Serial Digital Line 23 - Wide Screen Decoder
 Supports AFD
 GPI outputs
 LCD Display
 RS232 /422

In a broadcast system which is using both standard 4:3 and wide screen (16:9) format pictures it is useful to label the
video signal with aspect ratio information. This allows equipment in the transmission chain to know what the picture
format is. There are currently two different signals used by UK broadcasters; Video Index (line 11) and Wide Screen
Signalling (line 23). We supply Generators and Decoders for both types of signalling. This datasheet covers only the
line 23 decoder.

Line 23 data:
The waveform used is of the same specification as PAL Plus but the 14 bits of data are interpreted differently. They are
used to convey the source aspect ratio (4:3 or 16:9) and the active format descriptor (AFD) that is required for digital
terrestrial systems. Contact Microvideo for the latest specification on the AFD data format. The advantage of using the
line 23 waveform is that it will pass through an analogue system and be decoded either in the analogue or digital
domain. Video Index may only be used in the digital domain. The Microvideo WSS Decoder is a digital decoder for line
23 carried in SDV.

The line 23 data format allows signalling of the source (coded image) aspect ratio and the Active Format Descriptor
(AFD). The coding for the AFD is given as -

0 0 0 Active region same as coded frame (source material)
0 0 1 4:3
0 1 0 16:9
0 1 1 14:9
1 0 0 not used - reserved for future use
1 0 1 4:3 with shoot and protect 14:9 centre
1 1 0 16 : 9 with shoot and protect 14:9 centre
1 1 1 not used - reserved for future use

Video Input : SDV(270Mb/s) as per SMPTE259M

Video Output : 1 x SDV(270Mb/s) relocked outputs - exact copy of input
power-fail relay protected

Data Interface : Coded (source) image and AFD is displayed on an LCD and output on 5 x GPI's.
The GPIs are TTL level outputs, active low, on 9 way D type.
It is proposed that they are configured -
C1 Valid Data (1) or No Data Present (0)
C2 Aspect ratio of source material (16:9 or 4:3)
C3,C4,C5 - The AFD information inserted - (using coding given above)
RS232 and RS422 interfaces. Protocol is defined by Microvideo.

Physical The product will be supplied in 1U rack mounting frame with integral psu.

Product Code WSS - DEC 1U rack mounting unit with GPI and RS232/422 interface .