IMBUF: Faster JPEG Thumbnails

Make preview thumbnails of JPEG files in less time and with less RAM.

See D14727 for more details.

Differential Revision: https://developer.blender.org/D14727

Reviewed by Brecht Van Lommel

1 files changed, 15 insertions, 0 deletions

diff --git a/source/blender/imbuf/intern/IMB_filetype.h b/source/blender/imbuf/intern/IMB_filetype.h
index 31f8b3a9505..bcca6f9fd85 100644
--- a/source/blender/imbuf/intern/IMB_filetype.h
+++ b/source/blender/imbuf/intern/IMB_filetype.h
@@ -36,6 +36,15 @@ typedef struct ImFileType {
                         char colorspace[IM_MAX_SPACE]);
   /** Load an image from a file. */
   struct ImBuf *(*load_filepath)(const char *filepath, int flags, char colorspace[IM_MAX_SPACE]);
+  /** Load/Create a thumbnail image from a filepath. `max_thumb_size` is maximum size of either
+   * dimension, so can return less on either or both. Should, if possible and performant, return
+   * dimensions of the full-size image in width_r & height_r. */
+  struct ImBuf *(*load_filepath_thumbnail)(const char *filepath,
+                                           const int flags,
+                                           const size_t max_thumb_size,
+                                           size_t *width_r,
+                                           size_t *height_r,
+                                           char colorspace[IM_MAX_SPACE]);
   /** Save to a file (or memory if #IB_mem is set in `flags` and the format supports it). */
   bool (*save)(struct ImBuf *ibuf, const char *filepath, int flags);
   void (*load_tile)(struct ImBuf *ibuf,
@@ -143,6 +152,12 @@ struct ImBuf *imb_load_jpeg(const unsigned char *buffer,
                             size_t size,
                             int flags,
                             char colorspace[IM_MAX_SPACE]);
+struct ImBuf *imb_thumbnail_jpeg(const char *filepath,
+                                 const int flags,
+                                 const size_t max_thumb_size,
+                                 size_t *width_r,
+                                 size_t *height_r,
+                                 char colorspace[IM_MAX_SPACE]);
 
 /** \} */