Widescreen signaling

In television technology, widescreen signaling (WSS) is a digital stream embedded in the TV signal describing qualities of the broadcast, in particular the intended aspect ratio of the image. This can be used by a widescreen TV or other device to switch to the correct display mode.

PAL and SECAM Systems

For 625 scan line systems (PAL and SECAM), the signal is placed in line 23. It begins with a run-in code and start code followed by 14 bits of information.

Group 1 (Aspect Ratio)

Group 2 (Enhanced Services)

Group 3 (Subtitles)

Group 4 (Other)

NTSC Systems

525 scan line systems (PAL-M and NTSC) put the WSS data in lines 20 and 283. A start code consisting of the bits "10" is used, followed by 14 bits of information.

Word 0

b2-b5 all have the value "0".

Word 1

b6-b9 are reserved and all have the value "0".

Word 2

b10-b13 are reserved and all have the value "0".

See also

References