This may be a silly question...but!

[grovsnus]

Hello all! I've been playing around with XviD recently, and I like what I see!

I'm not an expert when it comes to the math behind mpeg-4, however, so bear with me..

I'm going to encode a lot of black & white movies, and I was thinking if it would be possible to do a special "B&W Mode" that would take into account the fewer number of colours? That should theoretically mean much better compression or at least much better quality at the same size.. Is this feasible at all? Would it have any effect whatsoever or is the number of colours irrelevant?

Strictly speaking, b&w content is 8-bit only, so one would think that big savings are in order.. Or?

I'd appreciate your thoughts on it, nonetheless :)

Keep up the good work!

[-g-]

[-h]

I'm going to encode a lot of black & white movies, and I was thinking if it would be possible to do a special "B&W Mode" that would take into account the fewer number of colours? That should theoretically mean much better compression or at least much better quality at the same size.. Is this feasible at all? Would it have any effect whatsoever or is the number of colours irrelevant?

I believe Isibaar and gruel looked at this (only encoding Y-values), but it didn't achieve much of anything :) If you encode normally (perhaps with a saturation filter set to 0% to make sure), you'll get a B&W encode.

-h

[Nic]

Neuron2 (Donald Graft) released an AviSynth filter that can control saturation...etc.

Maybe that will help?

-Nic

[Acaila]

Steady also created a grayscale filter once, you can just put that in your avisynth script to strip all color. It even makes nice B&W movies from a color source :)

[Teegedeck]

...don't want to sound tight but how about reading Doom9's statement on the use of meaningful subjects for new threads? :(

[grovsnus]

First off, yeah, I apologize for the stupid subject.. I should know better than write posts at 9am ;) Fixed now! :D

That filter sounds interesting! I'll see if I can find it somewhere and give it a try - thanks for the tip :)

[MaTTeR]

I've been getting pretty nasty B&W encodes as well so all of your tips are much appreciated.

Logically thinking I figured a dark B&W source would compress much more so than color. Every codec has proved me wrong though:)