HDSDI OUT is 420

[Emmanuel Plakiotis]

A couple of days ago at IBC I asked the Japanese tech guy responsible for the EX1/3

[George Kroonder]

For playout yes (4:2:0 8-bit padded to 10-bit); for live feed, it's 4:2:2 10-bit.

This subject is months old. There is this thread; see post #7, #11 en #39.

In that last post Matt Jeppsen from FreshDV recontacted Bob Ott from Sony to address this very issue. Aparently Sony keeps giving out the wrong info at events.

George/

[Harm Millaard]

George,

Today the Sony rep I talked to (might have been the same guy, but with the number of reps there it seems unlikely) confirmed Emmanuel's post. HD-SDI has a spec of 4:2:2 but the signal from an EX3 is nothing more than 4:2:0 due to the circuitry used. This apparently applies to both live feeds and recorded feeds.

He went as far as saying that HD-SDI on the EX3 makes no sense at all from a color space perspective.

[Emmanuel Plakiotis]

A couple of days ago at IBC I asked the Japanese tech guy responsible for the EX1/3 cameras about the LIVE FEED of the HDSDI OUT
He replied, that although the signal is formatted as 422 in reality the quality is 420, because after it is captured from the CMOS, is processed in the 420 colorspace. He then proceeded to explain that in such a small camera a higher bitrate or larger color information would result in overheating.
After I was challenged by other members of the forum that I had misunderstood I went back today. I asked more than ten times the same question in various ways so it will be clear to him and the answer was always the same:
The signal is formatted as 422 but the quality is 420. I asked other Sony people in the booth but every one of them directed me to him as the most knowledgeable person on the EX1/3 series camcorders. Then I went to the person responsible to the XDCAM line and asked the same question about the F355 (the F335 was noticeably absent) . He said the same thing referring for the F355, that although the signal is formatted as 422 the quality is 420. So I asked, if EX1/3 are a similar case and he reaffirmed it.

I know neither of them spoke the best English, but I was so insisting that its not possible that I had misunderstood them.

I guess further clarification from Sony is due.

[Steven Thomas]

No verification needed. It's filling all 10 bits 4:2:2.
This had been veirifed many times here.


When blowing up EX1 4:2:0 images up against the 4:2:2, you can clearly see there's a difference.

A while back, someone even posted an EX1 4:2:0 and the same frame from SDI 4:2:2 here:
http://www.dvinfo.net/conf/sony-xdca...omparison.html

[George Kroonder]

I've updated my post with the references to the earlier discussion.

George/

[Ola Christoffersson]

Originally Posted by Steven Thomas

No verification needed. It's filling all 10 bits 4:2:2.
This had been veirifed many times here.


When blowing up EX1 4:2:0 images up against the 4:2:2, you can clearly see there's a difference.

A while back, someone even posted an EX1 4:2:0 and the same frame from SDI 4:2:2 here:
http://www.dvinfo.net/conf/sony-xdca...omparison.html

Hm... Are you not confusing things a bit now? That comparison is of MPEG 35 Mbit/s versus uncompressed HD-SDI. Wheather the HD-SDI is 8 or 10 bits is not possible to judge from these images.

[Barry J. Anwender]

It would be helpful for and Engineer from Convergent to provide some factual confirmation one way 4:2:2/10-bit or the other 4:2:0/10-bit. Convergent is expending considerable resources to develop a product that is intended to make full us of the signal out of EX1/3 SDI port.

For my part, it's hard to believe that Convergent would be advertising SDI 4:2:2/10-bit potential, charge a good buck for this capability and then deliver something less.

[George Kroonder]

I believe Cineform has looked at the HD SDI out and confirmed all 10 bits contain data (no padding) and it is 4:2:2 color data.

George/

[Steven Thomas]

Yes,
Sorry... I meant to write 10bit 4:2:2.

This was confirmed by Cineform for the EX1.

[Jason Bodnar]

Again I can confirm my live HDSI feed was 10bit 4:2:2 as well. From the EX1.

[David C. Williams]

Here's an FYI for anyone who want's to test this themselves. Record a scene to both SxS and to a HD-SDI capture card on your computer. Take the same frame from both recordings and zoom in to close to pixel level. 4:2:2 will always have two pixels side by side of the same base colour. 4:2:0 will always have four pixels in a square of the same base colour when in progressive mode.

[Ian Firth]

Hi,

sorry for being so much a neophyte, but I have watched the above thread and Emmanual's quote was: <<the answer was always the same: The signal is formatted as 422 but the quality is 420>>, so all the words to go and look that HD-SDI is 4:2:2 do not address the quality, but the format, and that wasn't the claim.

So my question is, when people say "you can see the quality difference" are you sure that what is being looked at is truly a difference at the output or is it a difference produced post output?

Hope this makes sense to you all, because, as I say, I am on the edge of my understanding of the two process chains here.

Cheers, Ian

[David Newman]

Sorry guys, CineForm hasn't tested this. Anyone with an EX1/3 in San Diego, we would be happy to do so. Or capture a live HDSDI feed to an uncompressed (or CineForm) AVI a red object on a blue background in 60i mode and send me the data. This will be straight forward to determine 4:2:2 vs 4:2:0 up sampled. As for 10-bit vs 8-bit, I expect the precision is 8-bit in either case.

[Piotr Wozniacki]

Oops... Is Convergent Design the next major player now to come and admit "they haven't tested this"? Could it be that everybody just hoped on Mr. Martinez words, because they liked them?