/***************************************************************************
    copyright            : (C) 2003 by Ismael Orenstein
    email                : orenstein@kde.org
 ***************************************************************************/

/***************************************************************************
 *   This library is free software; you can redistribute it and/or modify  *
 *   it  under the terms of the GNU Lesser General Public License version  *
 *   2.1 as published by the Free Software Foundation.                     *
 *                                                                         *
 *   This library is distributed in the hope that it will be useful, but   *
 *   WITHOUT ANY WARRANTY; without even the implied warranty of            *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU     *
 *   Lesser General Public License for more details.                       *
 *                                                                         *
 *   You should have received a copy of the GNU Lesser General Public      *
 *   License along with this library; if not, write to the Free Software   *
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  *
 *   USA                                                                   *
 ***************************************************************************/

#ifndef TAGLIB_XINGHEADER_H
#define TAGLIB_XINGHEADER_H

#include "mpegheader.h"

namespace TagLib {

  class ByteVector;

  namespace MPEG {

    //! An implementation of the Xing VBR headers

    /*!
     * This is a minimalistic implementation of the Xing VBR headers.  Xing
     * headers are often added to VBR (variable bit rate) MP3 streams to make it
     * easy to compute the length and quality of a VBR stream.  Our implementation
     * is only concerned with the total size of the stream (so that we can
     * calculate the total playing time and the average bitrate).  It uses
     * <a href="http://home.pcisys.net/~melanson/codecs/mp3extensions.txt">this text</a>
     * and the XMMS sources as references.
     */

    class XingHeader
    {
      public:
        /*!
	 * Parses a Xing header based on \a data.  The data must be at least 16
	 * bytes long (anything longer than this is discarded).
	 */
        XingHeader(const ByteVector &data);

        /*!
         * Destroy this XingHeader instance.
         */
        virtual ~XingHeader();

        /*!
         * Returns true if the data was parsed properly and if there is a vaild
	 * Xing header present.
         */
        bool isValid() const;

        /*!
         * Returns the total number of frames.
         */
        uint totalFrames() const;

        /*!
         * Returns the total size of stream in bytes.
         */
        uint totalSize() const;

        /*!
         * Returns the offset for the start of this Xing header, given the
	 * version and channels of the frame
         */
        static int xingHeaderOffset(TagLib::MPEG::Header::Version v,
                                    TagLib::MPEG::Header::ChannelMode c);

      private:
        void parse(const ByteVector &data);

	class XingHeaderPrivate;
	XingHeaderPrivate *d;
    };
  }
}

#endif