At least I think they are Hungarian??
http://vmek.niif.hu/01800/01885/html/index921.html
http://mek.oszk.hu/01900/01918/html/index1278.html
http://mek.oszk.hu/01900/01918/html/index969.html
http://www.sigismundus.hu/guide/show.php?l=hu&p=4_121a
http://www.sigismundus.hu/guide/pictures/4_5a.jpg
http://garfield.axio.hu/itemimages/big/_45/05_nov/078.jpg
http://garfield.axio.hu/itemimages/big/_45/05_nov/079.jpg
http://garfield.axio.hu/itemimages/big/_45/05_nov/080.jpg
http://garfield.axio.hu/itemimages/big/_45/05_nov/083.jpg
Here is some info about one of these grants:
Paris, 26 March 1416; Bratislava, Slovenský národný archív, Archív rodu Zay z Uhrovca
During his stay in Paris, Sigismund presented this letter patent to Palatine Garai, his brother-in-law and member of his retinue, renewing and extending the family’s old armorial bearings. The document mentions an adjunct to the grant, the conferment of arms to Garai by Charles VI of France for his use in that country. No other such double grant involving Sigismund is known of, and the exceptional status of the affair is underlined by fine execution of the two letters patent and the striking resemblance between them. The placing of the armorial bearings in the centre is a characteristic of imperial letters patent, and both have the doubled Garai arms, with the intertwined emblems of the Order of the Dragon and the Order of the Scarf between them. The two documents may have been the work of the same artist.
http://www.sigismundus.hu/guide/pictures/4_121a-d1.jpg