Closed Captions

Closed Captions (part 2)

"Closed Caption and the THX label: Certain laserdiscs labelled THX (The "STAR WARS" set, among others), contain coding errors. Certain decoders allow, thanks to their internal functioning mode, to correct this in part by selecting the button "language 2" (they still only decode a "part" of the code, because in some places, the coding is so badly realised that decoding becomes virtually impossible).

Important: the fact that discs labelled THX have problems with Closed Caption has nothing to do with the THX label itself. It’s an unfortunate coincidence, as THX discs are strictly identical to all the others, with quality as a plus. Moreover, only one sole coding frequency exists for closed caption. This frequency (the 21st line in video), allows for the coding of two languages, probably English and Spanish, because they are primarily targeted at the American public. In any case, until now, in fact no discs appear to have been coded in two languages, which is why closed caption decoders don’t have a language 1 and 2 button.

Closed Caption and 16/9The closed caption text is normally carried at the bottom of the screen. It can, in some cases though, be situated at the top of the screen, for example during musical passages. It also sometimes follows the actor who is speaking. Closed Caption coding allows, during the coding, to place the text wherever the publisher wishes. The utilisation of a closed caption decoder on a 16/9 TV poses a real problem. In position EXTEND/WIDE, the sub title is either cut-off or totally hidden. This problem can however be resolved if you have a television that allows you to control the image in terms of its position from top to bottom. It suffices to move the image a little higher, at the extremity of the black line of the wide screen. The subtitles will then be sufficiently visible. This solution is only really practical in the case where the cinema format is 2.35. In the opposite case, the image will be somewhat cut-off at the top.

Closed Caption and French subtitling: Closed Caption was designed by Americans for Americans: it is thus logical that it be coded in English. It remains possible that some discs be coded in English and Spanish, given the large Spanish speaking population in the USA.

Players that transform the video signal: One of the strategies used by manufacturers so that NTSC may be visible on a Pal/Secam TV is Pal 60Hz. This process transforms part of the NTSC signal into Pal. Some closed caption decoders do not support this light decoding, and as a result, refuse to decode anything at all. If you have come across this problem, and your Closed Caption decoder refuses to display subtitles, you will have to: firstly, supply your decoder with a "pure" NTSC signal

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