Resize HD to SD

[ron spencer]

Can one just simply use spline64resize from 1920x1080 to 720x480 without any cropping? I want to put some HD footage on DVD. Is the resize enough as it is since will be encoded to DVD and flagged 16:9 as aspect

thanks

[jagabo]

Can one just simply use spline64resize from 1920x1080 to 720x480 without any cropping?

Yes.

[manono]

Unless it's 1080i and interlaced.

[yoda313]

Unless it's 1080i and interlaced.

Are you sure? I know that standalone dvd recorders record interlaced 480i. Shouldn't it be just as easy to go from 1080i to 480i?

And also I thought this was referring to resolution not progressive vs interlaced?

The important thing is to keep it 16:9 assuming that was the original aspect ratio.

(I could be wrong on the interlaced bit but I said my piece)

[jagabo]

Unless it's 1080i and interlaced.

Are you sure? I know that standalone dvd recorders record interlaced 480i. Shouldn't it be just as easy to go from 1080i to 480i?

No, if it's interlaced and you simply resize you will end up blurring the two fields together. You want to keep the two fields separate. A crude (but usually adequate) method that a lot of people use:

SeparateFields()
LanczosResize(720,240)
Weave()

In VirtualDub the equivalent is to Deinterlace (unfold fields side by side), Resize to 1440x240, the Deinterlace (fold side-by-side fields together). Or just use the Interlaced option in the Resize filter.

[ron spencer]

I figured that.....it is a progressive source so no worries...thanks for bit on interlace though....good to know!!!!

[PuzZLeR]

Done the same myself with great results (no distortion, great quality, no headaches) for 16:9 DvD production.

However I've used Lanczos instead of Spline. Any critique or agreement? Just curious.

[ron spencer]

lazcos is for upsizing in general

spline is for downsize

[edDV]

Can someone post short before/after clips for 1080i -> 480i 16x9? Some motion would be useful.

I want to compare to Cineform, Apple Intermediate Codec and stock Vegas resize.

[jagabo]

1080i TS file from Hauppauge HD PVR, converted to 480i with AviSynth+HcEnc.

http://www.sendspace.com/file/9optki

There's a little A/V sync error in the TS file.

AvcSource("cut.dga")
AssumeTFF()
ConvertToYUY2(interlaced=true)
SeparateFields()
LanczosResize(720,240)
Weave()
ConvertToYV12(interlaced=true)

Oh, I probably should have done a rec709 to rec601 adjustment too.