Merge pull request #20647 from andriiryzhkov/ort_gpu

[AI] ORT library path preference and GPU acceleration UI

Author: TurboGit

data/darktableconfig.xml.in

@@ -396,6 +396,13 @@
     <shortdescription>AI execution provider</shortdescription>
     <longdescription>select the hardware acceleration provider for AI inference. 'auto' will automatically detect the best available option for your system.</longdescription>
   </dtconfig>
+  <dtconfig>
+    <name>plugins/ai/ort_library_path</name>
+    <type>string</type>
+    <default></default>
+    <shortdescription>custom ONNX Runtime library path</shortdescription>
+    <longdescription>path to a custom ONNX Runtime shared library with GPU support (e.g. CUDA, MIGraphX, OpenVINO). when empty, darktable uses its bundled CPU-only library. set this to enable GPU acceleration without rebuilding.</longdescription>
+  </dtconfig>
   <dtconfig>
     <name>plugins/ai/repository</name>
     <type>string</type>

src/ai/CMakeLists.txt

@@ -40,9 +40,13 @@ if(UNIX AND NOT APPLE)
   # before darktable has a chance to check the AI-enabled preference.
   # Also suppresses harmless "already registered" ONNX schema warnings
   # from system packages that link against libonnx.
+  # Use just the filename (not the full build-tree path) so g_module_open
+  # resolves it via LD_LIBRARY_PATH / system linker search. This is required
+  # for AppImage where the build-tree path does not exist at runtime.
+  get_filename_component(_ORT_LIB_NAME "${ONNXRuntime_LIBRARIES}" NAME)
   target_compile_definitions(darktable_ai PRIVATE
     ORT_LAZY_LOAD=1
-    ORT_LIBRARY_PATH="${ONNXRuntime_LIBRARIES}")
+    ORT_LIBRARY_PATH="${_ORT_LIB_NAME}")
   target_include_directories(darktable_ai PRIVATE ${ONNXRuntime_INCLUDE_DIRS})
 else()
   target_link_libraries(darktable_ai PUBLIC onnxruntime::onnxruntime)

src/ai/backend.h

@@ -19,6 +19,7 @@
 #pragma once
 
 #include <stdint.h>
+#include <glib.h>
 
 /**
  * @brief AI Execution Provider
@@ -63,6 +64,31 @@ dt_ai_provider_t dt_ai_provider_from_string(const char *str);
  *  @return 1 if available, 0 if not. */
 int dt_ai_probe_provider(dt_ai_provider_t provider);
 
+/** Probe a shared library to check if it's a valid ONNX Runtime build.
+ *  @return version string (caller must g_free) or NULL on failure. */
+char *dt_ai_ort_probe_library(const char *path);
+
+/** Probe a library and return version + supported execution providers.
+ *  @param out_version version string (caller must g_free), may be NULL
+ *  @param out_eps comma-separated EP names (caller must g_free), may be NULL
+ *  @return 1 if valid ORT library, 0 otherwise */
+int dt_ai_ort_probe_library_full(const char *path, char **out_version, char **out_eps);
+
+/** Result from dt_ai_ort_find_libraries(). Caller owns all strings. */
+typedef struct dt_ai_ort_found_t
+{
+  char *path;     // full path to the library
+  char *version;  // ORT version string
+  char *eps;      // comma-separated execution provider names
+} dt_ai_ort_found_t;
+
+/** Scan system and user-space paths for valid ORT libraries.
+ *  @return GList of dt_ai_ort_found_t (caller must free with dt_ai_ort_found_free) */
+GList *dt_ai_ort_find_libraries(void);
+
+/** Free a dt_ai_ort_found_t */
+void dt_ai_ort_found_free(dt_ai_ort_found_t *f);
+
 /**
  * @brief Graph Optimization Level
  *