The option of V1 720p
 

Last fall when writing my first story (for the HDV@Work Newsletter) on Sony's 3ClearVid technology I wrote the following:

"With a different recording format, I believe the CMOS/EIP engine is capable of outputting 1080p50 or 1080p60 to an encoder. In fact, I suspect the EIP can not only downscale 1920 to 1440, it can also downscale to 1280. And, with 50p or 60p video available in the EIP buffer—1080 can be downscaled to 720. Thereby, offering Sony the option of super-sampled, 720p."

Today from a good friend, I learned my theory seems to be correct.

When Sony's HDMI chip senses that an HDMI interface wants 720p video -- it signals the V1 to enter "720p" mode.

In this mode:

1) The camera captures 960x1080p60 into the EIP where it is interpolated to 1920x1080p60. The EIP output is then downscaled to 1280x720p60. This 4:2:2 uncompressed signal is output via HDMI.

There are several open questions:

I'm assuming 720p60 is obtained when the V1 is in 60i mode. Which means -- here we go again -- 60i is deinterlaced to 60p.

Is the downscale done from the 1920x1080 signal or from the 1440x1080 signal? (I suspect by the HDMI chip does the downscale from 1440x1080.)

Is the 4:2:2 output from the 4:2:2 signal or from the 4:2:0 signal?

It appears 1080i60/24p is not converted to JVC's ProHD 720p24 because JVC uses Repeat Flags and not 2-3 pulldown.


2) If you are playing a 1080i60 HDV tape -- the recording is downscaled to 1280x720p60. The 4:2:0 MPEG-2 is decoded and the now 4:2:2 uncompressed signal is output via HDMI.
(HDMI is 4:2:2 after chroma upsampling from 4:2:0.)


3) If you play a 720p30 or 720p60 tape -- the V1 transport will play the tape and decode the 4:2:0 signal and output the now 4:2:2 720p uncompressed signal via HDMI.

>>> It will not work with JVC 720p24 ProHD tapes.

>>> I'm not sure if 720p30 tape playback is output as 30Hz, as 60Hz, or as 59.95Hz. (The HD1/HD10 records at 30Hz not 29.97Hz.)

If you own an HD-Connect MI, all three become 720p over HD-SDI:

http://www.convergent-design.com/CD_...DConnectMI.htm


>>> This will work with Region 50 as well. Output will be 720p50.

One hopes BMD will soon offer the ability to set its Intensity HDMI chip to "only request" 720p.

Of course, the key is a near-lossless codec like that from CineForm.

Hopefully someone owns an HDConnect MI and can confirm this with their V1.

<<< 7 Days and Counting >>>

Thanks, Steve, this is indeed good news and hopefully support will be forthcoming with the Intensity card.
Michael

We own two HD Connect MIs. Did mention this quite some time ago.

Yes the camera's HDMI chip rescales based on the MI's format request.

There is however a bug in the camera which the latest MI firmware fixes, the first 4 lines of vision contains embedded data of some unkown purpose. Latest firware detects that it's a Sony camera (all Sony cameras with HDMI outputs have this bug) and blanks the first 4 lines.

Only tested MI output to SD SDI into a good monitor, looks stunning. Will try recordring to DigiBeta in the field once we have battery pack for MI.

Why the interest in 720p50? IMHO, not much to get excited about in R50, just not a big enough step up from 576p50.

The Intensity card comes from BMD not AJA. That and the Cineform capture does look pretty interesting.

Bob, 720p is a much better format than 1080p as a lot of problems with 1080 are solved by converting back to 720p. If I could remember an article on how much better 720p is I'd post it, but!!!
Michael.

Well if you can't see a difference between interlace PAL and progressive 720p -- then I guess you would have no interest. Many -- if not most folks can -- so there is an interest.

As an owner of an Intensity card this is interesting news, if possible. Steve, do you think this would also be possible while outputting through a Sony 25U deck, or just through the V1?

576p50 isn't interlaced.

Down here the standards are for SD is 576i, for HD 576p, 720p, 1080i.

