[Thunar-dev] A Standard for Thumbnailers

[Benedikt Meurer]

Erlend Davidson wrote:
>> Checking my own source again... you should be able to store the
>> thumbnail as JPEG. thunar_vfs_thumb_factory_generate_thumbnail() will
>> also accept JPEGs and convert them to PNGs internally.
> Ok, I've tested this - it doesn't work.  Thinking about it this makes sense:
> thunar invokes the raw-thumbnailer, saying "produce a thumbnail of ifile 
> called ofile".  ofile is a png image, or at least an image with a png 
> extension.  But if the thumbnailer gives a .png file in which the format 
> is actually jpg/ppm then pixbuf will get confused. 

GdkPixbuf does content sniffing, so it'll properly detect the JPEG/PNM
content. Also note that the extension of the ofile is not .png.

> Also, the 
> raw-thumbnailer script won't get the chance to resize the image - so 
> it'll be on the order 3000x2000 pixels!

Uhm, that's HUGE. Better scale that down in a separate process to avoid
growing Thunar's heap.

Benedikt