Пример #1
0
        ///
        /// Reads a subset of the id3 information
        ///
        public ID3v2( string path, bool verboseDump )
        {
            _debugDump = verboseDump;

             _stream = new FileStream( path,
                                   FileMode.Open,
                                   FileAccess.Read,
                                   FileShare.Read );
             _reader = new Mp3StreamReader( _stream );
             try
             {
            // Find the start of the ID3v2 tag in our stream:
            _header = _FindHeader( false );
            Debug.Assert( null != _header );

            if (_debugDump)
            {
               _Trace( "  isValid: " + _header.isValid );
               _Trace( "  version: " + _header.version );
               _Trace( "  flags: " + _header.flags );
               _Trace( "  isUnsynchronized: " + _header.isUnsynchronized );
               _Trace( "  hasExtendedHeader: " + _header.hasExtendedHeader );
               _Trace( "  isExperimental: " + _header.isExperimental );
               _Trace( "  hasFooter: " + _header.hasFooter );
               _Trace( "  size: " + _header.size );
            }

            if (_header.isUnsynchronized)
            {
               throw new ApplicationException(
                  "Sorry, whole-tag unsynchronization not yet implemented" );
            }

            // For now, forget about it
            _SkipExtendedHeader(); // skip to the meat

            // Finally, start looking for interesting information in the
            // stream.
            _ReadFrames();

             }
             catch (ID3TagNotFoundException nfe)
             {
            _header = null;     // not found. Boo!
             }
             finally
             {
            _reader = null;

            _stream.Close();
            _stream = null;
             }
        }
Пример #2
0
        ///
        /// \param tryTheEnd - if false, we only look in the first 3 bytes
        ///   for a header.
        ///
        ID3v2Header _FindHeader( bool tryTheEnd )
        {
            // look for the tag at the start or end of the file. If it's
             // somewhere in the middle, forget it.

             /// \bug We should be ready to deal with id3 tags in the middle
             ///   of the file, but this isn't very likely, so...

             // From the FAQ:
             // # Q: Where is an ID3v2 tag located in an MP3 file?
             //   It is most likely located at the beginning of the file.
             //
             //   Look for the marker "ID3" in the first 3 bytes of the file.
             //
             //   If it's not there, it could be at the end of the file
             //   (if the tag is ID3v2.4). Look for the marker "3DI" 10
             //   bytes from the end of the file, or 10 bytes before the
             //   beginning of an ID3v1 tag.
             //
             //   Finally it is possible to embed ID3v2 tags in the actual
             //   MPEG stream, on an MPEG frame boundry. Almost nobody does
             //   this.
             //

             // Try the start
             byte [] buffer = new byte[10];

             _reader.Read( buffer, 10 ); // get the file header

             ID3v2Header header = new ID3v2Header( buffer, true );
             if (header.isValid)
             {
            if (_debugDump)
               _Trace( "  Found header at start" );

            return header;
             }

             if (!tryTheEnd)
             {
            /// \todo search for id3v2 tag in the middle of the file
            ///

            throw new ID3TagNotFoundException();
             }

             // Seek to end of file (new for 2.4)
             _Trace( "FIXME: look for ID3v2.4 tag at EOF" );
             throw new ID3TagNotFoundException();
        }