Chroma-sampling and S-Video

[sps196]

Hi,

I feel sure this question would had come up before, but a few web-searches didn't seem to reveal a definite answer.

Does the S-Video output on the DVX100(BE) have the 4:2:0 chroma-sampling applied to it for "live" footage (not tape playback).

I've found some forum posts where people reported better keying from the S-Video port, but this could also be caused by the analogue conversion blurring the Y/C channels.

Sam

 

[David Jimerson]

S-video is analogue, so 4:2:0 chroma sampling does not apply.

 

[sps196]

I realise that the S-Video spec doesn't use any chroma sampling, but I suspect it depends at which point in the chain the S-Video is pulled. It's still going to be 4:2:0 if it's doing the digital to analogue conversion after the DV Compression stage.

i.e.

CCD
|
\|/
DV Compress ----> ADC ----> S-Video
|
\|/
Tape

Or:

CCD ----> ADC ----> S-Video
|
+----> DV-Compression ----> Tape

 

[David Jimerson]

It's fed out through S-Video after compression, so yes, it's an analogue feed of 4:2:0.

 

[sps196]

Doh!