Canon's new 50Mbps MPEG-2 Full HD (4:2:2) codec

[David Clark]

A 1/2 inch CCD block, with the new codec, with out the problems of CMOS? Yessssssss. I think that would really up the ante Canon!

For me, the dream would be a shoulder mount version of that. Hey maybe it would look like an EX3!

[Chris Hurd]

I doubt very seriously that it will be one-half inch. For numerous reasons that
I have stressed many times previously, it will most likely be one-third inch.

[Steve Phillipps]

I tend to think you're right Chris, only seems strange as if they are meeting broadcast specs with the 50 mb/s codec that they don't meet it with the chips too. For sure if they did a lot of people would buy it for broadcast use - rather than an EX1/3 with Nanoflash - but maybe that's not a big enough market for them to be concerned with.
Steve

[Chris Hurd]

Broadcast specs can vary from one channel to the next. While the BBC, Discovery HD and PBS have certain stringent technical barriers to entry, others do not. Take for example the Lifetime Channel series "Lovespring International," acquired entirely on the 1/3rd-inch Canon XL H1 camera, or Discovery's "Deadliest Catch" which used numerous 1/3rd-inch Sony Z1U camcorders. For better or for worse, content from small-chip camcorders goes to air all the time these days.

[Monday Isa]

I have a question pertaining to 4:2:2 acquisition. As a event videographer what added benefits does this have over 4:2:0? I know it helps in vastly in the broadcast arena and also for chroma keying. As a event videographer what added benefits would this color space bring? Thanks!

[Robert M Wright]

Originally Posted by Michael Murie

But AVCHD only supports 4:2:0, so I'm guessing they had to use something else if they wanted to offer 4:2:2.

32Mbps is outside the AVCHD spec, and so is 4:2:2. That's irrelevant. Both are well within the AVC spec.

[Robert M Wright]

Originally Posted by Alister Chapman

So are Canon supposed to wait another two or three years for computers to get to the point where they can edit 3 or 4 streams of native AVCHD in realtime or release a camera now which should be perfectly capable of producing top rate HD pictures? It's highly debateable as to whether AVCHD is better than Mpeg2 at 40Mb/s plus bitrates anyway. AVCHD is optimised for low bandwidth, sub 15Mb/s use and this is where it excels. Most of those optimisations do nothing other than increase CPU load when it's used at high bit rates.
What happens in 3 years time, sensors will have moved on, codecs will change etc. There is a market that exists now for easy to edit, high quality HD cameras, Canon can't ignore that if they wish to stay in the pro market.

Edius Neo 2.5 is already offering to edit up to 3 or 4 streams of AVCHD at once.

Apparently editing AVC actually is manageable for professional purposes, at least somehow! Otherwise, a lot of Panasonic (and soon to be Sony) camera owners are in deep doo-doo. (I know it's a well kept secret, but Cineform still works pretty good - even better than it did on the computers we had back when HDV was new!)

Indeed, the lower the bitrate, the greater the image quality difference between AVC and MPEG-2 compression. That doesn't mean there is no point in going above 24Mbps with AVC, or that AVC is somehow worse than MPEG-2 at higher bitrates! I read something recently, that the gist of it boiled down to Sony concluding it was practical to get about the same image quality with AVC at 30-35Mbps as with MPEG-2 at 50Mbps, which is a pretty reasonable assessment to make. This isn't science fiction, nor very debatable really.

[Steve Phillipps]

Originally Posted by Robert M Wright

32Mbps is outside the AVCHD spec, and so is 4:2:2. That's irrelevant. Both are well within the AVC spec.

What spec is 422 outside of? It's OK for the EBU.

Chris, of course there is variability in what standards are acceptable, with the lower grade channels having lower grade standards (in general). But for those aiming high in broadcast to have a full EBU/BBC/Discovery approved camera in a sensible price bracket has long been on a lot of folks' wishlist. The EX cameras almost get there as does the Panny 301, but without add-ons there is still no sub $10k or even sub £10k that ticks all the boxes - but maybe there soon will be (with Scarlet if not the Canon!) And even with Scarlet, unless they have a non-RAW workflow I think a lot of broadcasters would still be pretty scared of it. MPEG (and HDCam, DVCPro, AVC) is familiar to the editors and therefore very desirable.
Steve

[Robert M Wright]

Originally Posted by Alister Chapman

What happens in 3 years time, sensors will have moved on, codecs will change etc. There is a market that exists now for easy to edit, high quality HD cameras, Canon can't ignore that if they wish to stay in the pro market.

3 years from now (and quite awhile after-wards most likely) the HD codecs used for recording, in prosumer camcorders, from the major manufactures, will almost assuredly be essentially the same as they are right now - variations of DVCPRO, MPEG-2 and AVC. It's more than a bit of a stretch to imply that if Canon had gone with AVC in this new cam, they would somehow have effectively conceded their place in the pro market - not hardly.

[Robert M Wright]

Originally Posted by Steve Phillipps

What spec is 422 outside of?

AVCHD is a format that Sony and Panasonic came up with, that includes video encoding that is a pretty narrow subset of the full H.264/AVC/MPEG-4 Part 10 spec. 4:2:2 color steps outside the bounds of AVCHD, but is certainly not invalid for H.264/AVC/MPEG-4 Part 10 video encoding. The EBU had nothing to do with setting the H.264/AVC/MPEG-4 Part 10 or AVCHD specs (that I am aware of).

