HDV to WMV HD - what bitrate to maintain quality?

[p6889k]

I need your help with the following encoding scenario:

Video Source:
Video capture from HV20 HDV camcorder in MPEG2 format 1440x1080 resolution
25mbps bitrate
(basically standard HDV 1080i capture)

Encoding Target:
WMV HD
1440x1080 resolution
?? bitrate

Question:
What bitrate and other encoding settings should I choose to maintain the video quality of the source file? I'm sure there's no exact formula, but at least a rough estimate would help.

Thank you.

[Sharktooth]

as you said there's no exact formula and even the rough extimate depends on the complexity of the source material.

[zambelli]

Are you planning to encode as interlaced or deinterlace first and encode as progressive?

If progressive, you can probably maintain great quality at around 10-12 Mbps average. If interlaced, you'll probably need a few megabits more. That's just my rought estimate - I haven't seen the footage so I can't tell for sure.

Try this wmcmd.vbs line:

Interlaced:
cscript wmcmd.vbs -input mysource.avs -output myoutput.wmv -v_mode 3 -v_bitrate 12000000 -v_keydist 10 -v_preset best -v_bdeltaqp 1 -v_dquantoption 2 -v_percopt 2 -v_preproc 18 -v_type 4
This assumes bottom field first. If the source is TFF, change v_preproc 18 to 17.