Comparing Codecs
 

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.

new forum
 

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.

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.

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.

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...

I'm starting to feel different about XDCAM HD codec. I agree with you 100% on bigger chips. Ever since I started shooting on 2/3" chips I never looked back. Though I do get assignments frequently to shoot promotional clips (not broadcast) of club dancing, boutique make-over’s and fashion clips with the PD170 which I really like.

One question that pops up with the release of the F350 is how they handle over and under-cranking capability. If they have a marker every 6 or 15 frames for the GOP how do they handle over-cranking at 5 fps or time-lapse recording (one frame every 5 minutes etc)?

I'm definitely going to stay positive and open on the XDCAM HD F330 & F350. Actually the only other camera I've been considering for HD production is the Infinity HD camera, because it has 2/3" chips and includes the 2/3" HD Lens in the price. The only thing is that if you want to records using a 4:2:2 color-space you have to use some weird codec called JPG2000 HD @ 110Mb/s. The good new is this camera with lens will come in under $35K! Although the F330 with good HD glass will come in under $25K. If I were going for the F350 I think you get much better value on the Infinity, since you know your going to have to add at least $14K to the $26K of the F350 for your HD glass.

Interesting MPEG article.
 

I did read that article it's very interesting, by any chance have you ever heard of a codec called JPEG 2000? Check out the little blurb below.

JPEG 2000 compression is also frame accurate—making it
ideal for post-production editing or compositing work. It syncs
with audio and metadata better than other schemes. It also
provides 4:2:2, 10 bit image quality, which combined with its
other features make it ideal for HD. This is one reason why
acceptance is growing for this format. Recently, the Digital
Cinema Initiatives Committee selected JPEG 2000 as the
standard for digital motion picture content and delivery.

end blurb.

If Avid and FCP support JPEG2000 then Infinity will be a real success.

you can bet J2K is going to be VERY successful. It's a brilliant technology that blows most anything else in its class away. I'm certain we'll soon see support for this in most every application, because there isn't a lot to implementing it.

Wow that sounds like a good recommendation. Well I guess I'll be buying a new J2K enabled camera at NAB 2006 event this year. I wonder why more pro-camcorder manufacturers aren't using or implementing this codec.

J2K was late to the party due in great part to hardware, but that has changed in the last year as TI and Philips have started shipping the necessary chips.
J2k is totally scaleable, and kudos to Grass Valley for implementing it. It's expensive at an entry level of 35k, but since everyone is so into superlatives, it blows the HDV and P2 formats out of the water, and more importantly, it's scaleability can carry over to the editing platform. Quality of image is wonderful, but you don't need a proxy or compressed media format *if* the NLE can use the scaling properly. You can have an image on your timeline that is scanned at say...5% and while it looks acceptable for editing you can then dial it up to 95% for rendering, and your color hasn't shifted, nada. you're just editing on a lesser grade frame of the image because of the way the thumbnail is created.
I'm very impressed with the J2K technology, and have been since participating in a panel for J2K at NIST several years ago. I hope Sony, Adobe, Avid, etc jump all over this, and I suspect they'll have to. Canopus for certain, will be there soon, given that Grass Valley has purchased Canopus.

The most descriptive article I've come across on the Infinity is here - http://www.nzcrews.tv/infinity_on_horizon/ . The whole article may be worth looking at, but as a brief extract:

In addition to many codecs, it provides a choice of two media - Compact Flash and Rev Pro. A small TV station may do a range of work, from local news to occasional features which may have an archival value, or possible wider saleability. Being able to shoot news DV25 onto Compact Flash may be most appropriate from a speed/ease of editing point of view (backing up to Rev Pro as you go?), whilst the same camera may be better used HD JPEG 2000 onto Rev Pro for feature work.

Like P2, and unlike XDCAM, Compact Flash doesn't need a dedicated (and expensive) drive to interface with an NLE - many computers come standard with a reader slot. And whilst CF capacities are comparable to P2 cards, Compact Flash prices are much lower.

