La réponse ci-dessus ne fonctionnera pas pour moi, donc j'ajouter ici ma solution - de http://www.tcpdf.org/examples/example_060.phps, changement urx, Ury pour votre but
// set page format (read source code documentation for further information)
// MediaBox - width = urx - llx 210 (mm), height = ury - lly = 297 (mm) this is A4
$page_format = array(
'MediaBox' => array ('llx' => 0, 'lly' => 0, 'urx' => 210, 'ury' => 297),
//'CropBox' => array ('llx' => 0, 'lly' => 0, 'urx' => 210, 'ury' => 297),
//'BleedBox' => array ('llx' => 5, 'lly' => 5, 'urx' => 205, 'ury' => 292),
//'TrimBox' => array ('llx' => 10, 'lly' => 10, 'urx' => 200, 'ury' => 287),
//'ArtBox' => array ('llx' => 15, 'lly' => 15, 'urx' => 195, 'ury' => 282),
'Dur' => 3,
'trans' => array(
'D' => 1.5,
'S' => 'Split',
'Dm' => 'V',
'M' => 'O'
),
'Rotate' => 90,
'PZ' => 1,
);
// Check the example n. 29 for viewer preferences
// add first page ---
$pdf->AddPage('P', $page_format, false, false);
Merci! M'a beaucoup aidé! – Refilon