capture uncompressed HD at DVinfo.net

Trung Dau · January 11th, 2007, 02:57 AM

I'm doing the research of capturing uncompressed HD via HDV camera. The component analog on JVC HD100 and the HD-SDI output on JVC Hd250 only live uncompressed output. So my question is:
Can we only capture while live shooting? CAN'T WE playback the HDV tape and capture it to uncompression hd720/60 4:2:2 ?

Rikard Holmstrom · January 11th, 2007, 05:47 AM

That´s right. if you want to capture a uncompressed stream you have to capture it live, while shooting.
everything on tape will be compressed HDV.

Tim Dashwood · January 11th, 2007, 09:28 AM

Quote:

Originally Posted by Trung Dau

CAN'T WE playback the HDV tape and capture it to uncompression hd720/60 4:2:2 ?

You can do this, but the effects of 4:2:0 and Mpeg2 will already be present when you playback from tape.

Trung Dau · January 11th, 2007, 09:29 AM

Quote:

Originally Posted by Rikard Holmstrom

That´s right. if you want to capture a uncompressed stream you have to capture it live, while shooting.
everything on tape will be compressed HDV.

While the camera playing back, is there any signal out to via the component analogue?

INTENSIVE from blackmagic can capture uncompressed footage via HDMI from the HDV camera. So the HDV camera can playback HDv tape and output uncompressed via the HDMI port, SO my question is why the component analogue can't do that?

Bill Ravens · January 11th, 2007, 09:45 AM

if the signal is coming from the playback(tape) it has been compressed by mpeg to write it to the tape. the camera will decompress it to play back out the component ports, but, you've already suffered the unrecoverable losses of the initial compression to tape. that's unrecoverable.

Eirikur Ingi Bodvarsson · January 11th, 2007, 10:53 AM

Quote:

Originally Posted by Trung Dau

I'm doing the research of capturing uncompressed HD via HDV camera. The component analog on JVC HD100 and the HD-SDI output on JVC Hd250 only live uncompressed output. So my question is:
Can we only capture while live shooting? CAN'T WE playback the HDV tape and capture it to uncompression hd720/60 4:2:2 ?

No, that is not possible, for when the camcorder has recorded on to the tape, the file has been compressed to a Mpeg2-file "4:2:0" You can use the component analog output on the camcorder to capture to analog-HD decklink video-card as a uncompressed hd 4:2:2 but you will not gain any quality by doing so. ( Some like to capture using the analog way so they don't have to work with the HDV format)

The best way is to find or make a device that you can use to record straid from the camcorder "LIVE". A device that can handle uncompressed signal, like a computer, with a BIG harddrive, (prossible Raid) actually a BIG everyting. And a recording software that will support LIVE 60P HD recording.

I am thinking about setting up a system like that my self in the near future.

Sorry about my spelling I come from a land far far away.

Mark Silva · January 11th, 2007, 11:23 AM

Quote:

Originally Posted by Trung Dau

INTENSIVE from blackmagic can capture uncompressed footage via HDMI from the HDV camera. So the HDV camera can playback HDv tape and output uncompressed via the HDMI port, SO my question is why the component analogue can't do that?

Its already been compressed. so no.

although a tech did confirm the HDMI outputs capture live BEFORE
the HDV compressor, so the sony camera is just like the JVC in
that it can output uncompressed live.

Once its on tape though its compressed.

Trung Dau · January 11th, 2007, 07:08 PM

Quote:

Originally Posted by Mark Silva

Its already been compressed. so no.

although a tech did confirm the HDMI outputs capture live BEFORE
the HDV compressor, so the sony camera is just like the JVC in
that it can output uncompressed live.

Once its on tape though its compressed.

IS Convergent Design the solution for capturing uncompressed from HDV tape via fire wire? The HD_SDI output is uncompressed HD format and has the color sample is 4:2:2 . You can have a look at it's specification on this link page 30.
I don't know if it does get back the sample color losses which was compressed in to HDV mini Dv tape.
SAme question as MIranda product http://www.miranda.com/product.php?i=336

Tim Dashwood · January 11th, 2007, 07:28 PM

Quote:

Originally Posted by Trung Dau

...
I don't know if it does get back the sample color losses which was compressed in to HDV mini Dv tape.

You can never get the 4:2:2 colour info back once it has been thrown away with 4:2:0. It can be "smoothed" by some NLE plug-ins.

I have the HDConnect LE and it does work well for converting HDV from firewire to HD-SDI.

