Huge captures...noob asks why?

[vhelp]

My thoughts on Huffy..

I've seen it (during my captures) go to 3:1 compression. That might be
in its *lesser* of lossless capture mode. A 2:1 would mean that much
closer to lossless. And, a 1:1 *is* lossless
.
But, I've also seen where my *compression* number would vary during the
capturing phase. I thougth that it was odd that I should even be seeing
such a change during capturing. But, I figure it *is* part of the compression
of things during capturing - another

I'm going to be doing some capturing (huffy and other codecs) for my
own set of testings (elsewheres in the relm of things) and I will be
noting the compression numbers

About bbMPEG ...

I like to think of it as being a "transcoder" for audio

-vhelp

[BJ_M]

it is Variable compression .. and the YUV mode is higher than the RGB mode .. YUV is also not lossless ..

a lot of black or solid color will be higher compression ..

[lordsmurf]

BJ_M, it's 4:4:4 that's lossless, correct?

[BJ_M]

not nessessary , can still be lossy

[junkmalle]

[Huff]YUV is also not lossless

It depends on what your source is. EVery capture card I know of captures in a YUY2 (YUV) colorspace. If this is sent directly to HuffYUV then HuffYUV is completely lossless. If your source is RGB then the conversion to YUY2 loses color precision and color resolution.

[BJ_M]

YUY2 (YUV) is .... ah never mind ....

its to confusing ..

[lordsmurf]

Confuse me. Please.
I promise to not ask any questions. I'll look it up myself.
Just hit me with what you have. I can take it.

[junkmalle]

RGB, YUV, YCbCr, YUY2, etc. info:

http://www.doom9.org/index.html?/capture/digital_video_color.html

[BJ_M]

good guide above -- showing that subsampled video is in fact - compressed , color compression ..


the defacto paper on color in video

http://www.poynton.com/

http://www.poynton.com/notes/colour_and_gamma/ColorFAQ.html

[junkmalle]

good guide above -- showing that subsampled video is in fact - compressed , color compression ..


the defacto paper on color in video

http://www.poynton.com/

http://www.poynton.com/notes/colour_and_gamma/ColorFAQ.html

Nice site. I've added it to my reference list. He gives the transformation matrices for many colorspace conversions. The next time I need one I'll know were to get it!

[Wilbert]

I loaded my capture into TMPGEnc Plus and encoded it to SVCD twice ... same settings each time, the only thing I changed was that one encoding had the dreaded "YUV" option check marked whereas the 2nd encode had that damn option not check marked. I hate that ******* option.

Which YUV option are you refering to? 'Output YUV data as YCbCr not CCIR? This option should be unchecked in most cases. If checked it keeps the luma range when converting RGB to YV12 (ie RGB [16,235] -> YV12 [16,235] instead of the normal RGB [0,255] -> YV12 [16,235]).

Some of the DV codecs output RGB [16,235]. In that case it must be checked.