OldSMF.cpp

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/* This file is part of Evoral.
 * Copyright (C) 2008 David Robillard <http://drobilla.net>
 * Copyright (C) 2000-2008 Paul Davis
 *
 * Evoral 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.
 *
 * Evoral 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 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.,
 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <cassert>
#include <iostream>
#include <glibmm/miscutils.h>
#include "evoral/midi_util.h"
#include "evoral/OldSMF.hpp"
#include "evoral/SMFReader.hpp"
#include "evoral/Event.hpp"

using namespace std;

namespace Evoral {

template<typename Time>
SMF<Time>::SMF()
        : _fd(0)
        , _last_ev_time(0)
        , _track_size(4) // 4 bytes for the ever-present EOT event
        , _header_size(22)
        , _empty(true)
{
}

template<typename Time>
SMF<Time>::~SMF()
{
}

template<typename Time>
int
SMF<Time>::open(const std::string& path) THROW_FILE_ERROR

{
        //cerr << "Opening SMF file " << path() << " writeable: " << writable() << endl;
        _fd = fopen(path.c_str(), "r+");

        // File already exists
        if (_fd) {
                fseek(_fd, _header_size - 4, 0);
                uint32_t track_size_be = 0;
                fread(&track_size_be, 4, 1, _fd);
                _track_size = GUINT32_FROM_BE(track_size_be);
                _empty = _track_size > 4;
                //cerr << "SMF - read track size " << _track_size << endl;

        // We're making a new file
        } else {
                _fd = fopen(path.c_str(), "w+");
                if (_fd == NULL) {
                        cerr << "ERROR: Can not open SMF file " << path << " for writing: " <<
                                strerror(errno) << endl;
                        return -2;
                }
                _track_size = 4;
                _empty = true;

                // Write a tentative header just to pad things out so writing happens in the right spot
                flush_header();
                flush_footer();
        }

        return (_fd == 0) ? -1 : 0;
}

template<typename Time>
void
SMF<Time>::close() THROW_FILE_ERROR
{
        if (_fd) {
                flush_header();
                flush_footer();
                fclose(_fd);
                _fd = NULL;
        }
}

template<typename Time>
void
SMF<Time>::seek_to_start() const
{
        fseek(_fd, _header_size, SEEK_SET);
}

template<typename Time>
void
SMF<Time>::seek_to_footer_position()
{
        uint8_t buffer[4];

        // Check if there is a track end marker at the end of the data
        fseek(_fd, -4, SEEK_END);
        size_t read_bytes = fread(buffer, sizeof(uint8_t), 4, _fd);

        if ((read_bytes == 4)
                        && buffer[0] == 0x00
                        && buffer[1] == 0xFF
                        && buffer[2] == 0x2F
                        && buffer[3] == 0x00) {
                // there is one, so overwrite it
                fseek(_fd, -4, SEEK_END);
        } else {
                // there is none, so append
                fseek(_fd, 0, SEEK_END);
        }
}

template<typename Time>
void
SMF<Time>::flush()
{
        fflush(_fd);
}

template<typename Time>
int
SMF<Time>::flush_header()
{
        // FIXME: write timeline position somehow?

        //cerr << path() << " SMF Flushing header\n";

        assert(_fd);

        const uint16_t type     = GUINT16_TO_BE(0);     // SMF Type 0 (single track)
        const uint16_t ntracks  = GUINT16_TO_BE(1);     // Number of tracks (always 1 for Type 0)
        const uint16_t division = GUINT16_TO_BE(_ppqn); // Pulses per quarter note (beat)

        char data[6];
        memcpy(data, &type, 2);
        memcpy(data+2, &ntracks, 2);
        memcpy(data+4, &division, 2);

