gtk - GdkPixbuf can be created with `new_from_data` and `new_from_stream`. Why doesn't the latter require the resolution? -

i trying understand basics behind pixbuf , factory methods new_from_data , new_from_stream.

new_from_data requires string of bytes containing image data, , other information such bits per sample, , height of image.

what don't understand why new_from_stream not require additional image information. then, how can pixbuf know how render image new_from_stream not provide additional information other gio.inputstream ?

new_from_stream() expects stream of supported image file, equivalent new_from_file(). image formats contain metadata height , width.

new_from_data() on other hand expects pixel buffer, array of pixels without metadata.