SAA7135 Datasheet, PDF (3/6 Pages) NXP Semiconductors – Single-chip, analog TV video/stereo DECODER

audio loop back cable
antenna
or cable
HYBRID TV CAPTURE/PVR PCI CARD
ATSC/DVB/
TV TUNER & ^BS-Digital
INTERFACE
CHANNEL
DECODER
I2C
EEPROM
CVBS
S-Video
audio
audio
line-in
I2C TS
MPEG PS
SAA7135
ITU/VIP
I²S
PCI BUS
digital video, digital audio, raw VBI, digital TS
AGP
NORTH
BRIDGE
MEMORY
CPU
audio loop back cable
antenna
or cable
STANDALONE ANALOG TV GRAPHICS CARD
TV TUNER
CVBS
S-Video
audio
audio
line-in
SAA7135
ITU/VIP
I²C
AGP
NORTH
BRIDGE
PCI BUS
MEMORY
CPU
Typical SAA7135 configurations: a PCI add-in card for capture of live analog and digital TV video and audio (left), and a graphics card
for analog TV capture (right).
Scaling, matrix, clipping
The SAA7135 incorporates an adaptive filter and circuitry to
crop, scale, and reduce frame rate. It can peform horizontal or
vertical video down scaling or zooming to support playback win-
dows 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. A clipping unit allows defini-
tion of overlay rectangles (for Video for Windows (VfW) legacy
requirements) or assignment of alpha values to video pixels.
Output
Decoded, scaled video can be output in various YUV or RGB
formats, including packed and planar, gamma-compensated or
black-stretched.The video stream is transmitted through DMA
writes across the PCI bus or through a digital video output port
in standalone configurations.
Stereo decoding and audio processing
Capture and decoding
The SAA7135 handles capture and on-chip decoding of stereo
formats used in analog TV including: BTSC with dbx noise reduc-
tion and SAP (North America), EIAJ (Japan), and NICAM and A2/
Dual-FM (Europe). After capture from the TV tuner through a
Sound Intermediate Frequency (SIF) port, the TV sound signal is
digitized and FM or AM demodulated.The audio standard is auto-
matically detected, the pilot tone is investigated (mono, stereo,
dual), and the signal is decoded.
Two 16-bit audio ADCs support capture of audio signals from
nonstandard sources such as video cameras,VCRs, and AM (mono)
or FM (stereo) radio through two stereo line-in inputs. The
SAA7135’s analog audio pass-through enables an incoming audio
signal to be rerouted without processing through an external
loop-back cable to a sound card. A field-locked audio clock sam-
ples a constant number of audio clocks per video field,
guaranteeing synchronization between audio and video streams.
Advanced audio feature processing
The SAA7135’s advanced, on-chip audio-feature processing
improves user control and perceived audio quality. A Dolby Pro
Logic decoder ‘unfolds’ four-channel Dolby Surround audio when
it is present in VHS movies and TV broadcasts. A Virtual Dolby