Expose builtin models

libvmaf/include/libvmaf/model.h

@@ -70,6 +70,20 @@ typedef struct VmafModelCollectionScore {
     } bootstrap;
 } VmafModelCollectionScore;
 
+typedef struct VmafModelDescriptor{
+    const char *version;
+} VmafModelDescriptor;
+
+/**
+ * Iterate through all built in vmaf models
+ * 
+ * @param prev previous model. NULL to get the first model
+ * 
+ * @return next model or NULL after the last model
+ * 
+*/
+const VmafModelDescriptor *vmaf_model_descriptor_next(const VmafModelDescriptor *prev);
+
 int vmaf_model_collection_load(VmafModel **model,
                                VmafModelCollection **model_collection,
                                VmafModelConfig *cfg,

libvmaf/src/model.c

@@ -13,12 +13,6 @@
 #include "read_json_model.h"
 #include "svm.h"
 
-typedef struct VmafBuiltInModel {
-    const char *version;
-    const char *data;
-    const int *data_len;
-} VmafBuiltInModel;
-
 #if VMAF_BUILT_IN_MODELS
 #if VMAF_FLOAT_FEATURES
 extern const char src_vmaf_float_v0_6_1neg_json;
@@ -42,6 +36,17 @@ extern const char src_vmaf_4k_v0_6_1neg_json;
 extern const int src_vmaf_4k_v0_6_1neg_json_len;
 #endif
 
+/**
+ * For the purposes of working with vmaf_model_descriptor_next,
+ * the version property of VmafBuiltInModel must be the first property
+ * declared on this struct
+*/
+typedef struct VmafBuiltInModel {
+    const char *version;
+    const char *data;
+    const int *data_len;
+} VmafBuiltInModel;
+
 static const VmafBuiltInModel built_in_models[] = {
 #if VMAF_BUILT_IN_MODELS
 #if VMAF_FLOAT_FEATURES
@@ -322,3 +327,15 @@ int vmaf_model_collection_feature_overload(VmafModel *model,
     return err;
 }
 
+const VmafModelDescriptor *vmaf_model_descriptor_next(const VmafModelDescriptor *prev){
+    // Cast *VmafModelDescriptor into *VmafBuiltInModel
+    VmafBuiltInModel *builtin = (VmafBuiltInModel*)prev;
+
+    if(!builtin)
+        return (VmafModelDescriptor*)&built_in_models[0];
+
+    if(builtin - built_in_models < BUILT_IN_MODEL_CNT)
+        return (VmafModelDescriptor*)(builtin + 1);
+
+    return NULL;
+}

libvmaf/src/model.h

@@ -83,6 +83,16 @@ typedef struct VmafModelCollection {
     const char *name;
 } VmafModelCollection;
 
+/**
+ * Iterate through all built in vmaf models
+ * 
+ * @param prev previous model. NULL to get the first model
+ * 
+ * @return next model or NULL after the last model
+ * 
+*/
+const VmafModelDescriptor *vmaf_model_descriptor_next(const VmafModelDescriptor *prev);
+
 char *vmaf_model_generate_name(VmafModelConfig *cfg);
 
 int vmaf_model_collection_append(VmafModelCollection **model_collection,

libvmaf/test/test_model.c

@@ -371,6 +371,29 @@ static char *test_model_set_flags()
     return NULL;
 }
 
+/**
+ * This test may fail if VmafBuiltInModel's memory layout has changed
+ *  (version MUST be the first defined property in the struct)
+ */
+char *test_model_descriptor_next()
+{
+    VmafModelDescriptor *next = NULL;
+    VmafModelConfig config = {.name = NULL, .flags = VMAF_MODEL_FLAGS_DEFAULT};
+    while (next = vmaf_model_descriptor_next(next))
+    {
+        VmafBuiltInModel *builtin = next;
+        mu_assert("Version field should match on both builtin and next", next->version == builtin->version);
+        VmafModel *model;
+        printf(next->version);
+        printf("\n");
+        int err = vmaf_model_load(&model, &config, next->version);
+
+        mu_assert("Model load should not return an error",err==0);
+        vmaf_model_destroy(model);
+    }
+    return NULL;
+}
+
 char *run_tests()
 {
     mu_run_test(test_json_model);
@@ -382,5 +405,6 @@ char *run_tests()
     mu_run_test(test_model_check_default_behavior_set_flags);
     mu_run_test(test_model_set_flags);
     mu_run_test(test_model_feature);
+    mu_run_test(test_model_descriptor_next);
     return NULL;
 }