Confusing isn't it. Not that hard to see how the broadcasters like this, they can transmit their SD PsF content as 576p and meet their mandated HD broadcast requirements. Aside from that loophole the bulk are going for 1080i.

I can understand the advantage of 720p in the current climate but the serious money does seem to be heading for 1080p. Currently I agree the chances of it ending up displayed correctly when broadcast as 1080i are pretty close to zilch but all that is subject to change.

Question for this thread
 

We have a V1 and little A1. We have been seriously debating doing our new children's production using the Intensity card with the Cineform codec and saving our output from the V1 as uncompressed 1920x1080p60 (4:2:2) for editing.

REASONS?: It would seem that if we can retain our production in that higher format, downscaling would then be easy for current needs, and done with very high quality. PLUS we would be "future-proofing" our long-range productions for whatever comes down the road in the days to come. Plus possibly using it with Brazil's to-come-yet digital TV system...

QUESTION: what is right or wrong with this plan? I have been debating this for a number of weeks and now our production date is drawing close. I need some input as to possible pro's and con's. Any suggestions?

I'd buy your new book Steve, but that still a week away.... :(

Thanks

We also have a 480p60 standard -- except its not been used. But, it may be become very popular when analog is forced to go away. I agree that camcorders will go 1080p50 and 1080p60 as soon as BD burners become cheap/available. Hitachi is going to have one in about 18 months.

Look for AVCHD at true 1080p24 at 24mbps later this year. Looks like that's the next format not to be supported by our NLE's. :)

Actually, AVCHD at 24mbps should be able to handle the p50/p60 output from the EIP. The question is when will the AVC encoders match the quality of MPEG-2 encoders now being used. And, how quick will Sony kill-off HDV after the AVC encoders become ready.

My general understanding is that the more advanced codecs are designed to deliver good quality at lower bandwidths, giving them more bandwidth doesn't yield much in the way of quality improvment. I think AVCHD will not be a replacement for HDV apart from at the lower end of the market.

Probably at the next level up is where we're going to see interesting things happening, developments like the Wafian recorder would seem to offer very good quality at more affordable prices. The same people are able to do the same magic with the Intensity card. Perhaps advances in silicon will one day mean that could all be packaged into a camera. The big thing holding it all back seems to power consumption.

There's a strong feeling here that AVCHD is designed to replace HDV for two reasons:

1) The 1920x1080p24 at 24Mbps spec. already exists. I expect product in late 2007. To MiniDV tape or to red laser DVD. (The consumer version is limited to 15Mbps.)

2) To support 1920x1080p50 and 1920x1080p60 -- which is 2X more data -- the codec needs to be more than 2X more "efficient" which is what a good AVC encoder will do. *1920x1080 is Full HD.)

There has to be something to sell us just when we get all our HDV bought. :)

PS: "Probably at the next level up is where we're going to see interesting things happening, developments like the Wafian recorder would seem to offer very good quality at more affordable prices. The same people are able to do the same magic with the Intensity card." Unfortunately, this is not where Japan is going. They will have their own path that is AVC-based. Nothing not MPEG-2 or MPEG-4/AVC will ever be part of their plans. Red and Wafian are "homebrew" products that are noise to Sony and Panasonic. Even JVC has lost the race and been bought by Texas Pacific Investments for only $688 million.

There is no tape based acquisition. AVCHD will be acquired on DVD, memory or HDDs.

AVCHD does NOT support 1080p only 1080i and 720p.

Even if camera were announced at NAB that will still require NLE manufacturers to provide support and if the HDV rollout is a barometer then HDV would still be the savvy purchase. Apple and Avid still have not signed up to support AVCHD so the big two will drag their feet.

Other than that your post was spot on.

TT

I can see nothing wrong with the idea at all.
First though you'd need to consider what you'll use to backup your data, HDDs aren't the best for long term data storage. Any IT solution would work though.
Secondly keep in mind that it seems you'll need to blank the first 4 lines of vision due to Sony putting some oddball bits of data in there. This can be a bit of pain and can slip past you if you're not careful. Most 16:9 TVs will blank those lines but if it's broadcast in letterboxed SD those lines are very much visible. The question that remains though is should you also blank the bottom 4 lines as well to keep things even. Don't know the answer to that one.