Eirikur Ingi Bodvarsson · January 11th, 2007, 07:56 PM

Quote:

Originally Posted by Trung Dau

IS Convergent Design the solution for capturing uncompressed from HDV tape via fire wire? The HD_SDI output is uncompressed HD format and has the color sample is 4:2:2 . You can have a look at it's specification on this link page 30.
I don't know if it does get back the sample color losses which was compressed in to HDV mini Dv tape.
SAme question as MIranda product http://www.miranda.com/product.php?i=336

I do not think so, you my get a good tranfer of your shots. But I don't think you will gain any visual quality becouse of the color sample 4:2:0 Your are missing (the "2") and if the color sample (info) is not recorded, than you can't get it back. So the Miranda product is making up for the missing the "2" in the color sample.

Trung Dau · January 12th, 2007, 04:11 AM

sorry i forget to post the link.
http://www.convergent-design.com/hdm...CSI_manual.pdf
on page 30 u see the color sample is 4:2:2

So what the purpose does Convergent Design and Miranda convert to uncompressed HD or SD for?
So we can edit native HDV and export to any format we want, or u print the result to HDV tape and convert to uncompressed Hd by Convergent Design or Miranda.

Bob Grant · January 12th, 2007, 05:34 AM

Those boxes are targeted at broadcasters who need to route HD-SDI and who only have a HDCAM workflow. We sold several to one network who only use HDCAM-SR, one hour of tape costs around $800 for those VCRs.
They are well aware that they gain nothing converting to HD SDI, it's purely a workflow issue, plus the HDV footage gets intercut with the HDCAM footage.

If you want to capture live from a HDV camera there's a number of ways to do this, Convergent Design have a new box that'll convert HDMI to HD SDI and there's a card from BlackMagic (Intensity) that'll do much the same for you. Bear in mind that you're going to need a very fast disk array to keep up and HDMI cannot be run over long distances.
There's a gain to be had converting HDV to uncompressed but you'd be better off capturing the HDV and doing it in software. You'll not improve the HDV much, a little chroma blur might help, but doing everything else uncompressed will improve overall quality. But again you're looking at HUGE file sizes.
Converting to a digital intermediate such as the one from Cineform is a much easier path to go down.

January 11th, 2007, 02:57 AM	#1
Trung Dau Regular Crew Join Date: Dec 2005 Posts: 51	capture uncompressed HD I'm doing the research of capturing uncompressed HD via HDV camera. The component analog on JVC HD100 and the HD-SDI output on JVC Hd250 only live uncompressed output. So my question is: Can we only capture while live shooting? CAN'T WE playback the HDV tape and capture it to uncompression hd720/60 4:2:2 ?

January 11th, 2007, 05:47 AM	#2
Rikard Holmstrom Tourist Join Date: Nov 2006 Location: Falkenberg Sweden Posts: 4	That´s right. if you want to capture a uncompressed stream you have to capture it live, while shooting. everything on tape will be compressed HDV.

January 11th, 2007, 09:45 AM	#5
Bill Ravens Join Date: Nov 2001 Location: santa fe, nm Posts: 3,264 Images: 10	if the signal is coming from the playback(tape) it has been compressed by mpeg to write it to the tape. the camera will decompress it to play back out the component ports, but, you've already suffered the unrecoverable losses of the initial compression to tape. that's unrecoverable.

January 12th, 2007, 04:11 AM	#11
Trung Dau Regular Crew Join Date: Dec 2005 Posts: 51	sorry i forget to post the link. http://www.convergent-design.com/hdm...CSI_manual.pdf on page 30 u see the color sample is 4:2:2 So what the purpose does Convergent Design and Miranda convert to uncompressed HD or SD for? So we can edit native HDV and export to any format we want, or u print the result to HDV tape and convert to uncompressed Hd by Convergent Design or Miranda.

January 12th, 2007, 05:34 AM	#12
Bob Grant Trustee Join Date: Nov 2005 Location: Sydney Australia Posts: 1,570	Those boxes are targeted at broadcasters who need to route HD-SDI and who only have a HDCAM workflow. We sold several to one network who only use HDCAM-SR, one hour of tape costs around $800 for those VCRs. They are well aware that they gain nothing converting to HD SDI, it's purely a workflow issue, plus the HDV footage gets intercut with the HDCAM footage. If you want to capture live from a HDV camera there's a number of ways to do this, Convergent Design have a new box that'll convert HDMI to HD SDI and there's a card from BlackMagic (Intensity) that'll do much the same for you. Bear in mind that you're going to need a very fast disk array to keep up and HDMI cannot be run over long distances. There's a gain to be had converting HDV to uncompressed but you'd be better off capturing the HDV and doing it in software. You'll not improve the HDV much, a little chroma blur might help, but doing everything else uncompressed will improve overall quality. But again you're looking at HUGE file sizes. Converting to a digital intermediate such as the one from Cineform is a much easier path to go down.