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-   -   Real 1080 24p @ 4:2:2??? (https://www.dvinfo.net/forum/sony-hvr-v1-hdr-fx7/80520-real-1080-24p-4-2-2-a.html)

Sam Jankis November 27th, 2006 11:57 PM

Real 1080 24p @ 4:2:2???
 
I tried searching the forums for info about color sampling for the V1U.

In Douglas Spotted Eagle's first look at the V1U, he writes:

"The camera processes 1920x1080 in the 4:2:2 color sample scheme before processing for tape storage at 4:2:0, 1440x1080 for HDV."

After checking out the HVR-DR60, I got to thinking... would this camera and recording deck allow me to shoot real 1080 24p with 4:2:2 colorspace?

If so, then I'll be saying goodbye to my HVX200 (even with the upcoming CinePorter).

Nate Weaver November 28th, 2006 12:25 AM

No. Firewire out to the DR60 is an HDV stream, making it 4:2:0 also.

Harm Millaard November 28th, 2006 03:06 AM

You would need HD-SDI to maintain 4:2:2.
An alternative could be the G1, which has HD-SDI.

Kristin Stewart November 28th, 2006 03:21 AM

No Harm : HDMI supports the 4:2:2 colorspace. You can capture this signal with the new Blackmagic Intensity card (actually only working with towers, not laptop), see previous post "HDMI ouout to laptop"

Harm Millaard November 28th, 2006 04:27 AM

Kristin,

Thanks for the info and I stand corrected.
I should have said, you need either HDMI or HD-SDI.

Still, the HVR-DR60 only accepts firewire, so that is not an option to get 4:2:2 colorspace.

Kristin Stewart November 28th, 2006 07:10 AM

Yes Harm,

I'm dreaming of an easy direct-to-disk way to record this HDMI signal... like a lot of people I presume !

Harm Millaard November 28th, 2006 07:23 AM

The problem is going to be the disk. When using either a 1.8" or a 2.5" HD in an external device, the transfer speed will be the bottleneck, due to the relatively low RPM's. When going to 3.5" plus large caches, possibly in a raid0, you gain the speed but lose the portability, not to mention battery life.

Peter Ferling November 28th, 2006 09:41 AM

Portability is going to be an issue for both HDMI and HD-SDI. The holy grail being a solid state device that's light enough to carry.

Currently all bets (mine at least) are using a Canon G1, going SDI to a shuttle or shoe-box size PC with a dual chip board that will accept a full sized card and two disk array. Using a cineform intermediate encoder, it's a good compromise between HDV and fully uncompressed. Still 4:2:2 at 10bit.

Even if a labtop was doable, currently the weaker processors/heat dissapation, room for disk array, etc. would disqualify.

Finally, if you're going for 4:2:2 uncompressed, then why the HDMI route? HD-SDI is the proper tool for this, as you'll benefit from timecode, genlock, etc.

If you just want occasional 4:2:2 and good quality for studio work, etc. that's fine. For mobile or run and gun, it's you on a dolly or cart being pushed by a grip with a cable wrangler following close behind. Still, your weakest link would be the camera and with HDMI, your limited to a short cable.

I don't plan to shoot SDI all the time, in fact, most of stuff will be in HDV. When I do shoot uncompressed, however, SDI is the way to go.

Thomas Smet November 28th, 2006 10:09 AM

Again everybody assumes you can only capture uncompressed through SDI or HDMI which is not true at all.

On the mac side you have DVCPRO HD or photojpeg which can easily fit on a single laptop drive and will have 4:2:2 color and much higher quality then HDV.

On the PC side with the new Intensity card you have the new Blackmagic jpeg based AVI codec that will also fit on a single drive.

There are other codecs as well such as Cineform or the Avid DNx codecs.

For the Matrox Axio platform they use a I frame based mpeg-2 codec that can use as low as 100 mbits or the same datarate as DVCPRO HD.

If and when we get a laptop HDMI card there will be plenty of options for capturing not uncompressed but high quality HD video that could be near uncompressed quality.

Finally SDI and HDMI are not the only options for high quality HD video. You can use component as well with a HD component capture card. It isn't a perfect digital signal but it is high quality and 4:2:2.

Peter Ferling November 28th, 2006 10:51 AM

Correct about the analogue component. However, the difference between an all digital workflow is the issue here. SDI allows more features and the longer cable runs needed.

Kristin Stewart November 28th, 2006 11:28 AM

Thomas, I didn't say you can only capture uncompressed with HDMI. It would be interesting to do a comparison between these codecs and an uncompressed source. I just tried the new jpeg one from Blackmagic and the picture seemed a little soft, probably because my source wasn't uncompressed.

If I remember correctly, the Avid DNxHD isn't a codec for capture, but for post (2 pass). So capture uncompressed and convert to the Avid DNxHD for storage ?

An SDI workflow seems more expensive than the one we could build with HDMI, no ?

Gene Latimer November 28th, 2006 11:50 AM

Quote:

Originally Posted by Peter Ferling
if you're going for 4:2:2 uncompressed, then why the HDMI route? HD-SDI is the proper tool for this, as you'll benefit from timecode...

Is timecode not embedded in HDMI? (If not, how does one reconnect it with the output of an Intensity card?)

Peter Ferling November 28th, 2006 01:12 PM

HDMI 1.3 was designed to be full rez playback pipe for consumer viewing only on high rez monitors. Therefore no timecode is needed nor provided.

Let me also add that it's not a replacement for/or to be considered as the new firewire. It's just raw video and audio.

Thomas Smet November 28th, 2006 02:42 PM

Quote:

Originally Posted by Peter Ferling
Correct about the analogue component. However, the difference between an all digital workflow is the issue here. SDI allows more features and the longer cable runs needed.

I thought the question was a way to have 4:2:2 and not so much a digital workflow. While analog is not perfect it is another option for 4:2:2 HD video. I do agree if you have a V1 then it may be better to use HDMI since it is digital.

Thomas Smet November 28th, 2006 02:49 PM

Quote:

Originally Posted by Kristin Stewart
Thomas, I didn't say you can only capture uncompressed with HDMI. It would be interesting to do a comparison between these codecs and an uncompressed source. I just tried the new jpeg one from Blackmagic and the picture seemed a little soft, probably because my source wasn't uncompressed.

If I remember correctly, the Avid DNxHD isn't a codec for capture, but for post (2 pass). So capture uncompressed and convert to the Avid DNxHD for storage ?

An SDI workflow seems more expensive than the one we could build with HDMI, no ?

I saw a lot of people talking about needing a raid-0 with the laptops so I just wanted to remind everybody else that it isn't so.

As for the Blackmagic codec, well it isn't perfect but look at the level of quality you do get for a HD stream that runs off of a single hard drive. The quality beats the pants off of HDV with only a slightly larger bandwidth need. I think the level of tradeoff of quality vs. bandwidth with the Blackmagic codec is much better then that of HDV.


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