avfilter/dnn: Use dnn_backend_info_list to search for dnn module

Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>
Reviewed-by: Wenbin Chen <wenbin.chen@intel.com>
Reviewed-by: Guo Yejun <yejun.guo@intel.com>

libavfilter/dnn/dnn_backend_openvino.c

@@ -1622,6 +1622,7 @@ static int dnn_flush_ov(const DNNModel *model)
 
 const DNNModule ff_dnn_backend_openvino = {
     .clazz          = DNN_DEFINE_CLASS(dnn_openvino),
+    .type           = DNN_OV,
     .load_model     = dnn_load_model_ov,
     .execute_model  = dnn_execute_model_ov,
     .get_result     = dnn_get_result_ov,

libavfilter/dnn/dnn_backend_tf.c

@@ -893,6 +893,7 @@ static int dnn_flush_tf(const DNNModel *model)
 
 const DNNModule ff_dnn_backend_tf = {
     .clazz          = DNN_DEFINE_CLASS(dnn_tensorflow),
+    .type           = DNN_TF,
     .load_model     = dnn_load_model_tf,
     .execute_model  = dnn_execute_model_tf,
     .get_result     = dnn_get_result_tf,

libavfilter/dnn/dnn_backend_torch.cpp

@@ -569,6 +569,7 @@ static int dnn_flush_th(const DNNModel *model)
 
 extern const DNNModule ff_dnn_backend_torch = {
     .clazz          = DNN_DEFINE_CLASS(dnn_th),
+    .type           = DNN_TH,
     .load_model     = dnn_load_model_th,
     .execute_model  = dnn_execute_model_th,
     .get_result     = dnn_get_result_th,

libavfilter/dnn/dnn_interface.c

@@ -81,25 +81,15 @@ static const DnnBackendInfo dnn_backend_info_list[] = {
 
 const DNNModule *ff_get_dnn_module(DNNBackendType backend_type, void *log_ctx)
 {
-    switch(backend_type){
-    #if (CONFIG_LIBTENSORFLOW == 1)
-    case DNN_TF:
-        return &ff_dnn_backend_tf;
-    #endif
-    #if (CONFIG_LIBOPENVINO == 1)
-    case DNN_OV:
-        return &ff_dnn_backend_openvino;
-    #endif
-    #if (CONFIG_LIBTORCH == 1)
-    case DNN_TH:
-        return &ff_dnn_backend_torch;
-    #endif
-    default:
-        av_log(log_ctx, AV_LOG_ERROR,
-                "Module backend_type %d is not supported or enabled.\n",
-                backend_type);
-        return NULL;
+    for (int i = 1; i < FF_ARRAY_ELEMS(dnn_backend_info_list); i++) {
+        if (dnn_backend_info_list[i].module->type == backend_type)
+            return dnn_backend_info_list[i].module;
     }
+
+    av_log(log_ctx, AV_LOG_ERROR,
+            "Module backend_type %d is not supported or enabled.\n",
+            backend_type);
+    return NULL;
 }
 
 void ff_dnn_init_child_class(DnnContext *ctx)

libavfilter/dnn_interface.h

@@ -172,6 +172,7 @@ typedef struct DnnContext {
 // Stores pointers to functions for loading, executing, freeing DNN models for one of the backends.
 struct DNNModule {
     const AVClass clazz;
+    DNNBackendType type;
     // Loads model and parameters from given file. Returns NULL if it is not possible.
     DNNModel *(*load_model)(DnnContext *ctx, DNNFunctionType func_type, AVFilterContext *filter_ctx);
     // Executes model with specified input and output. Returns the error code otherwise.