        //_fd = freopen(path().c_str(), "r+", _fd);
        //assert(_fd);
        fseek(_fd, 0, SEEK_SET);
        write_chunk("MThd", 6, data);
        write_chunk_header("MTrk", _track_size);

        fflush(_fd);

        return 0;
}

template<typename Time>
int
SMF<Time>::flush_footer()
{
        //cerr << path() << " SMF Flushing footer\n";
        seek_to_footer_position();
        write_footer();
        seek_to_footer_position();

        return 0;
}

template<typename Time>
void
SMF<Time>::write_footer()
{
        write_var_len(0);
        char eot[3] = { 0xFF, 0x2F, 0x00 }; // end-of-track meta-event
        fwrite(eot, 1, 3, _fd);
        fflush(_fd);
}


template<typename Time>
int
SMF<Time>::read_event(uint32_t* delta_t, uint32_t* size, uint8_t** buf) const
{
        if (feof(_fd)) {
                return -1;
        }

        assert(delta_t);
        assert(size);
        assert(buf);

        try {
                *delta_t = SMFReader::read_var_len(_fd);
        } catch (...) {
                return -1; // Premature EOF
        }

        if (feof(_fd)) {
                return -1; // Premature EOF
        }

        const int status = fgetc(_fd);

        if (status == EOF) {
                return -1; // Premature EOF
        }

        //printf("Status @ %X = %X\n", (unsigned)ftell(_fd) - 1, status);

        if (status == 0xFF) {
                if (feof(_fd)) {
                        return -1; // Premature EOF
                }
                const int type = fgetc(_fd);
                if ((unsigned char)type == 0x2F) {
                        return -1; // hit end of track
                } else {
                        *size = 0;
                        return 0;
                }
        }

        int event_size = midi_event_size((unsigned char)status);
        if (event_size <= 0) {
                if ((status & 0xff) == MIDI_CMD_COMMON_SYSEX) {
                event_size = SMFReader::read_var_len(_fd) + 1;
                } else {
                        *size = 0;
                        return 0;
                }
        }

        // Make sure we have enough scratch buffer
        if (*size < (unsigned)event_size)
                *buf = (uint8_t*)realloc(*buf, event_size);

        *size = event_size;

        (*buf)[0] = (unsigned char)status;
        if (event_size > 1)
                fread((*buf) + 1, 1, *size - 1, _fd);

        /*printf("SMF read event: delta = %u, size = %u, data = ",  *delta_t, *size);
        for (size_t i=0; i < *size; ++i) {
                printf("%X ", (*buf)[i]);
        }
        printf("\n");*/

        return (int)*size;
}

template<typename Time>
void
SMF<Time>::append_event_delta(uint32_t delta_t, const Event<Time>& ev)
{
        if (ev.size() == 0)
                return;

        size_t stamp_size = write_var_len(delta_t);
        if (ev.buffer()[0] == MIDI_CMD_COMMON_SYSEX) {
                fputc(MIDI_CMD_COMMON_SYSEX, _fd);
                stamp_size += write_var_len(ev.size() - 1);
                fwrite(ev.buffer() + 1, 1, ev.size() - 1, _fd);
        } else {
                fwrite(ev.buffer(), 1, ev.size(), _fd);
        }

        _track_size += stamp_size + ev.size();
        _last_ev_time = ev.time();

        if (ev.size() > 0)
                _empty = false;
}

template<typename Time>
void
SMF<Time>::begin_write()
{
        _last_ev_time = 0;
        fseek(_fd, _header_size, SEEK_SET);
}

template<typename Time>
void
SMF<Time>::end_write()
{
        flush_header();
        flush_footer();
}

template<typename Time>
void
SMF<Time>::write_chunk_header(const char id[4], uint32_t length)
{
        const uint32_t length_be = GUINT32_TO_BE(length);

        fwrite(id, 1, 4, _fd);
        fwrite(&length_be, 4, 1, _fd);
}

template<typename Time>
void
SMF<Time>::write_chunk(const char id[4], uint32_t length, void* data)
{
        write_chunk_header(id, length);

        fwrite(data, 1, length, _fd);
}

template<typename Time>
size_t
SMF<Time>::write_var_len(uint32_t value)
{
        size_t ret = 0;

        uint32_t buffer = value & 0x7F;

        while ( (value >>= 7) ) {
                buffer <<= 8;
                buffer |= ((value & 0x7F) | 0x80);
        }

        while (true) {
                //printf("Writing var len byte %X\n", (unsigned char)buffer);
                ++ret;
                fputc(buffer, _fd);
                if (buffer & 0x80)
                        buffer >>= 8;
                else
                        break;
        }

        return ret;
}

template class SMF<Evoral::Beats>;

} // namespace Evoral