saa7173 NXP Semiconductors, saa7173 Datasheet - Page 2

• Manufacturer Part Number: saa7173
• Description: Analog Video Stereo Decoder
• Manufacturer: NXP Semiconductors

SAA7173
Analog TV video and stereo decoder for computing and consumer applications in North America and Japan
Analog TV video capture and decoding
Analog video is sampled through five video inputs, supporting any
combination of CVBS and S-Video signals from TV tuners and
devices such as analog VCRs and camcorders. The SAA7173 auto-
matically detects 50- and 60-Hz field frequencies and all analog TV
video standards (PAL, NTSC, and SECAM). Video is digitized by
sophisticated, low-noise, nine-bit ADCs with built-in white and
color peak control, clamping, and programmable gain control.
Support for 27-MHz oversampling, twice the ITU-601 standard,
ensures an exceptional signal-to-noise ratio for maximum picture
clarity. Additional features include single crystal support for all
video standards, ultra-fast frame lock (for fast input-switching in
surveillance applications and VCR fast search, shuttle, and freeze
frame), and forced-field toggle (for non-interlaced inputs to avoid
VCR ‘blue screen’).
The SAA7173 decodes composite video into ITU-601-compatible
component color values. Its high-quality, multi-standard, adaptive
four-line comb filter performs best-in-class luma/chroma separa-
tion of CVBS signals from all sources, significantly reducing dot
crawl and enhancing image resolution and detail.The decoder
integrates separate brightness-contrast-saturation circuitry for
CVBS, S-Video, and raw VBI samples and hue control for CVBS
and S-Video signals.
Typical SAA7173 configuration for an USB dongle add-in card
CVBS
S-Video
audio
audio
line-in
antenna
or cable
USB TV DONGLE
TV TUNER
SAA7173
ITU/VIP
I
2
I
2
C
S
ENCODER
MEMORY
MPEG-2
S e m i c o n d u c t o r s
USB BUS
The SAA7173 supports fully automatic, three-level hardware
Macrovision detection with active-status interrupt. By ensuring
the content's original analog copy protection is still intact,
Macrovision prevents unauthorized recording of copyrighted
material transmitted through analog video outputs in applications
such as time-shift or archive recording or large screen display.
Video scaling, matrix, clipping
The SAA7173 incorporates an adaptive filter and circuitry to
crop, scale, and reduce frame rate. It can perform horizontal or
vertical video down scaling or zooming to support playback
windows of any size.Two alternating settings for active video
scaling support independent capture and preview definition.
Adaptive anti-alias filters reduce board space, system costs, and
external components.
Optional YUV-to-RGB and RGB-to-YUV matrices and a color
lookup table can be used to normalize ITU-standard color values
to the full RGB range and apply gamma correction as needed to
optimize screen contrast and color.
Video output
Decoded, scaled video is output through a digital video output
port in various YUV or RGB formats, including packed and planar,
gamma-compensated, or black-stretched.
VBI capture
The SAA7173 captures raw VBI samples to memory, making them
available to software components for decoding.The VBI sampling
rate can be adjusted as needed by the data slicing software.
Supported VBI formats include Closed Captioning,Teletext,WST,
NABST, CGMS, and WSS.