VHS to 1/2 D1 processing

[Dosdan]

I'm doing PAL VHS -> miniDV passthrough -> 1/2 D1 -> TMPEGenc -> DVD on a XP1800 Athon with 1GB.

1. Is Bilinear resizing the best resize to use when doing a simple 704x576 -> 352x576 resize considering speed, compressibility and visual artifacts?

2. In TMPGenc, I'm using 2-pass VBR and want to fit about 160 mins on a DVD. My last VHS transfer was 183 mins and it came out OK at 1/2 D1 resolution. I think the avg bitrate will be around 3300kbps but, with 1/2 D1, should the max bitrate allowed be around 8000 (I know you can go higher if you compress the audio more but I want to maintain compatibility) or 4000?

SetMemoryMax (512) 
LoadPlugin("f:\windows\system32\Convolution3d.dll") 
# PAL VHS -> S/AV input passthrough on a miniDV -> AVI2 
#  splitting automatically after every 12000 frames 
#  (8 mins at 25fps). 

SegmentedAviSource("Y:\Movie.avi") 
#SegmentedDirectShowSource("Y:\Movie.avi",25) 
# Using Panasonic codec, colourspace is RGB32 
# With SegmentDirectShowSource, Codec is MS 
#  and colourspace is already YUY2, but it 
#  seems much slower to load. 
# Now 720x576 

ConvertToYUY2(interlaced=true) 

#Crop(L,T,R,B) 
Crop(12,4,-4,-12)  
# Remove VHS switching noise & dark areas 
# Now 704x560 

SeparateFields() 
odd=SelectOdd.Convolution3D(0, 32, 128, 16, 64, 10, 0) 
# same as vhsBQ preset 
even=SelectEven.Convolution3D(0, 32, 128, 16, 64, 10, 0) 
Interleave(even,odd) 
Weave() 

BilinearResize(352,560) 

#AddBorders(L,T,R,B) 
#Try and keep each a  multiple of 16 for compressibility 
AddBorders(0,0,0,16)    
#Now 352x576

[GeorgeW]

Are you frameserving the resolution reduction and cropping into TMPGenc? I think you can just use TMPGenc to do both the crop and resize.

[Dosdan]

Yes, I'm frameserving. I thing resizing in Avisynth is faster then in TMPGenc. I remeber timing this at some stage because I had a 3 hour tape to work on. And I find it easier to setting everything up in an AVS file. I like using Ctrl-T (Insert Trim Set) to dump a trim range into VirtualdubMod's script editor and then pressing F7 to save and reload the AVS file back in VdubMod. Makes it very easy to see the changes.