avfilter/dnn: add log context to ff_get_dnn_module

Print backend type when failed.
Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>

libavfilter/dnn/dnn_interface.c

@@ -29,7 +29,7 @@
 extern const DNNModule ff_dnn_backend_openvino;
 extern const DNNModule ff_dnn_backend_tf;
 
-const DNNModule *ff_get_dnn_module(DNNBackendType backend_type)
+const DNNModule *ff_get_dnn_module(DNNBackendType backend_type, void *log_ctx)
 {
     switch(backend_type){
     #if (CONFIG_LIBTENSORFLOW == 1)
@@ -41,7 +41,9 @@ const DNNModule *ff_get_dnn_module(DNNBackendType backend_type)
         return &ff_dnn_backend_openvino;
     #endif
     default:
-        av_log(NULL, AV_LOG_ERROR, "Module backend_type is not supported or enabled.\n");
+        av_log(log_ctx, AV_LOG_ERROR,
+                "Module backend_type %d is not supported or enabled.\n",
+                backend_type);
         return NULL;
     }
 }

libavfilter/dnn_filter_common.c

@@ -68,7 +68,7 @@ int ff_dnn_init(DnnContext *ctx, DNNFunctionType func_type, AVFilterContext *fil
         return AVERROR(EINVAL);
     }
 
-    ctx->dnn_module = ff_get_dnn_module(ctx->backend_type);
+    ctx->dnn_module = ff_get_dnn_module(ctx->backend_type, filter_ctx);
     if (!ctx->dnn_module) {
         av_log(filter_ctx, AV_LOG_ERROR, "could not create DNN module for requested backend\n");
         return AVERROR(ENOMEM);

libavfilter/dnn_interface.h

@@ -123,6 +123,6 @@ typedef struct DNNModule{
 } DNNModule;
 
 // Initializes DNNModule depending on chosen backend.
-const DNNModule *ff_get_dnn_module(DNNBackendType backend_type);
+const DNNModule *ff_get_dnn_module(DNNBackendType backend_type, void *log_ctx);
 
 #endif