Cirrus Logic AccuPak: Difference between revisions
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* FOURCCs: CLJR | * FOURCCs: CLJR | ||
* Company: [[Cirrus Logic]] | * Company: [[Cirrus Logic]] | ||
Cirrus Logic AccuPak is a reduced precision YUV codec. | Cirrus Logic AccuPak is a reduced precision YUV codec. | ||
== Data Format == | |||
The AccuPak codec packs 4 Y samples and 2 C samples into 32 bits by representing each Y sample with 5 bits and each C sample with 6 bits. It is essentially a scaled-down method of coding YUV 4:1:1, where each group of 4 pixels on a line is represented by a luminance sample each but share C samples. | |||
Each set of 32 bits represents 4 pixels on a line: | |||
p0 p1 p2 p3 | |||
For each set of 32 bits, read left -> right: | |||
p3.Y = next 5 bits | |||
p2.Y = next 5 bits | |||
p1.Y = next 5 bits | |||
p0.Y = next 5 bits | |||
Cb/U = next 6 bits | |||
Cr/V = next 6 bits | |||
------- | |||
32 bits | |||
Thus, the first 5 bits represent the Y sample for the last pixel in the group of 4 pixels. | |||
[[Category:Video Codecs]] | [[Category:Video Codecs]] |
Revision as of 18:38, 29 January 2006
- FOURCCs: CLJR
- Company: Cirrus Logic
Cirrus Logic AccuPak is a reduced precision YUV codec.
Data Format
The AccuPak codec packs 4 Y samples and 2 C samples into 32 bits by representing each Y sample with 5 bits and each C sample with 6 bits. It is essentially a scaled-down method of coding YUV 4:1:1, where each group of 4 pixels on a line is represented by a luminance sample each but share C samples.
Each set of 32 bits represents 4 pixels on a line:
p0 p1 p2 p3
For each set of 32 bits, read left -> right:
p3.Y = next 5 bits p2.Y = next 5 bits p1.Y = next 5 bits p0.Y = next 5 bits Cb/U = next 6 bits Cr/V = next 6 bits ------- 32 bits
Thus, the first 5 bits represent the Y sample for the last pixel in the group of 4 pixels.