In principle and on paper the Infinity would seem to have much to commend it, but other than it being 2/3", little has so far been released about the camera front end. If that turns out to be at least comparable to the opposition, the recording flexibility of the Infinity could make it very, very attractive indeed. Early days, but worth keeping an eye on.

What seems odd to me is that there isn't more talk about doing something in between HDV and other more expensive options. The HVX200 is a move in the right direction but doesn't work for many of us because of the high price of P2 memory, so how about something like that using a restrained data rate ~50 Mbps recording to more affordable stock media cards? And forget the fancy $35K cameras: give me a good 1/2" sensor with a fixed lens for under $15K and I'd be happy. I'm puzzled why we're not seeing anything along those lines yet...

Done... finally! Thanks for the suggestion, Kevin!

If anyone wants to test MJpeg2000, you can download 30day eval versions from Lead Technologies at
http://www.leadcodecs.com/

I think the individual mjpeg2000 codec goes for 9.95 (directshow).

Don't know how good they are, but they have a good reputation in the still image world, at least among Delphi developers.

On the subject of Codecs, where does Avid's DNxHD fit in. They claim it offers the best size/quality ratio and it is free. Is anyone out there working on hardware that will allow camcorders to natively capture in this format?

Just wanted to add a few things about XDCAM that haven't been bought up already.
The decks are selling at around $10K, now that's not small change but still cheaper than a JH3. However the decks provide connectivity via Gbit ethernet which means just about any PC or Mac made today comes ready to connect, no need for expensive SDI cards and RAID disks, this is a huge saving for a TV station, they can use cheap IT ethernet switches instead of expensive SDI bits and pieces.
Now I've only seen this demoed on Sony's Xpri system but it's pretty impressive stuff. XDCAM disks include mpeg 4 proxies, you only need ingest these tiny files to start editing, once you're finished the system only captures what full res footage it needs, this must be way faster than the P2 workflow and remember you can keep all the original footage on the affordable disks in case you realise later you need something not already ingested. In the demo I watched at NAB last year within less than 5 minutes of the disk going into the drive editing commenced, you don't even need to get all the proxies into the system before you can start, this has to be a killer for ENG.
I might also mention that the disks come with a basic viewing and editing package on the disk, how neat is that. You can copy that and the mpeg-4 proxies onto a single DVD for the client to view while you retain the masters. I had one given to me last year to look at, very impressive and totally simple to use, being able to view and log 40 minutes of footage from a DVD without needing anything other than a basic PC has got to be another big selling point.
I suspect the argument against the format based on the use of higher bitrate HDV is going to come to nothing. The bigger CCDs are going to deliver a lower noise image to the encoder and noise has to be HDVs worst enemy, no wonder the HVX200 doesn't record in HDV.
What's going to be interesting is Sony have just released an upmarket range of HDV decks, they look like they're aimed at the broadcast market as they'll record HDV onto D5 shell DV tapes for 4 hour recording times. If HDV becomes a content delivery standard for broadcast then I think the noise issue is going to need to get more attention

ARe you refering to the SD XDCAM 4:2:2 50Mbit/s
 

You mention seeing a lot of this XDCAM equipment demoed last year. Are your refering to the older XDCAM SD gear or are you refering to the new not yet available XDCAM HD gear. The reason I ask is there is a significant difference between the two formats. The SD allowed frame accurate editing and was providing a (4:2:2) colorspace. The new XDCAM HD video I believe use the long GOP to record the video material and doesn't allow frame accurate edits. Therefore all your comments about the proxies will be different and the editing will be different. I'm not so sure your comparisons are actually accurate to the new HD version of the camera.

XDCAM HD is 4:2:0

Dang, haven't we gotten past that myth yet? Yes, XDCAM HD uses a GOP-structured MPEG2 video stream, but that doesn't mean you can't do frame-accurate editing.

By the way, does anyone happen to know what the GOP structure is for XDCAM HD?

Long GOP is what the XDCAM HD uses from what I understand.