Help with Van Helsing please

[OMINUS]

i am trying to encode the van helsing movie (not the anime)
but i have encourented an obstacle
the first 15min of the movie are in b/w and require about 4000kbps for a
good quality encode-the rest of the movie is coloured and require about 2000kbps for the same quality(ofcourse the resolutions are the same)
i want to use those 2 different bitrates for the movie (plus to enable grayscale encoding for the first 15min) and the rest xvid settings (qpel,trellis etc) enabled for the whole movie
i know that this can be done with the zone options but i cant understand
how-if u can tell me how exactly i must configure the zone options tab or at least point me to a relative faq i would be grateful

[jon.schaffer]

Add a new zone. You have now 2 zones in the list

Set the bitrate at 2000 kbps

Edit the first zone (select it and "Zone Option"):
- leave the starting frame at 0; check WEIGHT, and enter the value 2.00. This should multiply the choosen bitrate (left at 2000 kbps) by 2, i.e. 4000 kbps.
- check Greyscale encoding
- OK

Now, check the second zone and edit it:
- start frame: the frame from which the movie is colored
- weight: leave 1.00
- Check BEGIN WITH A KEYFRAME
- of course, do not check greyscale.
- OK

Now, you have 2 zones set up differently!
The first zone goes from 0 to the frame before the starting frame of the second zone...

Hope this helps,

Jon

EDIT: I never used the zone with different WEIGHTS (only Quantizers), so maybe someone will correct me for that...
EDIT2: this time I was faster, Ark ;)
EDIT3: added a precision to be clearer

[Ark]

Make 2 zones, one that starts at frame 0 (that will be the dark 4000kb section), and another that starts at the end of this zone (for 15 minutes the starts should be around frame 22500 if it's PAL and 20700 if Film NTSC) and go on 'till the end of the movie.

You can't directly set bitrate, but you can assign a quantizer for the zone or a weight, that is (if i remember well) related to the average bitrate calculated for the movie. With 1.00 you'll get the desired calculated bitrate. With 1.25 you'll get 25% boost in bitrate for that zone, otherwise with 0.75 you'll get 25% less bitrate.

All you have to do is guess what quantizer-weight achieve that 4000-2000 bitrate values...

EDIT: damn...jon's faster today...;)
EDIT2: Ok, jon's method is better.../me hiding in the dark/...:( ....:D

[ObiKenobi]

Originally posted by OMINUS
if u can tell me how exactly i must configure the zone options tab or at least point me to a relative faq i would be grateful

Just get the frame ranges for each of the 2 zones you want. Set the first zone to greyscale with a weight of 2. Set the second zone without the greyscale with a weight of 1. When you go to configure your second pass, leave the zones the same and set your target bitrate to 2000 kbps and this should give you the results you want.

[AsTimeGoesBy]

I have encoded 'Van Helsing' recently too, specially because of that b/w scene. ;)

- Maybe you also should set a much-lower-bitrate-zone for credits at the end of the movie.
As the beginning, the credits will consume about 150%-200% of the average bitrate. I have noticed that rather accidentally by separating the end-part with the credits.

- For my taste the video is originally 'too high'. My first encoding was at 720x408 (very close to PAL/16:9). But on TV (or PC at 1152x864 or even 1280x1024) a resolution of 720x392 looks much better - whells turn round, the moon is a proper disc and objects that subjectively should look like a circle really do.