Samsung S5PC110, Manual

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S5PC110_UM 6 5BMULTI FORMAT CODEC
6-7
6.2.2 FRAME MEMORY
A frame memory area is specified by base address, horizontal and vertical image size. A complete image consists
of Y, Cb and Cr components. The Cb and Cr pixels are stored in a byte interleaved way. Therefore, an image
needs 2 frame buffers, one for Y and another for Cb and Cr components, as shown in
Figure 6-2
. The sum of
image horizontal size and image horizontal offset should be multiple of 16: Horizontal offset makes the value of
horizontal size to be multiple of 16. The vertical image size for Cb/Cr frame buffer should be half of the Y frame
buffer.
Luma
(Y)
0 1 2 3
4pixel
Y Y Y Y
Chroma
(Cb & Cr)
4pixel
C
b
C
r
C
b
C
r
Figure 6-2 Luma and Chroma Pixel (8 bytes-aligned)
Reference picture is always made in the tile mode memory structure. Decoding reconstruction image is made in
64 pixels x 32 lines tiled mode. Encoding reconstruction image is made in 16 pixels x 16 lines tiled mode.
Current picture for encoding can be stored in two ways, linear memory structure or tile mode memory structure,
depending on ENC_MAP_FOR_CUR register (0xF170_C51C). Host sets external memory parameters with the
memory structure configuration. The physical memory address of each pixel data is determined by the memory
structure, base address, and coordinates of pixel in the frame.
Figure 6-3
and
Figure 6-4
shows the tile mode memory structure of a QCIF image for 16x16 and 64x32
configuration.