Can You Capture HDMI at 1080p24?

[David Ziegelheim]

Originally Posted by Thomas Smet

I'm not sure what is going on with the specs either but I do know there were lots of complaints about banding in earlier HDMI specs. The website does clearly say that specs before 1.3 were limited to 24 bits.

quantization is different then color sampling so maybe that is where some of the confusion is. DVD encoding uses a quantization of 9 or 10 bits but the color is still 8 bits.

As for that chart are you sure that isn't the chart for the 1.3 specs?

Both table and diagram are from the 1.0 spec. For YCRCB with 4:2:2 they used 24 bits to get upto 12 bit quantization. Channel 0 is divided into 2 4 bit channels. Y is on 1/2 channel 0 and channel 1. CB abd CR share 1/2 channel 0 and channel 2. 12-bits.

RGB was limitied to 8 bits in HDMI 1.0.

[Thomas Smet]

Originally Posted by Gene Latimer

So, my primary question with all of this: What is the consistent formatting for integrating both live HDMI footage and HDV recorded tape footage? Do I simply capture the taped material via the Intensity card as well and, even though it's lost some elements compared to the non-taped material, it's all in the same format for editing?

What about later bringing in a few short pieces of DV from a DVCAM deck -- what is likely to be the best scenario for getting the DV footage into the same HD format as what I've described?

If you use a Intensity card with Adobe Premiere Pro you can mix HDV and mjpeg material in the same project. So you can record from tape as HDV or as mjpeg if you want to. For live stuff that needs to be higher quality such as bluescreen work then you capture live as mjpeg while recording a tape as well for backup. This way if your harddrive dies you at least have something you can go back to so you do not have to do the shoot all over again.

You can capture your tapes through HDMI but the quality will not get any better then what you would get through firewire. The fottage however may be easier to edit and use in 3rd party software that cannot load a HDV file. Capturing through HDMI will end up being just like using Cineform to edit with. With Cineform you capture the video through firewire but it gets converted to a format that is easier to edit and takes up more space than native HDV. The HDMI is basically doing the same thing except the conversion from mpeg2 takes place in the camera and then sent through the HDMI and saved as a mjpeg file which should be pretty close in quality to what Cineform gives you. The wavelet based codec from Cineform may be a little bit better but it also doesn't give you the option of capturing live uncompressed video that way either. Cineform's main format is limited to firewire capture. Cineform does have a higher end format that works with AJA capture cards but the cards and the codec are very expensive and will cost you more like $2,500.00 and not $250.00.

If you will be using the Intensity on a Apple FCP system then you have always had other codecs to use. You can capture to photojpeg(which is for the most part the same as mjpeg), DVCPROHD or the Bitjazz codec. All of these give you better quality than HDV.

If you use Avid Liquid I can tell you from testing out the new mjpeg codec that it works in realtime as a native format in Liquid. You can mix firewire captured HDV and mjpeg captured HD in the same project and as long as you have a good system it will all be in realtime. The problem however is that the only capture program that is currently supported by Blackmagic to capture mjpeg AVI files in Adobe Premiere Pro. Blackmagic has their own capture program but it only captures quicktime files. You will have to find another directshow based capture program to capture from the Intensity card as a mjpeg AVI file.

Oh by the way the new codec is mentioned a few times in the information on the Intensity card on the Blackmagic website.

When talking about editing in Premiere it talks about using compressed codecs such as mjpeg.

In the quality section it talks about using dv100 on Apple or the new jpeg based full resolution codec on Windows platforms.

The other interesting point is that nowhere does it ever mention capturing 10 bit video with the Intensity. Now the other Blackmagic cards can and it is listed many times in the descriptions of those products but Intensity never mentions 10 bit video.

You will also notice that Intensity is a PCI express x1 card. Every other HD card from Blackmagic has been a PCI express x4 card. PCI express x1 has enough bandwidth for 8 bit yuv HD but it would never cut it for 10 bit uncompressed HD video. This is why PCI express x4 is needed for the other products since they can capture 10 bit video. This makes me feel as though the Intensity really is a 8 bit only capture card regardless if a camera outputs 10 bits or what specs are used. Blackmagic has another card that has HDMI and component inputs that costs $995.00. This card does need PCI Express x4 and does 10 bit video because of the component inputs.

You can also get information on the mjpeg codec by going to the support section of the Blackmagic site and searching for the only document for the Intensity card they have right now which is titled "Which compressed codecs can I use with DeckLink cards?"

[Gene Latimer]

11 MB/s of mjpeg = 40 GB/hr. I'm shooting a feature with two-cameras -- editing in FCP on a new Mac Pro, which will hold 3 additional 500 GB SATA drives.

Adding those three drives might be the simplest way to start but that won't be enough for my project. What are the most economical and effective products for holding several TB of external storage?

[Tony Tremble]

Originally Posted by Ainslie Davies

According to Thomas..
...so just 8bit - 1920x1080 4:2:2 though which is lovely, If I could only come up with a workable portable HDMI recording system, I guess a full PC would work... damn AC power

I hope someone will produce a laptop HDMI capture system. An Expresscard 34 HDMI capture card and bus powered FW800 drive would be an awesome combination for chromakey work in a studio. Or even some location work with suitable power.

Vydeo.com are developing a HD-SDI capture card for Expresscard34 so it's not too much of a leap of faith to think a HDMI version could be in the works.

It could be a baby Wafian!!!

TT