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-   -   Please make inexpensive HDSDI recorder (https://www.dvinfo.net/forum/alternative-imaging-methods/44984-please-make-inexpensive-hdsdi-recorder.html)

Radek Svoboda May 21st, 2005 02:52 AM

Please make inexpensive HDSDI recorder
 
7 prosumer HD cameras, 1500-5,000 USD street price, with uncompressed analog HD output, maybe all outputs are 14 bit and can be converted easily to HDSDI.

Sony has already sold over 35,000 HDV cameras, added one in Qualia brand, is adding two more ones, all with uncompressed analog outputs.

Panasonic will have P2 camera with 1080p24 uncompressed output.

JVC HD100 HDV camera head will have 720p24-60 uncompressed output.

If you make such recorder that is popularly priced, I'll buy one, so will thousands of others. If you make 1000 USD on each, you'll make more in one year than in lifetime working for someone else.

I'm praying for some genius to make good money on me.

Radek

Obin Olson May 21st, 2005 08:48 AM

it can be done and I will work on it.

Radek Svoboda May 21st, 2005 10:40 AM

Obin,

Thank you. You're making this amazing camera that you started making before new low cost HD camcorders with uncompressed output. Your work is amazing. If you however want make some real money, concentrating on available cameras may be lot more profitable than trying create one. By year's end there will be probably 100,000 such cameras omong shooters, if 10% buy your recorder, and you make 1,000 USD each, it is 10,000,000 USD profit, probably in a year.

I think you should do some marketing reasearch, ask people here if they would buy your camera with recorder or camera that they can use for casual shooting and when need arives shoot uncompressed.

I paid for my FX1E less than raw industrial cameras cost. I would buy your recorder but not your camera with recorder, even though it may have better DOF, low light, etc.

Radek

Obin Olson May 21st, 2005 11:01 AM

your HDV camera is not even close to what we are working on, 8bit vs 12bit uncompressed vs compressed with DVD mpeg2 real lenses vs cheap prosumer lenses 2/3rd inch chip vs 1/3rd inch and the list goes on and on...

Obin Olson May 21st, 2005 11:03 AM

what it comes down to is movie/high end production vs prosumer high res video

Radek Svoboda May 21st, 2005 02:38 PM

http://www.computermodules.com/broad...onverter.shtml

Is this any good?

Keith Wakeham May 21st, 2005 05:56 PM

The hd10ad can get the componet yuv to hd-sdi. A little expensive, but it will work.

It is actually easier to implement hd-sdi along with a component yuv analog input into a recorder than having to convert to hd-sdi first. The recorder would have to convert the hd-sdi back to parallel digital anyway.

Radek Svoboda May 22nd, 2005 05:23 AM

It certainly seems there are people here that know how to do it. FX/Z1 camera A/D converter is 14 bit. CCD output is analog, then is digitized and converted to analog for uncompressed output? Am I right? But quality should be high enough because it comes off of 14 bit system. Am I correct?

Radek

Graeme Nattress May 22nd, 2005 06:38 AM

You've got to look at the noise figures though. Just because it's being digitized at 14bit or DSP at 14 bit doesn't mean that there's 14 bits of information there. I'd reckon you're lucky if there's the 8bits of information actually there, 10bits at most. Also, the analogue link will reduce resolution somewhat.

Graeme

Keith Wakeham May 22nd, 2005 08:51 AM

I'm almost 100% sure that the fX1, while the data coming off the ccds is 14 bit, what the component outputs is actually after the compression (so reduced down to 8bit and heavily compressed), so with the fx1 you can never get any higher quality than what goes to the minidv tape. Now other hdv cameras are different. The hd100u actually is uncompressed output and would greatly benefit. The Z1U, I don't know if they changed it so it actually output uncompressed instead of decompressed mpeg2 but i suspect it wouldn't be changed since its so similar to the FX1.

I think people really believe that analog is a big quality reducer, but in controlled enviroments it can be pretty amazing. Just take an analog lcd, running at native resolution but through analog, if you change a pixel colour, that colour doesn't smear into the next one and even if it does it will make minimal impact, a 1 - 2 shade difference.

I wouldn't go saying analog bad digital good, when the 1920 x 1080 frame is being compressed at 25mbits/second or 720 @ 19mbits and then ditch analog because its bandwidth is 1.485 Gbits/s but there could be a little colour bleeding.

Graeme Nattress May 22nd, 2005 08:59 AM

14 bit would imply a dynamic range of what, about 84db? I don't think CCDs have either that dynamic range or low enough noise levels to warrant that kind of quantisation. It certainly won't harm it, but sounds rather bit-wasteful.

Graeme

Keith Wakeham May 22nd, 2005 12:07 PM

it is indeed wasteful in some respect, but it doesn't stay 14 bit. But for all the digital processing it would be a bit more useful because it provides some more accuracy before the down resing it to 8 or 10 bit.

Just like it is better to work in 10 or 12 bit even if your final product is going to be 8 bit, it just gives you the little room before you have to output.

Graeme Nattress May 22nd, 2005 12:48 PM

Sure, processing in 16bit or floating point has great advantages, but we're talking about recording and digitising here, and there is zero point in recording a dynamic range that's greater than the noise floor of the analogue signal or else you'll be wasting disc space on noise.

Graeme

Keith Wakeham May 22nd, 2005 02:44 PM

I was never intending to say to record more bits than needed, just that analogue is not the almighty evil its made out to be by the corporations.

Until you see test waveforms on an oscilliscope it is impossible to say weather or not that the amount of noise on the analog outputs is to much. I've seen high frequency (Ghz range) analog waveforms on oscillascopes at my university, and over short runs (about a meter) the degradation is minimal and dac's could reproduce the exact signal produced by adc's with almost no error.

Their are to many variables in analog to just say it has to much noise. ADC's. DAC's, cable impedance, emf's, how the cables are arrange can affect the "noise".

Graeme Nattress May 22nd, 2005 05:56 PM

Analogue isn't inherently evil, but converting back and forth between A and D can lead to issues. Anyway, what I'm getting at are the inherent noise levels in a CCD and that 14bits is way more than you can really get off a CCD.

Graeme


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