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Diffstat (limited to 'src/SMFReader.cpp')
| -rw-r--r-- | src/SMFReader.cpp | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/src/SMFReader.cpp b/src/SMFReader.cpp new file mode 100644 index 0000000..ce4825c --- /dev/null +++ b/src/SMFReader.cpp @@ -0,0 +1,229 @@ +/* This file is part of Raul. + * Copyright (C) 2007 Dave Robillard <http://drobilla.net> + * + * Raul 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. + * + * Raul 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 <cstdio> +#include <cassert> +#include <iostream> +#include <glibmm/miscutils.h> +#include "raul/SMFReader.h" +#include "raul/midi_events.h" + +using namespace std; + +namespace Raul { + + +/** Return the size of the given event NOT including the status byte, + * or -1 if unknown (eg sysex) + */ +static int +midi_event_size(unsigned char status) +{ + if (status >= 0x80 && status <= 0xE0) { + status &= 0xF0; // mask off the channel + } + + switch (status) { + case MIDI_CMD_NOTE_OFF: + case MIDI_CMD_NOTE_ON: + case MIDI_CMD_NOTE_PRESSURE: + case MIDI_CMD_CONTROL: + case MIDI_CMD_BENDER: + case MIDI_CMD_COMMON_SONG_POS: + return 2; + + case MIDI_CMD_PGM_CHANGE: + case MIDI_CMD_CHANNEL_PRESSURE: + case MIDI_CMD_COMMON_MTC_QUARTER: + case MIDI_CMD_COMMON_SONG_SELECT: + return 1; + + case MIDI_CMD_COMMON_TUNE_REQUEST: + case MIDI_CMD_COMMON_SYSEX_END: + case MIDI_CMD_COMMON_CLOCK: + case MIDI_CMD_COMMON_START: + case MIDI_CMD_COMMON_CONTINUE: + case MIDI_CMD_COMMON_STOP: + case MIDI_CMD_COMMON_SENSING: + case MIDI_CMD_COMMON_RESET: + return 0; + + case MIDI_CMD_COMMON_SYSEX: + return -1; + } + + return -1; +} + + +SMFReader::SMFReader() + : _fd(NULL) + , _ppqn(0) + , _last_ev_time(0) + , _track_size(0) +{ +} + + +SMFReader::~SMFReader() +{ + if (_fd) + close(); +} + + +bool +SMFReader::open(const string& filename) +{ + if (_fd) + throw logic_error("Attempt to start new read while write in progress."); + + cerr << "Opening SMF file " << filename << " for reading." << endl; + + _fd = fopen(filename.c_str(), "r+"); + + if (_fd) { + // Read PPQN + // FIXME: broken for time-based divisions + fseek(_fd, 12, SEEK_SET); + uint16_t ppqn_be = 0; + fread(&ppqn_be, 2, 1, _fd); + _ppqn = GUINT16_FROM_BE(ppqn_be); + + // Read Track size + fseek(_fd, 18, SEEK_SET); + uint32_t track_size_be = 0; + fread(&track_size_be, 4, 1, _fd); + _track_size = GUINT32_FROM_BE(track_size_be); + std::cerr << "SMF - read track size " << _track_size << std::endl; + + _last_ev_time = 0; + return true; + } else { + return false; + } +} + + +size_t +SMFReader::num_tracks() throw (logic_error) +{ + if (!_fd) + throw logic_error("num_tracks called without an open SMF file."); + + return 1; +} + + +/** Read an event from the current position in file. + * + * File position MUST be at the beginning of a delta time, or this will die very messily. + * ev.buffer must be of size ev.size, and large enough for the event. The returned event + * will have it's time field set to it's delta time (so it's the caller's responsibility + * to calculate a real time for the event). + * + * Returns event length (including status byte) on success, 0 if event was + * skipped (eg a meta event), or -1 on EOF (or end of track). + * + * If @a buf is not large enough to hold the event, 0 will be returned, but ev_size + * set to the actual size of the event. + */ +int +SMFReader::read_event(size_t buf_len, char* buf, size_t* ev_size, uint64_t* ev_time) +{ + // - 4 is for the EOT event, which we don't actually want to read + //if (feof(_fd) || ftell(_fd) >= HEADER_SIZE + _track_size - 4) { + if (feof(_fd)) { + return -1; + } + + assert(buf_len > 0); + assert(buf); + assert(ev_size); + assert(ev_time); + + uint32_t delta_time = read_var_len(); + int status = fgetc(_fd); + assert(status != EOF); // FIXME die gracefully + if (status == 0xFF) { + assert(!feof(_fd)); + int type = fgetc(_fd); + if ((unsigned char)type == 0x2F) { + //cerr << "SMF - hit EOT" << endl; + return -1; // we hit the logical EOF anyway... + } else { + ev_size = 0; + *ev_time = _last_ev_time + delta_time; // this is needed regardless + _last_ev_time = *ev_time; + return 0; + } + } + + buf[0] = (unsigned char)status; + *ev_size = midi_event_size(buf[0]) + 1; + if (*ev_size > buf_len) + return 0; + fread(buf+1, 1, *ev_size - 1, _fd); + *ev_time = _last_ev_time + delta_time; + _last_ev_time = *ev_time; + + /*printf("SMF - read event, delta = %u, size = %zu, data = ", + delta_time, ev.size); + for (size_t i=0; i < ev.size; ++i) { + printf("%X ", ev.buffer[i]); + } + printf("\n");*/ + + return *ev_size; +} + + +void +SMFReader::close() +{ + if (_fd) + fclose(_fd); + + _fd = NULL; +} + + +uint32_t +SMFReader::read_var_len() const +{ + assert(!feof(_fd)); + + //int offset = ftell(_fd); + //cerr << "SMF - reading var len at " << offset << endl; + + uint32_t value; + unsigned char c; + + if ( (value = getc(_fd)) & 0x80 ) { + value &= 0x7F; + do { + assert(!feof(_fd)); + value = (value << 7) + ((c = getc(_fd)) & 0x7F); + } while (c & 0x80); + } + + return value; +} + + +} // namespace Raul + |