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-   -   4:4:4 12-bit Uncompressed DVX100 (https://www.dvinfo.net/forum/alternative-imaging-methods/20332-4-4-4-12-bit-uncompressed-dvx100.html)

Laurence Maher June 18th, 2004 02:15 PM

Say guys, I copied this from another thread:

Not sure if this will help or not but I found a codec for free that supports 16 bit per channel as well as an alpha channel making a 64 bit video codec. It works on mac and pc with just quicktime 5. Best of all it is free. They even have a lossless codec that can get 6:1 compression with no loss but that codec is $99.00. I know it isn't 12 bit per channel but it might be an easier way for people to manage files opposed to a series of stills. Besides right now the tiff files will need to be 16 bit anyways.


http://www.digitalanarchy.com/micro/micro_none16.html

Thomas Smet June 18th, 2004 02:40 PM

how did my post get into a different thread? For me it shows up right in this thread. I also posted a followup.

Thomas Smet June 18th, 2004 02:43 PM

http://www.digitalanarchy.com/micro/micro_none16.html

Jake Richardson June 22nd, 2004 07:07 PM

latitude
 
is the latitude of the normal dvx100 5 stops or 6?

what is the lat of the uncompressed version?

35mm cinema film is 13 stops?

thank you,

jake r.

Thomas Smet June 25th, 2004 04:11 PM

has this thread died?


Anyways if you are out there Juan I was curious as to how hard would it be to just get 8 bit uncompressed 4:4:4 off of the mod. I have been doing some tests and except for really fine color correction 16 or 12 bit video does seem a little over kill. Whenever I convert these sample frames down to 8 bit they still look amazing better than anything I have ever seen from a video camera. I did some keys at 16 and 8 bit and I can't tell the difference. Color correction did suffer a little bit but not much. The only time you would really need that much range for color is if you really screwed up shooting and you had crappy footage.

If this isn't possible then I guess I could just convert to 8 bit when everything is captured.

Stephen van Vuuren June 25th, 2004 04:13 PM

In my AE work, sometime moving to 16 bit really helps banding and gradations, other times, not at all. It really depends on the source material. I agree that 8-bit is easier, but if 12 or 16 bit is possible, I would still like to have the option to start their and move down.

Juan P. Pertierra June 25th, 2004 04:19 PM

Hi,

Nope, not dead, i've just been working non-stop, i guess it's a good time for an update.

I have the camera closed and completely assembled for the first time in over 6 months. The flex cable slides out the bottom perfectly. I have the hardware prototype all hooked up and i'm right now just working on the software configuration of the FPGA, which is what's left to be done. Once again, all the probing done to the camera was done with absolutely NO SOLDERING.

My plan once I get it done, is to get one or two units together and lend them out to people who can try them out and give me feedback on any suggestions or added features.

About the 8-bit video, that's easy. Hadling 12-bit is actually much harder because it doesn't align to word boundaries. My hardware allows the user to capture several different color precisions to save space.

I understand what you mean about the 8-bit video. However, the problem with DV footage is not really that it is 8-bit, but more like they compressed the 8-bit values to a smaller dynamic range, loosing latitude. With the XRS-1(random name for my device) you will still get the full latitude of the CCD, just decreased precision to 8-bits when set to that mode. At full quality it will give you uncompressed 16-bit RGB color files with 12-bit RGB precision.

I've been busy with this, but if anyone wants to see any more tests, just let me know what you want to see and i'll take them.

I still have all the ORIGINAL frames from the latitude test, so if you want I can color-correct some of the RAW ones at different exposures for comparison with the DV frames. Remember, all the RAW frames in the latitude test were not color corrected, so they don't even have white balance adjustments done.

Juan

Jesse Rosten June 25th, 2004 04:44 PM

Hey Juan,

If you need people to be beta testers for your mod... I would be more than happy to donate my DVX to the cause. :)

Jake Richardson June 25th, 2004 07:09 PM

latitude
 
So, what is the latitude of the
uncompressed dvx-100?

Thank you,

Jake Richardson

Juan P. Pertierra June 25th, 2004 07:10 PM

I'm probably not the right person to answer the question in photographic terms, i'm more of an engineer. But from looking at the latitude test results, it seems that there is a 2 F-stop difference between the optimal scene exposure for DV and RAW.

Can anyone else look at the images and see if you agree with this? I can post the original frames if needed.

Jake Richardson June 25th, 2004 07:35 PM

latitude
 
Thank you Juan.

Are you saying that your uncompressed dvx-100 has an additional two stops of latitude?

'Origin's exposure latitude is comparable to the best film stocks and offers at least 12 stops of linear response for an astonishing range in the whites as well as the blacks.
http://www.dalsa.com/dc/design/dc_sensor.asp

if this site says that the best film stocks are around 12 stops it would be interesting to know the latitude of your camera.

thank you,

Thomas Smet June 26th, 2004 01:16 AM

Hey Juan have you had a chance to check out this video codec?


http://www.digitalanarchy.com/micro/micro_none16.html

I am not even sure if it will work for real time recording but it seems like a very nice codec. There are two codecs. One is free and just does uncompressed 16 bit video. The other is $99.00 and does 16 bit video with a lossless compression that can get anywhere from 3:1 to 12:1 compression depending on the material.

Sorry if I keep going on about this. I wasn't sure if any of my old posts worked or not.

Juan P. Pertierra June 26th, 2004 01:30 AM

I haven't tried it yet, but I have read the specs and it seems like it will work for what we are doing. I guess as long as FCP and other programs don't have trouble reading the files with the codec, it's all good. It will help with the large number of files and sync'ing of sound.

Juan

Juan P. Pertierra June 26th, 2004 08:18 PM

Jake:

I'm not an expert in photography or exposure, but intuitively, since there are about two stops of difference from the optimum lighting for RAW and DV, i would assume that the raw footage has about two stops of additional dynamic range.

Can someone else post and say if this is correct or not?

Barend Onneweer June 27th, 2004 07:24 AM

MicroCosm Codec
 
Just a quick remark about the MicroCosm codec: although it's compression ratio for lossless compression is impressive, it's far from real-time. Both reading from and writing to the MicroCosm codec takes up a lot of CPU resources.

A better place to look might be the SheerVideo codec, which is supposed to do realtime compression and decompression of up to 10-bit (beta) video streams. http://www.bitjazz.com/

Support for 16-bit is supposedly on it's way.

Bar3nd


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