nsgifload: choose tile-height based on page height (#2996)

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Sergey Alexandrovich 2022-09-09 00:05:42 +06:00 committed by GitHub
parent 1bd618546b
commit ce31c04cd2
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1 changed files with 21 additions and 1 deletions

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@ -487,6 +487,26 @@ vips_foreign_load_nsgif_generate( VipsRegion *or,
return( 0 );
}
int
vips_foreign_load_nsgif_tile_height(VipsForeignLoadNsgif *gif) {
int i;
int height = gif->info->height;
// First, check the perfect size
if (height % 16 == 0)
return 16;
// Next, check larger and smaller sizes
for (i = 1; i < 16; i++) {
if (height % (16 + i) == 0)
return (16 + i);
if (height % (16 - i) == 0)
return (16 - i);
}
return 1;
}
static int
vips_foreign_load_nsgif_load( VipsForeignLoad *load )
{
@ -507,7 +527,7 @@ vips_foreign_load_nsgif_load( VipsForeignLoad *load )
if( vips_image_generate( t[0],
NULL, vips_foreign_load_nsgif_generate, NULL, gif, NULL ) ||
vips_sequential( t[0], &t[1],
"tile_height", VIPS__FATSTRIP_HEIGHT,
"tile_height", vips_foreign_load_nsgif_tile_height(gif),
NULL ) ||
vips_image_write( t[1], load->real ) )
return( -1 );