diff --git a/FFNvDecoder/FFNvDecoder.cpp b/FFNvDecoder/FFNvDecoder.cpp
index 2fa20b6..b17f3bd 100644
--- a/FFNvDecoder/FFNvDecoder.cpp
+++ b/FFNvDecoder/FFNvDecoder.cpp
@@ -59,14 +59,6 @@ bool FFNvDecoder::init(FFDecConfig& cfg)
 {
 	m_cfg = cfg;
 
-	fstream infile(cfg.uri);
-	if (infile.is_open()){
-		m_bReal = false;
-		infile.close();
-	}else {
-		m_bReal = true;
-	}
-
 	return init(cfg.uri.c_str(), cfg.gpuid.c_str(),cfg.force_tcp);
 }
 
@@ -90,6 +82,12 @@ bool FFNvDecoder::init(const char* uri, const char* gpuid, bool force_tcp)
 		return false;
 	}
 
+	if (fmt_ctx->iformat && fmt_ctx->iformat->extensions) {
+		m_bReal = false;
+	} else {
+		m_bReal = true;
+	}
+	
 	// 查找流信息
 	if (avformat_find_stream_info(fmt_ctx, nullptr) < 0) {
 		cout << "Cannot find input stream information";