Aliasing and the DVCPro-HD codec

[araujofh]

Hello folks,

After watching the clips shot with the HVX200, I have noticed the the images were really clean.
Now, since the DVCPro-HD codec has a higher compression than the DV codec, shouldn't we expect some aliasing in the footage as well?
If the same clips were shot with the DVX100, for instance, we would have seen some aliasing.

What makes the HVX200 or Varicam footage so clean? Is it the codec itself?

[lazarus1907]

I'm not an expert, but I think that DVCPROHD records 1280 Y samples and 640 Cr & Cb samples per line rather than 720 Y and 360 Cr and Cb, so maybe the luminance channel is being compressed a bit more, but the chrominance resolution is better. However, DVCPROHD uses in total 3.33 times more uncompressed samples than DV, but since the stream is 4 times larger, you get roughly the same number of compressed bits per sample on either system (plus a much better color resolution in HD), which it's probably around 40 bits/sample/second after compression in either one, I think.
If I'm wrong I 'm sure someone will correct me soon anyway :)
Regards,

[Xenophon]

DV NTSC 16:9 with anamorphic converter is 720x480 with 180x480 color samples.

DV NTSC 16:9 letterboxed is 720x360 with 180x360 color samples.

1080p on NTSC HVX (true 16:9) is 1280x1080 with 640x1080 color samples.

and 1080p on PAL HVX will be 1440x1080 with 720x1080 color samples.

No wonder 1080p can resolve a lot more.

[araujofh]

Thanks guys!