Difference between revisions of "Teletext"
From Fixme.ch
(→Ressources) |
|||
| Line 33: | Line 33: | ||
===Repo pour les pages FIXME=== | ===Repo pour les pages FIXME=== | ||
* https://git.fixme.ch/FIXME/teletext | * https://git.fixme.ch/FIXME/teletext | ||
| + | |||
| + | ===Code for image conversion=== | ||
| + | |||
| + | Done by Nico D. in Perl. | ||
| + | |||
| + | Image must first be processed in Gimp to resize it to 80 pixel width, colour converted to 1 bit black&white, floyd-steinberg. | ||
| + | |||
| + | #!/usr/bin/perl | ||
| + | |||
| + | use GD; | ||
| + | |||
| + | open(F,">/tmp/test3.tti"); | ||
| + | |||
| + | open (IM,"mc80.png") || die; | ||
| + | $im = newFromPng GD::Image('IM'); | ||
| + | close IM; | ||
| + | |||
| + | print F "DE,Read back page40600 | ||
| + | PN,40600 | ||
| + | CT,15 | ||
| + | SC,0001 | ||
| + | PS,8040 | ||
| + | MS,40600 | ||
| + | "; | ||
| + | |||
| + | $xbase = 0; | ||
| + | $ybase = 0; | ||
| + | |||
| + | $y = $ybase; | ||
| + | |||
| + | for($i=0;$i<25;$i++) { | ||
| + | print F "OL,$i,".chr(0x1b).chr(0x57); | ||
| + | $x = $xbase; | ||
| + | for($c=0; $c<40; $c++) { | ||
| + | $t = | ||
| + | $im->getPixel($x, $y) + ($im->getPixel($x + 1, $y ) << 1) + | ||
| + | ($im->getPixel($x, $y + 1) << 2 ) + ($im->getPixel($x + 1, $y + 1) << 3) + | ||
| + | ($im->getPixel($x, $y + 2) << 4 ) + ($im->getPixel($x + 1, $y + 2) << 5); | ||
| + | |||
| + | $t^=63; | ||
| + | |||
| + | $t+=32; | ||
| + | |||
| + | if($t>=64) { $t+=32; } | ||
| + | print F chr($t); | ||
| + | $x += 2; | ||
| + | } | ||
| + | $y += 3; | ||
| + | |||
| + | print F "\n"; | ||
| + | } | ||
| + | print F "FL,407,408,410,405,00F,400"; | ||
Revision as of 17:49, 7 March 2020
Contents
Workshop Teletext
Talk et Workshop 6 Mars 2020.
Workgroup
- Faire des pages, essayer de créer un service (Télétexte Fixme?) => etc
- Brainstorm contenu et intérêt d’un système minimaliste. Quel contenu pour quelle utilisations ? Ecrire idées/concept
- Transmission , radio ou autre. Essayer de transmettre une page par un moyen autre. => MPB, Francois, Mathias
- Brainstorm transmission, réfléchir à des moyens de transmission et écrire idées/concept =>Sasha
- Recevoir/afficher. Réfléchir à des moyens minimaux d’affichage (badge CCC, vintage computer..) et tenter de l’afficher
- Brainstorm Concept crypto à réfléchir ou élaborer. Ecrire idées/concept
Ressources
Editeurs:
Generateur teletext:
Specification Teletext:
Repo pages Teefax
Specification format fichier TTI (editeur)
Repo pour les pages FIXME
Code for image conversion
Done by Nico D. in Perl.
Image must first be processed in Gimp to resize it to 80 pixel width, colour converted to 1 bit black&white, floyd-steinberg.
#!/usr/bin/perl
use GD;
open(F,">/tmp/test3.tti");
open (IM,"mc80.png") || die;
$im = newFromPng GD::Image('IM');
close IM;
print F "DE,Read back page40600
PN,40600
CT,15
SC,0001
PS,8040
MS,40600
";
$xbase = 0;
$ybase = 0;
$y = $ybase;
for($i=0;$i<25;$i++) {
print F "OL,$i,".chr(0x1b).chr(0x57);
$x = $xbase;
for($c=0; $c<40; $c++) {
$t =
$im->getPixel($x, $y) + ($im->getPixel($x + 1, $y ) << 1) +
($im->getPixel($x, $y + 1) << 2 ) + ($im->getPixel($x + 1, $y + 1) << 3) +
($im->getPixel($x, $y + 2) << 4 ) + ($im->getPixel($x + 1, $y + 2) << 5);
$t^=63;
$t+=32;
if($t>=64) { $t+=32; }
print F chr($t);
$x += 2;
}
$y += 3;
print F "\n";
}
print F "FL,407,408,410,405,00F,400";
