Subject: [AVT] Color subsampling in HDTV

From: Alejandro Cabrera Obed <[email-masked]>
Date: Tue, 8 Feb 2005 16:17:19 -0300

Hi people, 

I'm studing the HDTV uncompressed transmission over IP, and I'm
reading the "RTP payload format for uncompressed video". There is a
paragraph that says that in SMPTE 296 video format, in the case of
YCbCr components, the Cb and Cr components are horizontally
sub-sampled by a factor of two (4:2:2 color encoding).

I ask you: the digital representation of the color component samples
is 10 or 8 bits only for HDTV uncompressed ??? Because at page 2, I
read that "Samples may be coded as 8, 10, 12 or 16 bit values....can
you help me ???

Thanks a lot.

Alejandro

-- 
Alejandro Cabrera Obed
[email-masked]

_______________________________________________
Audio/Video Transport Working Group
[email-masked]
https://www1.ietf.org/mailman/listinfo/avt

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From: Ladan Gharai <[email-masked]>
Date: Tue, 8 Feb 2005 17:41:30 -0500

Hello Alejandro:

The draft "RTP payload format for uncompressed video"  describes a 
packetiztion scheme for uncompressed video in general. This draft is 
not specific to HDTV (examples of other video formats are presented in 
the introduction).

As such, the text on page 3, " samples may be coded as 8, 10, 12 or 
16..."  refers to digital video in general.

However, in regards to the 1080i and 720p HDTV formats, the respective 
SMPTE 296M and 274M standards discuss 10bit and 8bit samples only.

Ladan