diff --git a/codec/decoder/plus/src/welsDecoderExt.cpp b/codec/decoder/plus/src/welsDecoderExt.cpp
index 902ac4a1..0d03db6d 100644
--- a/codec/decoder/plus/src/welsDecoderExt.cpp
+++ b/codec/decoder/plus/src/welsDecoderExt.cpp
@@ -110,23 +110,23 @@ CWelsDecoder::CWelsDecoder (void_t)
   iBufUsedSize += WelsSnprintf (chFileNameSize, iBufLeftSize, "size_0x%p_", (void_t*)this);
 
   iBufLeft -= iBufUsed;
-  if (iBufLeft > iBufUsed) {
+  if (iBufLeft > 0) {
     iBufUsed += WelsStrftime (&chFileName[iBufUsed], iBufLeft, "%y%m%d%H%M%S", &sCurTime);
     iBufLeft -= iBufUsed;
   }
 
   iBufLeftSize -= iBufUsedSize;
-  if (iBufLeftSize > iBufUsedSize) {
+  if (iBufLeftSize > 0) {
     iBufUsedSize += WelsStrftime (&chFileNameSize[iBufUsedSize], iBufLeftSize, "%y%m%d%H%M%S", &sCurTime);
     iBufLeftSize -= iBufUsedSize;
   }
 
-  if (iBufLeft > iBufUsed) {
+  if (iBufLeft > 0) {
     iBufUsed += WelsSnprintf (&chFileName[iBufUsed], iBufLeft, ".%03.3u.264", WelsGetMillsecond (&sCurTime));
     iBufLeft -= iBufUsed;
   }
 
-  if (iBufLeftSize > iBufUsedSize) {
+  if (iBufLeftSize > 0) {
     iBufUsedSize += WelsSnprintf (&chFileNameSize[iBufUsedSize], iBufLeftSize, ".%03.3u.len",
                                   WelsGetMillsecond (&sCurTime));
     iBufLeftSize -= iBufUsedSize;
diff --git a/codec/encoder/plus/src/welsEncoderExt.cpp b/codec/encoder/plus/src/welsEncoderExt.cpp
index 4e94dbf4..fe236c05 100644
--- a/codec/encoder/plus/src/welsEncoderExt.cpp
+++ b/codec/encoder/plus/src/welsEncoderExt.cpp
@@ -132,7 +132,7 @@ CWelsH264SVCEncoder::CWelsH264SVCEncoder()
 
 
   iBufferLeft -= iBufferUsed;
-  if (iBufferLeft > iBufferUsed) {
+  if (iBufferLeft > 0) {
 #if defined(_GNUC__)
     iBufferUsed += strftime (&strStreamFileName[iBufferUsed], iBufferLeft, "%y%m%d%H%M%S", tTimeNow);
 #else
@@ -150,7 +150,7 @@ CWelsH264SVCEncoder::CWelsH264SVCEncoder()
   }
 
   iBufferLeftSize -= iBufferUsedSize;
-  if (iBufferLeftSize > iBufferUsedSize) {
+  if (iBufferLeftSize > 0) {
 #if defined(_GNUC__)
     iBufferUsedSize += strftime (&strLenFileName[iBufferUsedSize], iBufferLeftSize, "%y%m%d%H%M%S", tTimeNow);
 #else
@@ -167,7 +167,7 @@ CWelsH264SVCEncoder::CWelsH264SVCEncoder()
     iBufferLeftSize -= iBufferUsedSize;
   }
 
-  if (iBufferLeft > iBufferUsed) {
+  if (iBufferLeft > 0) {
 #ifdef _WIN32
 #if defined(_MSC_VER)
 #if _MSC_VER>=1500
@@ -182,7 +182,7 @@ CWelsH264SVCEncoder::CWelsH264SVCEncoder()
     iBufferLeft -= iBufferUsed;
   }
 
-  if (iBufferLeftSize > iBufferUsedSize) {
+  if (iBufferLeftSize > 0) {
 #ifdef _WIN32
 #if defined(_MSC_VER)
 #if _MSC_VER>=1500