Bt848 is a complete, low cost single-chip solution for analog NTSC/PAL/SECAM video capture on the PCI bus. As a bus master, Bt848 does not require any local memory buffers to store video pixel data which significantly minimizes the hardware cost for this architecture. Bt848 takes advantage of the PCI-based system’s high bandwidth and inherent multimedia capability. It is designed to be interoperable with any other PCI multimedia device at the component or board level, thus enabling video capture and overlay capability to be added to PCI systems in a modular fashion at low cost. The Bt848 solution is independent of the PCI system bus topology and may be used in a variety of system bus organizations: directly on a motherboard planar bus, on a card for a planar or secondary bus.
The Bt848A/849A are fully backward compatible enhancements to the Bt848. The Bt848A and 849A both include all the functionality of the Bt848, while adding support for peaking, single crystal operation, and digital camera support.

Distinguishing Features
• Fully PCI Rev. 2.1 compliant
• Auxiliary GPIO data port and video data port
• Supports image resolutions up to 768x576 (full PAL resolution)
• Supports complex clipping of video source
• Zero wait state PCI burst writes
• Field/frame masking support to throttle bandwidth to target
• Multiple YCrCb and RGB pixel formats supported on output
• Supports NTSC/SECAM/PAL analog input
• Image size scalable down to icon using vertical & horizontal interpolation filtering
• Multiple composite and S-video inputs
• Supports different destinations for even and odd fields
• Supports different color space/scaling factors for even and odd fields
• Support for mapping of video to 225 color palette
• VBI data capture for closed captioning, teletext and intercast data decoding

Additional Features in Bt848A/849A Only
• Supports peaking
• Requires only one crystal
• Digital camera support through GPIO port
• Support for WST decode (Bt849A only)

APPLICATIONs
• PC TV
• Intercast receiver
• Desktop video phone
• Motion video capture
• Still frame capture
• Teletext/Intertext
• VBI data services capture