4:2:2 or 4:1:1, how to check

ulisses

ulisses

Well-known member
Hello,

I'm doing some tests recording to the P2 in 480i / DVCPRO50...
I'm using the HVX component output cable to digitize in Quattrus board (4:2:2).

I'm not sure if the HVX is outputting in 4:2:2 via component from the P2, is there a way to make sure I have the footage in 4:2:2 color ?

Thanks,
Ulisses
 
The analogue signal is not 422 or 411 or 420 or whatever. These numbers refer at digital samples and an analogue signal is not digital. The camera is converting your DV50 422 data into a YUV analogue, no more colour samples, bitrates or other digital crap. At the other end, your capture card converts the image back into something that could very well be 422 again, or something else.
 
Ulisses has a valid question-

What he's asking is whether the signal sent via component is created from a 4:2:2 digital signal... It's valid since cameras which record 4:2:0/4:1:1 to tape will often send a pre-compressed (and pre-downsampled) signal down through the component, which will have a greater resolution preserved in the chroma then the signal downsampled onto tape.

To answer the question, the HVX does output with a high enough quality analogue signal to make 4:2:2 capture worthwhile. To check it, record some primary-coloured shapes against black/white, then compare that primary-colour-as-greyscale to the luma signal in your NLE...
 
I need to record some SD chroma-key footage, and the fast workflow I have now is using the HVX component output, so let me change the question... is it better to record to P2 card in DVCPRO50 than to DV tape, using the camera component output ?
My NLE works in YUV 4:2:2, but can't read MXF... I think the other option is to convert the MXF to MOV or AVI and import it to YUV .DPS format (the Quattrus file format). Anyway I have a high quality analog component input in my system.

I recorded same footage in DVCPRO50 and DV in the P2 card and digitizing via the component cable I couldn't saw a visible difference, but I'll try the primary colour shapes test.

Thanks again,
Ulisses
 
Good question - how it derives the component ouput would be on my mind also.

Pure speculation - but as it can output full 720p from the component (also 4:2:2) then you would expect the conversion is not meddled with in terms of colour sampling?

Film something that causes problems with RED (blocky edge) in both DV and DV50 and see if there is an analogue difference.
 
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