SMF reading/writing fixes.

git-svn-id: http://svn.drobilla.net/lad/raul@345 a436a847-0d15-0410-975c-d299462d15a1

3 files changed, 247 insertions, 29 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index ada7848..646eacc 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -8,6 +8,7 @@ libraul_la_SOURCES = \
 	Path.cpp \
 	Namespaces.cpp \
 	Maid.cpp \
+	SMFReader.cpp \
 	SMFWriter.cpp
 
 if WITH_RAPTOR
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
+
diff --git a/src/SMFWriter.cpp b/src/SMFWriter.cpp
index 7db6c5f..0af7688 100644
--- a/src/SMFWriter.cpp
+++ b/src/SMFWriter.cpp
@@ -49,37 +49,23 @@ SMFWriter::~SMFWriter()
  *    to write_event will have this value subtracted before writing).
  */
 bool
-SMFWriter::start(const string& filename,
-                 Raul::BeatTime     start_time) throw (logic_error)
+SMFWriter::start(const string&  filename,
+                 Raul::BeatTime start_time) throw (logic_error)
 {
 	if (_fd)
 		throw logic_error("Attempt to start new write while write in progress.");
 
-	cerr << "Opening SMF file " << filename << endl;
-
-	_fd = fopen(filename.c_str(), "r+");
-
-	// File already exists
-	if (_fd) {
-		return false;
-		/*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);
-		cerr << "SMF - read track size " << _track_size;*/
-
-	// Make a new file
-	} else {
-		_fd = fopen(filename.c_str(), "w+");
-
-		if (_fd) { 
-			_track_size = 0;
-			_filename = filename;
-			_start_time = start_time;
-			_last_ev_time = 0;
-			// write a tentative header to pad file out so writing starts at the right offset
-			write_header();
-		}
+	cerr << "Opening SMF file " << filename << " for writing." << endl;
+
+	_fd = fopen(filename.c_str(), "w+");
+
+	if (_fd) { 
+		_track_size = 0;
+		_filename = filename;
+		_start_time = start_time;
+		_last_ev_time = 0;
+		// write a tentative header to pad file out so writing starts at the right offset
+		write_header();
 	}
 
 	return (_fd == 0) ? -1 : 0;
@@ -192,7 +178,7 @@ SMFWriter::finish() throw (logic_error)
 
 
 void
-SMFWriter::write_header ()
+SMFWriter::write_header()
 {
 	cerr << "SMF Flushing header\n";
 
@@ -200,12 +186,14 @@ SMFWriter::write_header ()
 
 	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(1920); // FIXME FIXME FIXME PPQN
+	const uint16_t division = GUINT16_TO_BE(_ppqn);    // Number of tracks (always 1 for Type 0)
 
 	char data[6];
 	memcpy(data, &type, 2);
 	memcpy(data+2, &ntracks, 2);
 	memcpy(data+4, &division, 2);
+	//data[4] = _ppqn & 0xF0;
+	//data[5] = _ppqn & 0x0F;
 
 	_fd = freopen(_filename.c_str(), "r+", _fd);
 	assert(_fd);