about 10bit question

[rulv]

hi, Long time I can't visit this site, cuz my work was going so hard.
yeah, i know i'm shameless, but i need a help to doom9 members.

Recently, I could know about 10-bits x264 encoding.
even i had a short time that did a few encoding and experiment about 10-bit encoding, it worked properly, and also that works worked good in decoding through media player (i.e MPC-HC or KMPlayer)
but, I found a strange point. plz look at the below

Format/Info : Advanced Video Codec
Format profile : High 10@L4.1
Format settings, CABAC : Yes
Format settings, ReFrames : 4 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 2mn 38s
Bit rate : 4 811 Kbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate : 23.976 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 10 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.097

I don't know why "Chroma Subsampling" show not 4:2:2 but 4:2:0.
if Chroma Subsampling show 4:2:0, Should Bit depth indicate "8bit"? I understood that if Not having a 10-bit oriented moniter panel, the bit depth is downsampled from 10-bits to 8bits and also change a Chroma Subsampling, regardless of Source's bit depth.

Am i understanding a 10-bits mechanism wrong?
it will be very helpful if you answer about this question.

Thx.
Newbie :( - rulv

[J_Darnley]

10-bit refers to the bit-depth per sample, chroma subsampling refers to how the chroma is scaled to reduce its resolution. 10 bits for every luma and chroma sample. 4:2:0 means you have 1 chroma sample (U and V or Cb and Cr) for every 2x2 luma samples.

[rulv]

10-bit refers to the bit-depth per sample, chroma subsampling refers to how the chroma is scaled to reduce its resolution. 10 bits for every luma and chroma sample. 4:2:0 means you have 1 chroma sample (U and V or Cb and Cr) for every 2x2 luma samples.

I understand that a Bit Depth indicate just bit-depth per every Luma&Chroma sample.

So, aside from bit depth per sample, How Chroma Subsampling itself is determined that situation?
Its way of configuration exist in x264 option? or is it vary depending on original source?

[J_Darnley]

Different sources can have different chroma subsamplings, but you can now tell x264 what you want it to use, 420 or 444. 422 is not yet supported but is being worked on (IIRC). [EDIT] Most content that you will encounter is 420

[rulv]

Different sources can have different chroma subsamplings, but you can now tell x264 what you want it to use, 420 or 444. 422 is not yet supported but is being worked on (IIRC).

REALLY Thx for your answer :D

and I have a more question that irrelevant about it.

The question is connected to AVC level matter.
I already know a AVC level is relevant to compatibility between devices which whatever they are and media files, and also know it support a high framerate and a more high resolution media files.
Simply, supposing that I use completely equal source, so when that situation I want to know whether a advantage would there be in a highest level encoding media or files.

it seems that I'm giving you a tiresome taxing, but if you okay, it will be very grateful if you answer this question.

Thx.

[J_Darnley]

Usually you can just ignore levels. They are mainly for hardware compatability. They limit frame size, frame rate and max bitrate (and some others). If you were to strictly follow levels, then increasing it would allow for more quality. Since you can get good quality with 3 for SD and 4 for HD, there would be little point in worrying about whether you need to use higher.

x264 tells you what level it sets in the header when it starts encoding and will warn you if you set a level and some limits are crossed.

P.S. In my previous post I forgot to say that most content is 420. Edited.

[rulv]

Usually you can just ignore levels. They are mainly for hardware compatability. They limit frame size, frame rate and max bitrate (and some others). If you were to strictly follow levels, then increasing it would allow for more quality. Since you can get good quality with 3 for SD and 4 for HD, there would be little point in worrying about whether you need to use higher.

x264 tells you what level it sets in the header when it starts encoding and will warn you if you set a level and some limits are crossed.

P.S. In my previous post I forgot to say that most content is 420. Edited.

Thx for your kind explaination ^)^
your answer is effected to me Invaluably.

I hope you c ya later, good luck to all your life :D