Someone correct me if I'm wrong, but I thought the V1 goes through a resolution converter before output to HDMI and component. So that would mean that although the camera scans 1920 x 1080p through horizontal pixel shift, the best achievable resolution at output after conversion is 1440 x 1080i, probably upsampled to 1920 x 1080i 60, not 1080p 60.

[QUOTE=Tony Tremble;647868AVCHD does NOT support 1080p only 1080i and 720p.

Other than that your post was spot on.

TT[/QUOTE]

Actually according to Japanese reports that I have in print -- there is a 1920x1080p24 spec at 24Mbps. (Of course, 24Mbps also supports 1920x1080i.)

The reason for 24p is obvious: it's no big deal to encode AND it eliminates the 2-3 pulldown mess. It works just like Canon's 24F.

You are looking at the current Consumer version of the spec.

Pixel-shift isn't being used. V and H interpolation of all three colors is.

The HDMI chip gets only 1440 from the EIP which is then down-scaled to 1280. I'll bet the HDMI chip simply up-scales each field from 540 to 720. Presto -- 1440x1080i to 1280x720p. The FIELD rate becomes the FRAME rate.

I think there is a huge difference between 576p and 720p. While the vertical resolution may not be that much higher the horizontal gets jumped from 720 up to 1280 which is a lot of extra horizontal detail. Sadly widescreen SD is still limited to 720 pixels (or 768 pixels for full PAL specs). This means widescreen SD ends up having to deal with the same anamorphic softened pixels as 1440 HD is compared to true 1920 HD.

The reason why a lot of 720p shot material looks pretty close to 720x576p material is because most 720p broadcasts are shot with DVCPROHD which only uses 960x720 pixels which is only slightly higher then 720x576p. A high quality camera shooting a nice detailed 1280x720 image will have a lot more horizontal detail (almost double) then 576p could ever have.

I guess I missed something here. Didn't Sony just put out a fix on that oddball data prob on the first 4 scan lines? Don't the newer cam's have that already blanked now? Anybody have info on that?

Plus, is the HDMi port outputting 1920x1080i then? The Cineform codec handles the progressive conversion, so what's the catch, or is there one?

As to long-term storage, that has always been a moving target anyway, so we'll just HDD the productions for now, then when the larger capacity disks hit the market in a bit, we'll dup our backups onto that format as well to get us down the road. Hitachi's new 1TB drives will hold plenty, and it looks like they are very reasonably priced.

Good question!

If it is 1920x1080:

Is it up-scaling 1440x1080 to 1920x1080?

Or, is it getting a direct feed from the EIP?

I suspect the first.

But, if it gets 1920x1080, then the 720p would be a direct down-scale.

I now believe that the V1U's 1440 x 1080i HDMI output can be upsampled to 1920 x 1080i (most likely scenario) or downsampled to 1280 x 720p depending on the capabilities of the monitor or TV used. I'm unfamiliar with Black Magic's intensity card, but I imagine you can set to capture either interlace or progressive. If anyone has newer information, I would be most interested to know. Anyway, it is important to note that V1 outputs a 4:2:2 high definition signal via HDMI or component, so it should bid well for keying and/or advance color correction.

It would seem that if the V1 can truly output what it appears it's outputting to HDMI, then our plan of utilizing the Intensity card for ingest and conversion to the Cineform codec for post is a winner. Even though we'll have other input to deal with (from the tiny A1), our main cam for this is still the V1, so the final production should look quite nice.

Maybe we'll get another V1 so we can use the sync capability for two cams...hmmm...

BTW, we really like the V1's layout and handling. This little cam looks like a true winner and seems to bode very well for those of us trying to do much with relatively little (non-profit children's production).

Now, if we can just figure out how to do all this when flying our Merlin, we'll be almost there. The crane and dolly are easy, but the Merlin is SO sensitive to anything, it'll take something new to make it usable under this scheme of things.