In
televisionTelevision is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...
technology,
widescreen signaling (
WSS) is a
digitalA digital system is a data technology that uses discrete values. By contrast, non-digital systems use a continuous range of values to represent information...
stream embedded in the TV signal describing qualities of the broadcast, in particular the intended
aspect ratioThe aspect ratio of an image is the ratio of the width of the image to its height, expressed as two numbers separated by a colon. That is, for an x:y aspect ratio, no matter how big or small the image is, if the width is divided into x units of equal length and the height is measured using this...
of the image. This can be used by a
widescreenWidescreen images are a variety of aspect ratios used in film, television and computer screens. In film, a widescreen film is any film image with a width-to-height aspect ratio greater than the standard 1.37:1 Academy aspect ratio provided by 35mm film....
TVTelevision is a telecommunication medium for transmitting and receiving moving images that can be monochrome or colored, with accompanying sound...
to switch to the correct display mode.
The signal is placed in line 23 (PAL) and lines 20/283 (PAL-M and NTSC) and has 14 bits of information indicating:
B00 to B03 - 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 |
B04 to B07 - 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 |
B08 to B10 - 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 |
B11 to B13 - Others
| 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 |
External links
The source of this article is
wikipedia, the free encyclopedia. The text of this article is licensed under the
GFDL.
