Hdmi 4:4:4 - Page 4 at DVinfo.net

Go Back   DV Info Net > Canon EOS / MXF / AVCHD / HDV / DV Camera Systems > Canon XA and VIXIA Series AVCHD Camcorders > Canon VIXIA Series AVCHD and HDV Camcorders

Canon VIXIA Series AVCHD and HDV Camcorders
For VIXIA / LEGRIA Series (HF G, HF S, HF and HV) consumer camcorders.


Reply
 
Thread Tools Search this Thread
Old February 5th, 2007, 10:19 AM   #46
Major Player
 
Join Date: Sep 2006
Location: London UK
Posts: 376
Quote:
Originally Posted by Thomas Smet
I have done some tests of the jpeg codec over the weekend and it really is amazing. I rendered some stuff from 3D Studio Max to create an uncompressed 1920x1080 segment and converted it to jpeg and compared the two by switching the top layer off and on in After Effects and they were very close.
Just to be sure when you say 'Jpeg' you do mean photojpeg don't you (and not MotionJpeg) ?

The nature of Jpeg compression means it is very reliant on the content you give it, but I would agree it is often visually lossless.

_______________


Instead of switching between two layers in After Effects to reveal any compression artifacting try this:

Stick the original into the timeline and the compressed version on the layer above.
Then apply the 'invert' plug-in to the compressed (upper) layer and set the opacity of this layer to 50%.

At this stage if both layers are identical you should be looking at a perfectly flat 50% grey image - if not any differences introduced by compression to the upper layer's file will show up as small aberrations.

To really get super forensic - pre-comp these two layers and apply a levels plug-in to the comp - then crush the black and white until the aberrations show up clearly.

**I have kept this simple - of course there are many other ways of doing it
Lee Wilson is offline   Reply With Quote
Old February 5th, 2007, 11:46 AM   #47
Major Player
 
Join Date: Jan 2006
Posts: 440
I'd be interested in the quality of the Blackmagic JPEG codec. They have the uncompressed codecs available for download but I don't think they have the JPEG codec available, am I wrong?

The Blackmagic JPEG codec captures at 12MB/sec and I tested QT Photo JPEG on an HV10 clip resized to 1920x1080 at 95% quality and it came in around 12MB/sec. Of course at 95% quality the image is outstanding.

Last edited by Wes Vasher; February 5th, 2007 at 04:18 PM.
Wes Vasher is offline   Reply With Quote
Old February 6th, 2007, 10:34 AM   #48
Trustee
 
Join Date: Mar 2004
Location: Milwaukee, WI
Posts: 1,719
Just go to the Blackmagic website and download the drivers for Intensity. It installs the drivers for the card but it should not hurt anything. With the Install you will get all the codecs for the PC including the AVI uncompressed codecs the jpeg AVI codec and the uncompressed Quicktime codecs.

The AVI jpeg codec is a variable bitrate codec which is why it is hard to pinpoint the exact level of compression used for each frame. It changes for how complex each scene is. For example bluescreen footage should compress very small because most of the screen is a solid color with very little detail. The more noise and detail in a shot the larger the file will be. No matter how complex however the video should always fit on a single drive.

I did another test yesterday. This time it was SD but it way live component captured to uncompressed and converted to the jpeg codec. Visually I could not see any difference at all. I mean no artifacts at all. Doing the difference adjustment to compare the two only showed a slight amount of added noise but it wasn't anything any human eye on the planet would ever be able to see. Especially when the footage is playing back at a normal speed. The footage was shot in front of a green screen and it keyed just as well as the uncompressed version. Clearly I need to so more testing but so far this codec seems to hold up very well for compositing. Just to note I shot this greenscreen footage very bad on purpose. It was very low light with a lot of gain and only one light causing shadows and uneven light spread across the screen. With well lit and shot blue/green screen footage I cannot see this codec holding anybody back in getting high quality results.
Thomas Smet is offline   Reply With Quote
Old February 6th, 2007, 11:41 AM   #49
Major Player
 
Join Date: Jan 2006
Posts: 440
Thanks for the tip Thomas. I contacted Blackmagic and that's what they told me also, they said datarates can range from 12-14 MB/sec for the JPEG codec. I was also able to see a sample and it looked very good to me.

