1 files changed, 283 insertions, 0 deletions
diff --git a/libs/evoral/src/SMFReader.cc b/libs/evoral/src/SMFReader.cc
new file mode 100644
index 0000000000..601cd7ac60
--- /dev/null
+++ b/libs/evoral/src/SMFReader.cc
@@ -0,0 +1,283 @@
+/*
+ * Copyright (C) 2008-2011 David Robillard <d@drobilla.net>
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <cstring>
+#include <cstdio>
+#include <cassert>
+#include <iostream>
+#include <glibmm/miscutils.h>
+
+#include "evoral/midi_util.h"
+#include "evoral/SMFReader.h"
+
+using namespace std;
+
+namespace Evoral {
+
+
+SMFReader::SMFReader(const string& filename)
+	: _fd(NULL)
+	, _ppqn(0)
+	, _track(0)
+	, _track_size(0)
+{
+	if (filename.length() > 0) {
+		open(filename);
+	}
+}
+
+
+SMFReader::~SMFReader()
+{
+	if (_fd)
+		close();
+}
+
+
+bool
+SMFReader::open(const string& filename) throw (logic_error, UnsupportedTime)
+{
+	if (_fd)
+		throw logic_error("Attempt to start new read while write in progress.");
+
+	cout << "Opening SMF file " << filename << " for reading." << endl;
+
+	_fd = fopen(filename.c_str(), "r+");
+
+	if (_fd) {
+		// Read type (bytes 8..9)
+		fseek(_fd, 0, SEEK_SET);
+		char mthd[5];
+		mthd[4] = '\0';
+		fread(mthd, 1, 4, _fd);
+		if (strcmp(mthd, "MThd")) {
+			cerr << filename << " is not an SMF file, aborting." << endl;
+			fclose(_fd);
+			_fd = NULL;
+			return false;
+		}
+
+		// Read type (bytes 8..9)
+		fseek(_fd, 8, SEEK_SET);
+		uint16_t type_be = 0;
+		fread(&type_be, 2, 1, _fd);
+		_type = GUINT16_FROM_BE(type_be);
+
+		// Read number of tracks (bytes 10..11)
+		uint16_t num_tracks_be = 0;
+		fread(&num_tracks_be, 2, 1, _fd);
+		_num_tracks = GUINT16_FROM_BE(num_tracks_be);
+
+		// Read PPQN (bytes 12..13)
+		uint16_t ppqn_be = 0;
+		fread(&ppqn_be, 2, 1, _fd);
+		_ppqn = GUINT16_FROM_BE(ppqn_be);
+
+		// TODO: Absolute (SMPTE seconds) time support
+		if ((_ppqn & 0x8000) != 0)
+			throw UnsupportedTime();
+
+		seek_to_track(1);
+
+		return true;
+	} else {
+		return false;
+	}
+}
+
+
+/** Seek to the start of a given track, starting from 1.
+ * Returns true if specified track was found.
+ */
+bool
+SMFReader::seek_to_track(unsigned track) throw (std::logic_error)
+{
+	if (track == 0)
+		throw logic_error("Seek to track 0 out of range (must be >= 1)");
+
+	if (!_fd)
+		throw logic_error("Attempt to seek to track on unopened SMF file.");
+
+	unsigned track_pos = 0;
+
+	fseek(_fd, 14, SEEK_SET);
+	char id[5];
+	id[4] = '\0';
+	uint32_t chunk_size = 0;
+
+	while (!feof(_fd)) {
+		fread(id, 1, 4, _fd);
+
+		if (!strcmp(id, "MTrk")) {
+			++track_pos;
+		} else {
+			std::cerr << "Unknown chunk ID " << id << endl;
+		}
+
+		uint32_t chunk_size_be;
+		fread(&chunk_size_be, 4, 1, _fd);
+		chunk_size = GUINT32_FROM_BE(chunk_size_be);
+
+		if (track_pos == track)
+			break;
+
+		fseek(_fd, chunk_size, SEEK_CUR);
+	}
+
+	if (!feof(_fd) && track_pos == track) {
+		_track = track;
+		_track_size = chunk_size;
+		return true;
+	} else {
+		return false;
+	}
+}
+
+
+/** 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 keep track of delta time, even for ignored events).
+ *
+ * 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,
+                      uint8_t*  buf,
+                      uint32_t* ev_size,
+                      uint32_t* delta_time)
+		throw (std::logic_error, PrematureEOF, CorruptFile)
+{
+	if (_track == 0)
+		throw logic_error("Attempt to read from unopened SMF file");
+
+	if (!_fd || feof(_fd)) {
+		return -1;
+	}
+
+	assert(buf_len > 0);
+	assert(buf);
+	assert(ev_size);
+	assert(delta_time);
+
+	// Running status state
+	static uint8_t  last_status = 0;
+	static uint32_t last_size   = 0;
+
+	*delta_time = read_var_len(_fd);
+	int status = fgetc(_fd);
+	if (status == EOF)
+		throw PrematureEOF();
+	else if (status > 0xFF)
+		throw CorruptFile();
+
+	if (status < 0x80) {
+		if (last_status == 0)
+			throw CorruptFile();
+		status = last_status;
+		*ev_size = last_size;
+		fseek(_fd, -1, SEEK_CUR);
+	} else {
+		last_status = status;
+		*ev_size = midi_event_size(status);
+		last_size = *ev_size;
+	}
+
+	buf[0] = (uint8_t)status;
+
+	if (status == 0xFF) {
+		*ev_size = 0;
+		if (feof(_fd))
+			throw PrematureEOF();
+		uint8_t type = fgetc(_fd);
+		const uint32_t size = read_var_len(_fd);
+		/*cerr.flags(ios::hex);
+		cerr << "SMF - meta 0x" << (int)type << ", size = ";
+		cerr.flags(ios::dec);
+		cerr << size << endl;*/
+
+		if ((uint8_t)type == 0x2F) {
+			return -1; // we hit the logical EOF anyway...
+		} else {
+			fseek(_fd, size, SEEK_CUR);
+			return 0;
+		}
+	}
+
+	if (*ev_size > buf_len || *ev_size == 0 || feof(_fd)) {
+		//cerr << "SMF - Skipping event" << endl;
+		// Skip event, return 0
+		fseek(_fd, *ev_size - 1, SEEK_CUR);
+		return 0;
+	} else {
+		// Read event, return size
+		if (ferror(_fd))
+			throw CorruptFile();
+
+		fread(buf+1, 1, *ev_size - 1, _fd);
+
+		if ((buf[0] & 0xF0) == 0x90 && buf[2] == 0) {
+			buf[0] = (0x80 | (buf[0] & 0x0F));
+			buf[2] = 0x40;
+		}
+
+		return *ev_size;
+	}
+}
+
+
+void
+SMFReader::close()
+{
+	if (_fd)
+		fclose(_fd);
+
+	_fd = NULL;
+}
+
+
+uint32_t
+SMFReader::read_var_len(FILE* fd) throw (PrematureEOF)
+{
+	if (feof(fd))
+		throw PrematureEOF();
+
+	uint32_t value;
+	uint8_t  c;
+
+	if ( (value = getc(fd)) & 0x80 ) {
+		value &= 0x7F;
+		do {
+			if (feof(fd))
+				throw PrematureEOF();
+			value = (value << 7) + ((c = getc(fd)) & 0x7F);
+		} while (c & 0x80);
+	}
+
+	return value;
+}
+
+
+} // namespace Evoral
+