2.0 Functional Description
Fusion 878A
2.9 VBI Data Output Interface
PCI Video Decoder
2-26
Conexant
100600B
In the VBI frame output mode, VBI data capture occurs in the active video
region and includes all the horizontal blank/sync information in the data stream.
This feature can be used to provide a high quality still-capture of video. The data
is vertically bound beginning at the first line during VACTIVE and ending after a
fixed number of packets. The data stream is packetized into a series of
256-DWORD blocks.
A fixed number of DWORD blocks (434 for NTSC and 650 for PAL) are
captured during each field. This is equivalent to 111,104 DWORDs for NTSC
(434 × 256 DWORDs) and 166,400 DWORDs for PAL (650 × 256 DWORDs) per
field. The VBI frame capture region can be extended to include the 10 lines prior
to the default VACTIVE region by setting the EXT_FRAME register bit.
VDELAY must also be set to its minimum value of 2. The extended DWORD
block size is 450 DWORD blocks for NTSC and 674 DWORD blocks for PAL.
The VBI frame data capture occurs during the even field when the
CAPTURE_EVEN register bit is set and the COLOR_EVEN bit is set to raw
mode, and during the odd field when the CAPTURE_ODD register bit is set and
the COLOR_ODD bit is set to raw mode. The captured data stream is continuous
and not aligned with HSYNC.
Figure 2-18. VBI Section Block Diagram
YCrCb 4:2:2, 4:1:1
CSC/Gamma
8-Bit Dither
Format
MUX
FIFOs
Y: 70x36
Cb: 35x36
Cr: 35x36
# Dwords
DMA Controller
PCI Initiator
Instruction
Queue
Address Generator
FIFO Data MUX
PCI
Bus
Video Data Format Converter
VBI
Data
Analog
Video
ADC
879A_023