L64105 LSI Logic Corporation, L64105 Datasheet - Page 320

• Manufacturer Part Number: L64105
• Description: Mpeg-2 Audio/video Decoder
• Manufacturer: LSI Logic Corporation

9.9.2.4 OSD Storage Formats
9-28
R
MIX
Cb[3:0]
Cr[3:0]
As mentioned, each OSD area requires the header control information
and the data bitmap. If a color palette is not included in the header, the
OSD Controller uses the palette information that was last entered. An
OSD frame may contain two or more display areas. Each frame must be
stored as two interlaced fields.
The OSD Controller accepts two formats for the SDRAM storage of OSD
data, Contiguous OSD and Linked List OSD. The OSD Mode bits in
Register 265
Figure 9.16
In Contiguous OSD Mode, the OSD areas must occupy contiguous
locations in SDRAM, one for the odd fields and one for the even fields.
The host must write the beginning addresses of the two memory blocks
into the OSD Odd Field Pointer and OSD Even Field Pointer registers
(Registers 270 through 273,
pointers to start the OSD display and then updates them for every frame.
It ignores the OSDA bits in the OSD headers. A termination header must
be added after the data for the last OSD area. The termination header
should specify a start row (STARTR) below the last line of the display.
Video Interface
Note:
illustrates the two formats.
If Y = 4 (scaled to 16) and both Cr and Cb = 8 (scaled to
128), then the output pixel is black. In the special case of
a color palette entry Y = Cb = Cr = 0, the output pixel is
transparent and the underlying decoded video is displayed.
(Table
Reserved
This bit should be cleared.
Mix Enable
If set, the Mix Weight field applies to this color; otherwise,
the output data is 100% OSD.
Color Difference Y-B
Y-B color difference value with ITU-R BT.601 chromaticity.
This value is multiplied by 16 before being used by the
OSD controller.
Color Difference Y-R
Y-R color difference value with ITU-R BT.601 chromaticity.
This value is multiplied by 16 before being used by the
OSD controller.
9.7) specify which format the host has selected.
page
4-61). The OSD Controller reads the
[7:4]
[3:0]
9
8