[Lou Bruno]

Originally Posted by Steve Phillipps

There's pictures on the Canon article which shows the form factor - not going to keep shoulder shooters happy - and also has size that indicates 1/3" chips and CCDs. Maybe the pictures were a red herring and they've done a complete redesign. After all the article predicts AVCHD codec!

Originally Posted by Chris Hurd

I'm the author of that article. In it I have mentioned the strong possibility that yet
another new model waits in the wings; a shoulder mount version of the mock-up which is the subject of the article.

Sources tell me there will be ,in fact, a shoulder version. Again, as reported neither HDV or AVCHD.

[David Heath]

Originally Posted by Robert M Wright

I'm a bit disappointed Canon chose to go with MPEG-2 compression in their new cam. That choice seems a little short-sighted (to me), when you consider that this cam (and siblings) is likely to constitute Canon's pro camcorder offering for the next half decade.

It won't be long until AVC is just as easy to edit (give it a year or two) as MPEG-2 is today, and editing AVC is quite reasonably manageable currently.

With AVC encoding at 32Mbps, Canon could have offered very close to the same image quality (or better), with some very nice side benefits.

At 32Mbps, recording to low cost media reliably is much easier than at 50Mbps. Even just decent class-6 SDHC is adequate for recording at 32Mbps,.....

Most engineering decisions involve compromises, and you have to weigh up pros and cons.

On the side of 50Mbs is that it is a relatively tried and tested solution. It's already well supported by NLEs, etc. Coders are relatively easy to make, and relatively cheap therefore. It meets oft-quoted minimum recommended spec requirements, no arguments. Yet at the same time, it's low enough to be easily recorded onto fairly basic consumer media - class 6 SDHC of a decent brand should be OK, the EX/SDHC limitation has more to do with the adaptor and interface than the media itself.

So why move to AVC-HD? (Or a form of long-GOP AVC that is outside the AVC-HD spec to enable 4:2:2.) The ONLY advantage I can think of is a lower bitrate, so more minutes can be recorded per GB. But is it worth it?

Against that, moving outside AVC-HD specs begs the question of what NLE support will be like, certainly for the first year or two. Even if supported, performance is likely to be down compared to working with MPEG2. Coders will have to be complex to code in real time and get anything like equivalence at the 32Mbs you mention - and that likely means much more expensive and power hungry. Or they could be simpler and less powerful and get equivalence at (say) 40Mbs maybe - but is the 20% saving then really worth it?

An analogy may be the differences between engineering decisions for a basic family car and a high performance racing car. For the latter, it may be necessary (if expensive) to use lightweight alloys to reduce weight to get the performance, for the former, it's unlikely the gains would justify the cost. In this respect, the complexity of AVC-HD may be well worthwhile when coding for transmission (and bitrate= big money), but much less so if all it does is save a few GB of fairly cheap memory.

As far as the longer future goes, then my expectation would be that memory will come down further in price, and bitrate reduction for acquisition become even less of an issue. Yes, computing power will likely increase, but it seems far more sensible to use this to enable wavelet codecs such as JPEG2000.

In the meantime, MPEG2 seems a good compromise for this level of acquisition recording, H264 for transmission and squeezing content on to such as Blu-Ray. (In the latter case, it's much easier - the coding doesn't need to be real time.)

What the chip size will be remains to be seen. My feeling is that it SHOULD be 1/2" to really give Canon the edge, when they could claim to meet all the desired broadcast recommendations. If they do go for 1/3", my vote would remain with the EX - you can always add a nanoFlash to a 1/2" camera, you can't add 1/2" chips to a camera with a 422 codec!!

The announcement also must be a wake up call for Sony. I've made no secret that I like a lot about the PMW350, but think it should have the 50Mbs codec. Now that Canon have included that in a far, far cheaper camera, what do you think it's going to be like for a Sony salesman? How many times is he going to have to put up with hearing "but why doesn't it have the 50Mbs codec?" at a tradeshow?

[Perrone Ford]

Originally Posted by David Heath

Now that Canon have included that in a far, far cheaper camera, what do you think it's going to be like for a Sony salesman? How many times is he going to have to put up with hearing "but why doesn't it have the 50Mbs codec?" at a tradeshow?

Probably as many times as the Panasonic salesman hearing "why does it cost $3200/hr to shoot on a $5k camera?"

[Andrew Kimery]

Originally Posted by Monday Isa

I have a question pertaining to 4:2:2 acquisition. As a event videographer what added benefits does this have over 4:2:0? I know it helps in vastly in the broadcast arena and also for chroma keying. As a event videographer what added benefits would this color space bring? Thanks!

Colors would contain less noise and the image could be processed more in post before 'falling apart.' The same thing that provides a smoother edge for chroma keying would also supply a smoothing looking fall off of, let's say, a color light on a stage or a presenter standing in front of a big power point presentation.


-Andrew

[Robert M Wright]

4:2:2 acquisition offers event videographers the same benefits it offers broadcasters - leeway in post production. Both event videographers and broadcasters deliver their final product encoded with 4:2:0 color. Actually, ENG for broadcast is event videography.