I've been able to get excellent keys by taking interlaced HDV, magic bulleting and deartifacting it, and finally resampling to 960x540. I have found this resolution affords me an excellent image and very fast processing. So I'm thinking capturing Intensity video with the JPEG codec would be more than enough for my purposes. I think for the users of the HV20 it'd be a good solution. If I could afford an XH-A1 then I could afford a handful of drives to capture uncompressed, but for now that's out of the question.

The next issue would be image quality loss in the pulldown removal process. Would the video have to be re-encoded with another JPEG pass when removing the pull down? For FX shots I would remove the pull-down and export to Tiff sequences but if I wouldn't edit an entire video with uncompressed footage.

The JPEG compression is also done by the CPU and not on the Intensity card according to Blackmagic, which I asked them about.
Wes Vasher is offline   Reply With Quote
Old February 7th, 2007, 10:51 AM   #50
Inner Circle
 
Join Date: May 2003
Location: Australia
Posts: 2,761
Quote:
Originally Posted by Thomas Smet
Also the Intensity card is a PCI Express X1 card and it wouldn't have enough bandwidth for 4:4:4. I think using PCI Express X1 makes it easier for a lot of people to use these because not everybody has a X4 slot or larger on their motherboards.
The data rate is close to 266MB/s. The new version of PCI-E is to be around 533MB/s for an single lane (let's hope they replace USB 2.0 with it (there is an external device version)).

HDMI 4:4:4 is not impossible on cameras, Version 1.3 supports it, but it seems the cameras are an in between version. What we really need is an single chip mode (complimentary and RGB/Bayer etc) that would save three times over 4:4:4 (I wonder if an differential 4:4:4 could be possible). The data would then come in an smaller native format before compression. I knew an guy once, that was trying to specify an HDSDI bayer format.
Wayne Morellini is offline   Reply With Quote
Old February 7th, 2007, 11:26 AM   #51
Trustee
 
Join Date: Mar 2004
Location: Milwaukee, WI
Posts: 1,719
Wayne I think the card needs that much because it does in and out at the same time. Therefore it would need to be able to push 240 MB/S just for 4:2:2 due to a stream in and out of the card if you want to monitor what you are capturing.

While PCI Express may increase the bandwidth in the future that doesn't help those who already have systems built. The Intensity card is clearly aimed at a lower end market of those who already have decent systems and want to add in a card. If you want 4:4:4 you can move up to the Declink Studio card. I'm not sure if the HDMI will do 4:4:4 but the component will. Even if the HDMI did 4:4:4 the jpeg codec will not. The only codec that could be used right now for compression would be photojpeg at 100%.

I do agree with you that it sure would be nice to have a bayer based video format kind of like how the Cineform version works for the Silicon Imaging camera. By recording the bayer pattern we would get data equal to 4:2:2 but with video that would be easier to convert to 4:4:4 with the correct bayer processing. In order for this to work however a camera would have to be designed to push a bayer pattern out of the DSP which no video camera will do so this is a little pointless right now.
Thomas Smet is offline   Reply With Quote
Old February 7th, 2007, 11:06 PM   #52
Trustee
 
Join Date: Aug 2003
Location: Vancouver BC Canada
Posts: 1,315
I really like what this Blackmagic Intensity and new HDMI cams bring to the market. I just wish it could be incorporated into a laptop. I am a big fan of HDVrack type monitoring, is there anything like this available for a solution like this?
__________________
Damnit Jim, I'm a film maker not a sysytems tech.
Ken Hodson is offline   Reply With Quote
Old February 8th, 2007, 07:30 AM   #53
Inner Circle
 
Join Date: May 2003
Location: Australia
Posts: 2,761
Thomas, I know that they have separate path for each direction, is it for sure that the bandwidth is split between the two paths? You could use component for monitoring.

HDMI 1.3 does support 4:4:4. 1.2x had extensions, but I am not sure wherever that included 4:4:4.

I read Jpeg supports 4:4:4 above something like 80%, doesn't it. You can use whatever codec you want with it.

