Merge branch 'filetype-detection' of https://github.com/TsudaKageyu/taglib into filetype-detection

3 files changed, 11 insertions, 14 deletions

diff --git a/taglib/mpeg/mpegfile.cpp b/taglib/mpeg/mpegfile.cpp
index 75478ed8..217b03dd 100644
--- a/taglib/mpeg/mpegfile.cpp
+++ b/taglib/mpeg/mpegfile.cpp
@@ -105,23 +105,15 @@ bool MPEG::File::isSupported(IOStream *stream)
   // MPEG frame headers are really confusing with irrelevant binary data.
   // So we check if a frame header is really valid.
 
-  const long originalPosition = stream->tell();
-
-  long bufferOffset = 0;
-
-  stream->seek(0);
-  const ByteVector data = stream->readBlock(ID3v2::Header::size());
-  if(data.startsWith(ID3v2::Header::fileIdentifier()))
-    bufferOffset = ID3v2::Header(data).completeTagSize();
-
-  stream->seek(bufferOffset);
-  const ByteVector buffer = stream->readBlock(bufferSize());
+  long headerOffset;
+  const ByteVector buffer = Utils::readHeader(stream, bufferSize(), true, &headerOffset);
 
+  const long originalPosition = stream->tell();
   AdapterFile file(stream);
 
   for(unsigned int i = 0; i < buffer.size() - 1; ++i) {
     if(isFrameSync(buffer, i)) {
-      const Header header(&file, bufferOffset + i, true);
+      const Header header(&file, headerOffset + i, true);
       if(header.isValid()) {
         stream->seek(originalPosition);
         return true;
diff --git a/taglib/tagutils.cpp b/taglib/tagutils.cpp
index e27fd8bd..d6d92406 100644
--- a/taglib/tagutils.cpp
+++ b/taglib/tagutils.cpp
@@ -78,7 +78,8 @@ long Utils::findAPE(File *file, long id3v1Location)
   return -1;
 }
 
-ByteVector TagLib::Utils::readHeader(IOStream *stream, unsigned int length, bool skipID3v2)
+ByteVector TagLib::Utils::readHeader(IOStream *stream, unsigned int length,
+                                     bool skipID3v2, long *headerOffset)
 {
   if(!stream || !stream->isOpen())
     return ByteVector();
@@ -97,5 +98,8 @@ ByteVector TagLib::Utils::readHeader(IOStream *stream, unsigned int length, bool
   const ByteVector header = stream->readBlock(length);
   stream->seek(originalPosition);
 
+  if(headerOffset)
+    *headerOffset = bufferOffset;
+
   return header;
 }
diff --git a/taglib/tagutils.h b/taglib/tagutils.h
index 4014c673..4488a32b 100644
--- a/taglib/tagutils.h
+++ b/taglib/tagutils.h
@@ -45,7 +45,8 @@ namespace TagLib {
 
     long findAPE(File *file, long id3v1Location);
 
-    ByteVector readHeader(IOStream *stream, unsigned int length, bool skipID3v2);
+    ByteVector readHeader(IOStream *stream, unsigned int length, bool skipID3v2,
+                          long *headerOffset = 0);
   }
 }