HELP:: Questions about SD-SDI, 4:2:2 and camera codecs

[jammiefreerider]

The first thing I want to know about is what SD-SDI or HD-SDI is. I think its uncompressed raw footage coming straight out of say EX1. Normally it'd be compressed by the cam at 35mbps and stored on SxS card but instead it goes straight to an ioHD to compress using ProRess (not sure what bit rate) so it can be edited on the fly. This is what I have worked out so far but I'm probably wrong so please correct me.

What else I dont know is what 4:2:2 means or 4:1:1. I know its got something to do with the uncompressed HD colour???? How does this relate to SD tape cams anyone can buy???

Sony use the MPEG-2 Long GOP codec to encode to the SxS discs at 35Mbps. Panasonic use DVCPro/DVCPro 50 and AVC Intra 100/50 both at 100Mbps and 50Mbps. Considering the EX1 and HVX201a are similar cameras that quite a difference in file sizes but what is the difference in quality of codecs. Whats best for what?

I would be much appreciated if you could explain these things to me. Thanks

 

[bigbossbmb]

SDI (both SD and HD versions) is just another connection type for carrying video and audio signals. It is digital and uncompressed.


4:2:2 and 4:1:1 are forms of color sampling. You can read all about it here.

I won't go into the differences between compression schemes, but just a heads up, the Panasonic 200a (or 201a) will not shoot AVC. That is only on the really high end Panasonics.