If you take the text I gave, save it as a json file and then import it it gives you what you want, a tiddler with the json data in the text field. The example you give would be like this:
[
{
"text": "{\n \"tiddler\": \"DVDForme103.Enchainement\",\n \"description\":\"Enchainement complet de la forme 103 par Maître Yang Jun (DVD)\",\n \"séquences\":\n [\n {\"description\":\"Partie 1\", \"type\": \"Déroulé\", \"départ\": 7},\n {\"description\":\"Partie 2\", \"type\": \"Déroulé\", \"départ\": 223},\n {\"description\":\"Partie 3\", \"type\": \"Déroulé\", \"départ\": 754}\n ],\n \"technique\":\n {\n \"source\":\"DVD\",\n \"durée\": 1489,\n \"largeur\": 640,\n \"hauteur\": 480,\n \"taille\": 14.67\n }\n}",
"title": "Change This Title",
"type": "application/json"
}
]
If you save that as a json file and import it than you will get a tiddler with your json data in the text field.
If it is going to be a tiddler than it has to have the tiddler form. Otherwise tiddlywiki can't do anything with it. When you import a json object into tiddlywiki it is parsed as a tiddler so it looks for the standard fields (title, text, etc.) so if you want to have something in the text field of a tiddler you have to create the json object you are importing in the form that tiddlywki can parse. So you would need to have at a minimum
[
{
"text": "some text here"
"title": "Change This Title",
"type": "application/json"
}
]
or tiddlywiki can't parse it. You could write your own importer, but that would probably be overkill. Replace the 'some text here' with the properly escaped text and it will import your tiddler the way you want. Perl would make it easy to take the fields you make in geany and do the proper escaping and put it into the correct format.