MIDIReader.hxx

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/*
 * Copyright (c) 2001-2004 MUSIC TECHNOLOGY GROUP (MTG)
 * UNIVERSITAT POMPEU FABRA
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * MIDIFileReader C++ classes
 * This code is part of the CLAM library, but also usable stand-alone.
 * Maarten de Boer <mdeboer@iua.upf.es>
 *
 */
#ifndef __MIDIReader__
#define __MIDIReader__

#include <stdio.h>
#include <CLAM/MIDIDataTypes.hxx>
#include "MIDIChunkType.hxx"

namespace MIDI
{
        class Song;

        class Reader
        /* class to read midi data from a file, parse it and store it in a song;
        */
        {
        private:
                FILE* mFile;
                int mCnt;
        public:
                Reader(const char* filename)
                {
                        mFile = fopen(filename,"rb");
                }
                bool Ok(void)
                {
                        return mFile!=NULL;
                }
                Byte GetByte(void)
                {
                        mCnt++;
                        return fgetc(mFile);
                }
                unsigned int GetInt(void)
                {
                        unsigned int val;

                        val = GetByte();
                        val <<=8;
                        val |= GetByte();
                        val <<=8;
                        val |= GetByte();
                        val <<=8;
                        val |= GetByte();
                        
                        return val;
                }
                unsigned short GetShort(void)
                {
                        unsigned short val;

                        val = GetByte();
                        val <<= 8;
                        val |= GetByte();

                        return val;
                }

                ChunkType GetChunkType(void)
                {
                        Byte bytes[4];
                        for (int i=0;i<4;i++) bytes[i] = GetByte();
                        return ChunkType(bytes);
                }

                unsigned int GetVarLength(void)
                {
                        /* read a variable lenght value. see midi file spec */
                        unsigned int ret = 0;
                        Byte tmp;

                        tmp = GetByte();
                        ret = tmp&0x7F;
                        while (tmp&0x80)
                        {
                                tmp = GetByte();
                                ret <<= 7;
                                ret |= (tmp&0x7F);
                        }
                        return ret;
                }

                class Error
                {
                public:
                        const char* mStr;
                        Error(const char* str):mStr(str) { printf(str); }
                };

                void Read(Song& s);
        };

}

#endif