diff --git a/src/asfvideo.cpp b/src/asfvideo.cpp
index 9151b50d..df553524 100644
--- a/src/asfvideo.cpp
+++ b/src/asfvideo.cpp
@@ -217,7 +217,7 @@ void AsfVideo::readMetadata() {
 }  // AsfVideo::readMetadata
 
 AsfVideo::HeaderReader::HeaderReader(BasicIo::UniquePtr& io) : IdBuf_(GUID) {
-  if (io->size() >= io->tell() + QWORD + QWORD) {
+  if (io->size() >= io->tell() + GUID + QWORD) {
     IdBuf_ = io->read(GUID);
 
     size_ = readQWORDTag(io);
diff --git a/src/helper_functions.cpp b/src/helper_functions.cpp
index e33031b1..267b4b30 100644
--- a/src/helper_functions.cpp
+++ b/src/helper_functions.cpp
@@ -55,13 +55,13 @@ uint16_t readWORDTag(BasicIo::UniquePtr& io) {
   return FieldBuf.read_uint16(0, littleEndian);
 }
 
-std::string readStringWcharTag(BasicIo::UniquePtr& io, uint16_t length) {
+std::string readStringWcharTag(BasicIo::UniquePtr& io, size_t length) {
   Internal::enforce(length <= io->size() - io->tell(), Exiv2::ErrorCode::kerCorruptedMetadata);
   DataBuf FieldBuf = io->read(length);
   return toString16(FieldBuf);
 }
 
-std::string readStringTag(BasicIo::UniquePtr& io, uint16_t length) {
+std::string readStringTag(BasicIo::UniquePtr& io, size_t length) {
   Internal::enforce(length <= io->size() - io->tell(), Exiv2::ErrorCode::kerCorruptedMetadata);
   DataBuf FieldBuf = io->read(length);
   return Exiv2::toString(FieldBuf.data());
diff --git a/src/helper_functions.hpp b/src/helper_functions.hpp
index 5eb83054..f323977b 100644
--- a/src/helper_functions.hpp
+++ b/src/helper_functions.hpp
@@ -54,9 +54,9 @@ std::string toString16(Exiv2::DataBuf& buf);
 
 [[nodiscard]] uint16_t readWORDTag(Exiv2::BasicIo::UniquePtr& io);
 
-[[nodiscard]] std::string readStringWcharTag(Exiv2::BasicIo::UniquePtr& io, uint16_t length);
+[[nodiscard]] std::string readStringWcharTag(Exiv2::BasicIo::UniquePtr& io, size_t length);
 
-[[nodiscard]] std::string readStringTag(Exiv2::BasicIo::UniquePtr& io, uint16_t length = DWORD);
+[[nodiscard]] std::string readStringTag(Exiv2::BasicIo::UniquePtr& io, size_t length = DWORD);
 
 }  // namespace Exiv2
 #endif  // HELPER_FUNCTIONS_HPP
diff --git a/src/riffvideo.cpp b/src/riffvideo.cpp
index 4c525dfc..89683319 100644
--- a/src/riffvideo.cpp
+++ b/src/riffvideo.cpp
@@ -390,9 +390,7 @@ void RiffVideo::readMetadata() {
 
 RiffVideo::HeaderReader::HeaderReader(BasicIo::UniquePtr& io) {
   if (io->size() >= io->tell() + DWORD + DWORD) {
-    DataBuf IdBuf_ = io->read(DWORD);
-    id_ = Exiv2::toString(IdBuf_.data());
-
+    id_ = readStringTag(io);
     size_ = readDWORDTag(io);
   }
 }
@@ -719,7 +717,7 @@ void RiffVideo::readIndexChunk(uint64_t size_) {
 
 void RiffVideo::readDataChunk(uint64_t size_) {
 #ifdef EXIV2_DEBUG_MESSAGES
-  EXV_DEBUG << "--> Data               = " << readStringTag(size_) << std::endl;
+  EXV_DEBUG << "--> Data               = " << readStringTag(static_size<size_t>(size_)) << std::endl;
   if (size_ % 2 != 0) {
     EXV_DEBUG << "--> pad byte          = " << readStringTag(1) << std::endl;
   }