I think there will be cameras out there already that could reconfigure their outputs to be grey-scale bayer, or some other pattern. But it is really an industry suggestion, because it would make sense from the production side, and even on the distribution display side. If they could use something like HDMI as the basis for an general I/O interface, it could handle most things and new devices. I used to advocate HDMI as an possible target for USB 3.0 (10.2GB/s versus 480Mb/s, but with more host independent I/O management like Firewire and USB GO (but preferably not, Firewire was better)). But now I realise that the external desktop bus version of PCI-Express (finally coming) is probably meant to be this, but need to be plug and play like firewire and preferably much faster like modern HDMI speeds).
Wayne Morellini is offline   Reply With Quote
Old February 9th, 2007, 09:38 AM   #54
Inner Circle
 
Join Date: May 2003
Location: Australia
Posts: 2,761
In coincidence, information on the external PCI-E cabling has just come.

http://www.theinquirer.net/default.aspx?article=37528

Looks a bit more than would be cheap for USB3.0, but still a start in the smallest version.
Wayne Morellini is offline   Reply With Quote
Old February 9th, 2007, 02:07 PM   #55
Major Player
 
Join Date: Sep 2006
Location: London UK
Posts: 376
Quote:
Originally Posted by Wayne Morellini
I read Jpeg supports 4:4:4 above something like 80%, doesn't it.
100% supports 4:4:4

Below 99% supports 4:2:2
Lee Wilson is offline   Reply With Quote
Old February 11th, 2007, 08:44 PM   #56
Inner Circle
 
Join Date: May 2003
Location: Australia
Posts: 2,761
That's right, below 80% is 4:2:0? What's the compression ratio at 4:4:4 again?
Wayne Morellini is offline   Reply With Quote
Old February 12th, 2007, 12:32 AM   #57
Trustee
 
Join Date: Mar 2004
Location: Milwaukee, WI
Posts: 1,719
below 75% is 4:2:0. Photojpeg quicktime files are usually captured as 75% because that is the starting point for 4:2:2 color. Anywhere between 75% and 99% is 4:2:2. This only applies to mac users however. The AVI codec cannot be adjusted and it adjusts itself based on the footage.

On another note some of you may have noticed that Cineform just announced support for the Intensity card. This means those of you using Premiere and Cineform now have another codec to use on the PC. Of course the Cineform codec and software costs lots of money but if you have it that is great. Those of you already using Cineform to edit HDV will have files that are the exact same size on your hard drive but much higher quality if captured live over HDMI. The AVI files captured live will be the same size and work exactly the same as video captured as HDV. This means your level of workflow will be exactly the same. The only bad part is that right now the Intensity card will not work for live HDMI output from Premiere with the Cineform files but I guess that should change in the near future. So if HDTV live output is important you may want to stick with the jpeg codec for now until the drivers are updated.
Thomas Smet is offline   Reply With Quote
Old February 26th, 2007, 01:33 PM   #58
Major Player
 
Join Date: Nov 2006
Location: Victoria BC
Posts: 400
Quote:
Originally Posted by Wes Vasher
I've been able to get excellent keys by taking interlaced HDV, magic bulleting and deartifacting it...
Wes, how are you "deartifacting" the HDV footage? If with Magic Bullet, how?
__________________
Mac + Canon HV20
Robert Ducon is offline   Reply With Quote
Old February 26th, 2007, 02:19 PM   #59
Regular Crew
 
Join Date: Jun 2004
Location: Pavilion, USA
Posts: 64
Do we know if the signal coming out of the hv20 is 10bit or 8bit?
__________________
Whatever works
Rob LaPoint is offline   Reply With Quote
Old February 26th, 2007, 05:43 PM   #60
Major Player
 
Join Date: Nov 2006
Location: Victoria BC
Posts: 400
Having problems - and I think it's a simple answer as I don't mean to hijack the thread further than it already has been.

Just wondering what preset to use to transcode my HDV project to a JPEG-based one.

I just exported an HDV clip I had in FCP to a QT movie and chose the preset "Blackmagic HDTV 1080i 59.94 - JPEG" and there was no option for the percentage of compression. There was no 90%, 75% or 100%. And, it looked like crap in the end - macroblocks.

Now, should I have just chosen "Photo - JPEG" or "Motion JPEG B" or "JPEG 2000"?

I want great 4:2:2 quality with little or no perceived digital grain or artifacting (no gradient banding) - and space savings of course when compared to uncompressed. I have a Decklink HD card, so if there is an advantage to using a Blackmagic Codec, I will.
__________________
Mac + Canon HV20

Last edited by Robert Ducon; February 27th, 2007 at 01:55 AM.
Robert Ducon is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Canon EOS / MXF / AVCHD / HDV / DV Camera Systems > Canon XA and VIXIA Series AVCHD Camcorders > Canon VIXIA Series AVCHD and HDV Camcorders

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 08:31 PM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network