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.
Contents
-
PAL and SECAM Systems 1
-
Group 1 (Aspect Ratio) 1.1
-
Group 2 (Enhanced Services) 1.2
-
Group 3 (Subtitles) 1.3
-
Group 4 (Other) 1.4
-
NTSC Systems 2
-
Word 0 2.1
-
Word 1 2.2
-
Word 2 2.3
-
See also 3
-
References 4
-
External links 5
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.[1]
Group 1 (Aspect Ratio)
|
b00
|
b01
|
b02
|
b03
|
Aspect ratio
|
Picture placement
|
Active lines
|
|
0
|
0
|
0
|
1
|
4:3
|
Full
|
576
|
|
1
|
0
|
0
|
0
|
14:9
|
Letterbox centre
|
504
|
|
0
|
1
|
0
|
0
|
14:9
|
Letterbox top
|
504
|
|
1
|
1
|
0
|
1
|
16:9
|
Letterbox centre
|
432
|
|
0
|
0
|
1
|
0
|
16:9
|
Letterbox top
|
432
|
|
1
|
0
|
1
|
1
|
>16:9
|
Letterbox deeper than 16:9
|
<432
|
|
0
|
1
|
1
|
1
|
14:9
|
Full-height 4:3, framed to be "14:9-safe"
|
576
|
|
1
|
1
|
1
|
0
|
16:9
|
Full-height 16:9 (anamorphic)
|
576
|
Group 2 (Enhanced Services)
|
b04
|
Mode
|
|
0
|
Camera Mode
|
|
1
|
Movie Mode
|
|
b05
|
Mode
|
|
0
|
PAL Standard
|
|
1
|
Colour Plus
|
|
b06
|
Mode
|
|
0
|
No Vertical helper
|
|
1
|
Vertical helper present
|
Group 3 (Subtitles)
|
b08
|
Mode
|
|
0
|
no subtitles
|
|
1
|
Teletext subtitles
|
|
b09
|
b10
|
Mode
|
|
0
|
0
|
No subtitles
|
|
1
|
0
|
Subtitles inside active image
|
|
0
|
1
|
Subtitles outside active image
|
|
1
|
1
|
Reserved
|
Group 4 (Other)
|
b11
|
Mode
|
|
0
|
No surround sound information
|
|
1
|
Surround sound mode
|
|
b12
|
Mode
|
|
0
|
No copyright asserted or status unknown
|
|
1
|
Copyright asserted
|
|
b13
|
Mode
|
|
0
|
Copying not restricted
|
|
1
|
Copying restricted
|
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
|
b0
|
Aspect Ratio
|
|
0
|
4:3
|
|
1
|
16:9
|
|
b1
|
Mode
|
|
0
|
Normal
|
|
1
|
Letterbox
|
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
-
^ http://www.divitec.ses/default/files/microvideo_wss-dec.pdf
-
ETSI EN 300 294 "Television Systems: 625-Line Television Wide Screen Signaling (WSS)"
External links
-
PDF of WSS standard
-
PDF of WSS in 625 lines and 525 lines standard
|
|
|
|
|
|
Television
|
|
|
|
|
|
|
|
|
|
|
|
625 lines
|
|
|
|
|
|
|
|
|
|
Hidden signals
|
|
|
|
|
Historical
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
This article was sourced from Creative Commons Attribution-ShareAlike License; additional terms may apply. World Heritage Encyclopedia content is assembled from numerous content providers, Open Access Publishing, and in compliance with The Fair Access to Science and Technology Research Act (FASTR), Wikimedia Foundation, Inc., Public Library of Science, The Encyclopedia of Life, Open Book Publishers (OBP), PubMed, U.S. National Library of Medicine, National Center for Biotechnology Information, U.S. National Library of Medicine, National Institutes of Health (NIH), U.S. Department of Health & Human Services, and USA.gov, which sources content from all federal, state, local, tribal, and territorial government publication portals (.gov, .mil, .edu). Funding for USA.gov and content contributors is made possible from the U.S. Congress, E-Government Act of 2002.
Crowd sourced content that is contributed to World Heritage Encyclopedia is peer reviewed and edited by our editorial staff to ensure quality scholarly research articles.
By using this site, you agree to the Terms of Use and Privacy Policy. World Heritage Encyclopedia™ is a registered trademark of the World Public Library Association, a non-profit organization.