Files
test/source/blender/imbuf
Aras Pranckevicius f3ce0645e4 Color management: multi-thread IMB_colormanagement_transform_from_byte_threaded simple case
This function is only used in Sequencer code to convert source byte images
into float images. For a "simple case" where there is no color space
conversion needed, it was doing that on a single thread, in two passes over
the image (first byte -> float conversion, then alpha premultiply).

VSE 4K resolution playback, with two image strips where one of them has
"convert to float" option, on Windows / Ryzen 5950X:

- Overall playback FPS: 3.40 -> 4.03. Still very slow, and a lot of time
  is spent in allocating, clearing and deleting various temp images, as
  well as final color conversion for display.
- `seq_imbuf_to_sequencer_space` part: 217.9ms -> 86.6ms. Most of
  remaining cost is just in just memory allocation+clear, which is why
  it's not drastically faster due to threading.

Pull Request: https://projects.blender.org/blender/blender/pulls/115628
2023-12-01 16:18:47 +01:00
..

The following 4 steps to adding a new image format to blender, its
probably easiest to look at the png code for a clean clear example,
animation formats are a bit more complicated but very similar:

Step 1:
create a new file named after the format for example lets say we were
creating an openexr read/writer  use openexr.c
It should contain functions to match the following prototypes:

struct ImBuf *imb_loadopenexr(unsigned char *mem,int size,int flags);
/* Use one of the following depending on what's easier for your file format */
short imb_saveopenexr(struct ImBuf *ibuf, FILE myfile, int flags);
short imb_saveopenexr(struct ImBuf *ibuf, char *myfile, int flags);

/* Used to test if its the correct format
int IMB_is_openexr(void *buf);

Step 2:
Add your hooks to read and write the image format these go in
	writeimage.c and readimage.c  just look at how the others are done

Step 3:
Add in IS_openexr to blender/source/blender/imbuf/IMB_imbuf_types.h
Add in R_openexr to source/blender/makesdna/DNA_scene_types.h

Step 4:
Add your hooks to the gui.
source/blender/src/buttons_scene.c
source/blender/src/toets.c
source/blender/src/writeimage.c

Step 5:
edit the following files:
blender/source/blender/imbuf/intern/util.c
blender/source/blender/src/filesel.c
blender/source/blender/src/screendump.c
and add your extension so that your format gets recognized in the thumbnails.

Step 6:
Alter the build process:
For cmake you need to edit blender/source/blender/imbuf/CMakeLists.txt
and add in your additional files to source_files.
If you have any external library info you will also need to add that
to the various build processes.

Step 7:
Its also good to add your image format to:
makepicstring in blender/source/blender/blenkernel/intern/image.c