Linux: Failing to load 32bpp BMP previously exported from Aseprite.

[sammynilla]

Pixelorama version: v0.10.3

Issue description: I'm currently trying to load a bitmap file that was previously exported from Aseprite v1.2.40-dev that was built from source as I'm looking into alternative art programs, but I'm being greeted with error code 16. At first I thought that maybe I had accidentally exported my bitmap as a 16bpp image, which isn't supported via Godot's built-in asset pipeline, but I analyzed the image a few moments ago and it actually is 32bpp.

The exported bitmap will not load properly if you choose to create a new sprite with a background that is transparent, regardless of if you fill in the background afterwards or not.

Extra Notes: There seems to be different behaviors among different art programs.

• The bitmaps will load properly via Pixelorama if you do the same thing, but choose to start with the sprite filled with white or black.
• Both versions load into Aseprite properly, but the image will load in filled with a black color in place of a transparent background.
• Both versions also load into GIMP properly, but the image will load in with an actual transparent background.

Steps to reproduce:

• The image I'm failing to load is available to see here if Aseprite is unavailable to whomever may be trying to reproduce my bug.
• However, if you have Aseprite v1.2.40-dev available, just open it up, create a new sprite with RGBA and transparent background, and fill the background with your color of choosing before exporting it as a bitmap.
• Try to load it in Pixelorama.

[OverloadedOrama]

This should ideally be reported to Godot, as Pixelorama relies on Godot's code to load images. Although, in version 1.0, if you have FFMPEG installed and set up its path in the Preferences, the file seems to load, but the background is purple and not transparent.