DV encoding bug in Vegas?

[_Al_]

Encoding NTSC DV avi 4:3 , gives some blocky artifacts in logo, not sure if it is some chroma bug or something, it is in red color only.

I downloaded picture of encoded logo and also original logo in PNG MOV video with alpha channel, so if someone would want to test it in Vegas it could be imported and enable alpha channel in media properties (media/alpha channels/straight - unmatted)

I also tested Cedocida DV export in Vegas with the same result, it looks like a bit better but obvious blocks of red were rendered as well.

[poisondeathray]

I get the same thing. It looks like point resized chroma, or some variation , of 411. You might have some lossy compression on top of that, mine were static backgrounds

(these are slightly different resized alpha overlays, but 1:1 crops, but it should be enough to convey the message)
vegas dv export


avisynth test point resize 411 chroma - this simulates 4:1:1 downscaling and back to RGB . I didn't use the chromain and out placement arguments for "dv" , but it should be good enough for the general idea. You can use dithertools to do precise chroma placement for "dv" samples

ffvideoSource("logo cut off with alpha channel.mov")
crop(480,0,0,0)
bicubicresize(720,480)
converttoyv24()
a=last

v=vtoy(a).pointresize(180,480).pointresize(720,480)
u=utoy(a).pointresize(180,480).pointresize(720,480)
YToUV(u, v)
MergeLuma(a)