View Full Version : Uncompressed 8/10 bit for short movie


Nicolas Monniot
February 22nd, 2007, 10:34 PM
Hello,

With several friends, we all have experience in multimedia, we have decided to create a video production company in the aim to make short movies. Internet will be used as a launcher platform for our creations and DVD (Blu-ray or not) will be used to promote our products.

For the camera, we thought about Sony HVR-V1E for 2 reasons:
- 1080/50i and 25p
- and HDMI connector

According to what I've read in forums and websites, 25p seems a better and easiest choice than 24p for transferring HDV (uncompressed) to HDCAM.
And it's where HDMI comes.

According to the guys at Convergent Design (see link below), "HDMI supports uncompressed HD and SD in RGB 4:4:4 (8 bit) or YCbCr 4:2:2 (8/10 bit) and 4:4:4 (8/10 bit) in resolution up to 1080p".
It seems therefore possible to transfer HD to HDCAM for festival circuit projection or even to 35 mm.
www.convergent-design.com/hdmisipics/HDMI_in_HDV_and_AVCHD_Camcorders.pdf

Blackmagic has a new video capture card called Ïntensity" supporting HDMI in/output (for uncompressed video and audio), but without IEEE 1394 connection (for deck control and time code).
It's why I intend to use a Convergent Design HD-Connect MI and a Decklink HD Pro, to bypass the time code problem.

The editing software will be Sony Vegas 7 for a question of price and compatibility. But I am not sure if Vegas 7 supports uncompressed 10 bit.

What do you think about the V1E for what we intend to do?
What about 25p vs 24p for HDCAM transfer?
Do I need the Cineform codec even if I use uncompressed video?
Does everything I wrote make sense for you?

Nico

Marcus Marchesseault
February 23rd, 2007, 01:53 AM
First: There are existing discussions on this board about this procedure. Search the V1/FX7 forum.

You don't need HDMI to transfer HDV to HDCAM. Whoever does the transfer for you is the person to ask. It should be perfectly fine to use 50/60i.

If you want to record uncompressed video from the V1, you will need to record live to the computer. Once it is on tape, it is compressed and the HDMI port will only play that compressed video. Recording live to the Blackmagic card makes sense in the studio if you are doing chromakey, but you may find dragging a computer to every location difficult. Forget any shots where the camera moves significantly if it is connected to a computer that can record uncompressed video. I don't think you will want to have a dolly crowded with a high-end workstation with a RAID and some car batteries.

The V1 records everything in a 50/60i stream so it can be treated in many ways. Like I said, you probably don't need uncompressed for most shots. Depending on the speed of your computer, you can edit in almost any format you like. The native HDV mpeg2 files can be used if you have efficient NLE software (like Vegas) and a fast machine. Cineform is an intermediate codec that can be helpful to increase editing responsiveness and reduce loss in operations like color correction. It is not necessarily needed to edit HDV.

David W. Jones
February 23rd, 2007, 05:21 PM
Make sure you budget enough money for a RAID that is fast enough to do uncompressed HD, as well as large enough to hold all of your footage, render files, so forth.

Don Donatello
February 24th, 2007, 02:05 PM
V7 does NOT support 10 bit - it can play 10 bit but it's all processed at 8 bit.

if you are in the USA - why 25p? does 25p HD have more res then 24p HD ?

Ken Hodson
February 24th, 2007, 04:43 PM
His location says Australia!

For serious "shorts" why not consider a HD cam with removable lens (XL-H1 or HD-110/200/250) so you can adapt a 35mm lens with minimal light loss. For that pro DOF look.
It seems you will not be capturing to tape, but you will be tethered to a PC. In that case you may want to check out ProspectHD for uncompressed ingest. It's costly but probably less then the RAID you would need for 1080p24 capture.

Marcus Marchesseault
February 25th, 2007, 10:35 AM
"so you can adapt a 35mm lens with minimal light loss. For that pro DOF look."

It is not the 35mm lens itself that provides a shallow depth of field. It is the size of the imager. You would still need to use a lens adapter like the Brevis or Redrock M2 and lose light with whatever video camera you choose unless you get something like a 2/3" camera that costs tens of thousands.

Ken Hodson
February 25th, 2007, 11:36 PM
Yes that is what I was saying. Adapt a lens, which mean using an adapter. Sorry you got confused.
The 35mm adapters that go directly on the body (requiring a removable lens) instead of mounting onto the current lens, do not suffer as much light loss. Which is a major factor with all of these prosumer HD cams.
The JVC 200/250 series also have the ability to flip the image in the cam so it won't be upside down when shooting. I think this is a great feature and one obviously included for the indie crowd.

Nicolas Monniot
March 1st, 2007, 08:08 AM
My computer crashed !

Thank you very much for your answers.
I have to do a bit more research and will come back with more questions.
Cheers.

Nico