Merge pull request #799 from TsudaKageyu/filetype-detection

Enable FileRef to detect file types by the actual content of a stream.

2 files changed, 22 insertions, 0 deletions

diff --git a/taglib/asf/asffile.cpp b/taglib/asf/asffile.cpp
index 8f395265..d5a80bca 100644
--- a/taglib/asf/asffile.cpp
+++ b/taglib/asf/asffile.cpp
@@ -27,6 +27,7 @@
 #include <tbytevectorlist.h>
 #include <tpropertymap.h>
 #include <tstring.h>
+#include <tagutils.h>
 
 #include "asffile.h"
 #include "asftag.h"
@@ -474,6 +475,18 @@ void ASF::File::FilePrivate::CodecListObject::parse(ASF::File *file, unsigned in
 }
 
 ////////////////////////////////////////////////////////////////////////////////
+// static members
+////////////////////////////////////////////////////////////////////////////////
+
+bool ASF::File::isSupported(IOStream *stream)
+{
+  // An ASF file has to start with the designated GUID.
+
+  const ByteVector id = Utils::readHeader(stream, 16, false);
+  return (id == headerGuid);
+}
+
+////////////////////////////////////////////////////////////////////////////////
 // public members
 ////////////////////////////////////////////////////////////////////////////////
 
diff --git a/taglib/asf/asffile.h b/taglib/asf/asffile.h
index b674da79..05cf4ee2 100644
--- a/taglib/asf/asffile.h
+++ b/taglib/asf/asffile.h
@@ -115,6 +115,15 @@ namespace TagLib {
        */
       virtual bool save();
 
+      /*!
+       * Returns whether or not the given \a stream can be opened as an ASF
+       * file.
+       *
+       * \note This method is designed to do a quick check.  The result may
+       * not necessarily be correct.
+       */
+      static bool isSupported(IOStream *stream);
+
     private:
       void read();