take a look at the Dixie Chicks DVD shot on the DVX100, I bought that DVD to try to convince the boss to switch from PD150s to DVX100s but instead it showed why we shouldn't, just checkout the noise in the blacks.
And please don't anyone tell me it looks more 'filmic', film doesn't have noise that gets frozen when the encoder runs out of bandwidth.
The other thing with noise is it only gets worse in post, that's why I'm a big fan of larger CCDs, if nothing else the lower noise levels means you can push the footage around more in post. Just last week I did some post work on typical DV footage from a 1/3" 3 CCD camera. It had already been CC'd and the noise in the interior shots was just woeful despite a fair amount of light being used.

[David Heath]

Originally Posted by Douglas Call

May I ask what article you used to base your opinions about the efficiency of the new XDCAM HD 35Mb/s mpeg-2 codec? Is there an article that has specifically tested this new codec?

My own comments were based not on one specific article, nor the XDCAM 35Mb implementation specifically, rather on what's been published about MPEG2 at varying datarates in general. My understanding is that a lot depends on the coder itself (newer implementations obviously tending to be generally better than older), and the picture content. Codec A may outperform B on scene X, but be inferior on scene Y - hence 'comparable' quality tends to be talked of rather than 'equivalent'.

All that said, you may be interested in reading this paper from IBC 18 months ago - http://www.broadcastpapers.com/ibc20...DDEL-print.htm . In particular, note the figures for MPEG2 bitrates given in Table 1 - 12-20Mbs for transmission to home, 25-40Mbs for broadcast contribution circuits, and 30-50Mbs for live e-cinema. Going on those figures, 35Mbs for HD is considered within the industry to be high for a broadcast contribution circuit, and even within the range for live e-cinema! (In other words, pretty good. :) ) There are so many variables that defining it as better or worse than such as DVCPRO HD is virtually impossible, and likely to vary scene by scene anyway.

But I would expect it to be comparable, and far more so than the 35v100Mbs figures would initially lead to believe. And the chip size differences of the cameras to be more significant quality wise than the codec differences.

[Kevin Shaw]

Originally Posted by Douglas Call

You really need to understand that a approx. 3 times higher capture rate on the HVX200 is a significant factor, but it looks like its being underated or ignored. I can't wait to see the live tests of these cameras once they get in the hands of the pros on real client shoots!

Like I said before, note that the maximum recording bit rate for XDCAM HD is similar to the bit rate for the mode many people will use on the HVX200, which is 720p/24 at 40 Mbps. At that point the larger, higher resolution sensor and (hopefully) better glass on the XDCAM should offer image characteristics you can't get from any of the smaller cameras, but we won't know that until we see sample footage side-by-side of the same scenes. Should be an interesting year...