encoding @ 16 bits instead of 24

[predatorian]

Hi, i once heard that the amount of space needed for a second of a movie, was calculated as: resolution times fps times color depth.
Color depth is always 24. In my opinion that's a waste. Why can't we use 16 bit (still 16 million collors) instead! Wouldn't that save bitrate for more important things? If someone can help me with this one it would be very nice. Sorry if it's a bit hard to read, my english isn't that good :sly:

Thanks a lot!

[bb]

I'm pretty sure you'd get a considerable quality loss. But it may be interesting for anime.

bb

[DJ Bobo]

16-bit is crap, for normal movies *AND* for anime.

and 16-bit was never 16,7 million colors. 16-bit = 65536 colors only!

Don't ever ever reduce the color depth to 16-bit.
This will give you *ONLY* quality loss and no compressibility advantages!

[predatorian]

HM, i see your point, looked it up myself and you do make sense :p
I'm trying to encode dbz episode 230 @ 512-384 precise bilinear. Results are useless. Bitrate = 1580. Looking for an extra thing that could help me save bitrate.

[-h]

Filtering will save you bitrate, as will better motion estimation (i.e. XviD). Or a more severe fDCT (i.e. ffmpeg).

The colour depth of the input is unimportant, since the data is passed through a DCT which ignores the depth anyway. All that removing colours would do is create harder edges which increase AC coefficients, thus requiring *more* bits to store.

-h

[predatorian]

I'm using more filters then i have fingers on my hands. I stick to divx 5.02 by the way, but if anybody have tricks that can save me, please drop a line

[DJ Bobo]

@ predatorian
Just want to remind you, that the FUNi DBZ DVDs already have crap compression (low bitrate CBR encoding and interlaced instead of progressive). You'll see artifacts all over the place *ON THE DVD*. So don't expect your DivX rip to get perfect quality ;)

[bb]

Originally posted by DJ Bobo
16-bit is crap, for normal movies *AND* for anime.

and 16-bit was never 16,7 million colors. 16-bit = 65536 colors only!

Don't ever ever reduce the color depth to 16-bit.
This will give you *ONLY* quality loss and no compressibility advantages! Very true. When I said it *may* be interesting for anime, I was thinking of a special codec, not MPEG-4 (I had that in my mind, but I should have written that, too :rolleyes: ).

bb

[michaelsez]

i just a quick scan through my collection and have a couple of movies at 16 bit. They seem to look fine to me(wouldnt have known if i had not looked it up). If anyone knows anything about this it would be great to play around with to try myself.

[Acaila]

The movies you have at 16 bit are probably encoded with DivX4 or a similar codec which also has the same effect. The effect I'm talking about is that when encoding a movie with DivX4 and VDub on fast recompress mode produces a 16 bit movie, VDub on full processing produces a 24 bit movie. This is infact a fake colordepth and both types are 24 bits in reality, that's why they still look great to you.