Separate low level details of SMF reading/writing from concept of 'midi source in ardour'.

git-svn-id: svn://localhost/ardour2/branches/3.0@3839 d708f5d6-7413-0410-9779-e7cbd77b26cf

8 files changed, 51 insertions, 752 deletions

diff --git a/libs/ardour/SConscript b/libs/ardour/SConscript
index f310e7ca0f..b117b41b7a 100644
--- a/libs/ardour/SConscript
+++ b/libs/ardour/SConscript
@@ -152,7 +152,6 @@ session_time.cc
 session_transport.cc
 session_utils.cc
 silentfilesource.cc
-smf_reader.cc
 smf_source.cc
 sndfile_helpers.cc
 sndfileimportable.cc
diff --git a/libs/ardour/ardour/midi_source.h b/libs/ardour/ardour/midi_source.h
index 9cb222d207..895dcb25cc 100644
--- a/libs/ardour/ardour/midi_source.h
+++ b/libs/ardour/ardour/midi_source.h
@@ -95,8 +95,9 @@ class MidiSource : public Source
 	void set_model(boost::shared_ptr<MidiModel> m) { _model = m; }
 
   protected:
-	virtual int flush_header() = 0;
-	virtual int flush_footer() = 0;
+	virtual void flush_midi() = 0;
+	//virtual int flush_header() = 0;
+	//virtual int flush_footer() = 0;
 	
 	virtual nframes_t read_unlocked (MidiRingBuffer& dst, nframes_t start, nframes_t cnt, nframes_t stamp_offset, nframes_t negative_stamp_offset) const = 0;
 	virtual nframes_t write_unlocked (MidiRingBuffer& dst, nframes_t cnt) = 0;
diff --git a/libs/ardour/ardour/smf_reader.h b/libs/ardour/ardour/smf_reader.h
deleted file mode 100644
index e41dcc3bc4..0000000000
--- a/libs/ardour/ardour/smf_reader.h
+++ /dev/null
@@ -1,87 +0,0 @@
-/*
-    Copyright (C) 2008 Paul Davis 
-    Written by Dave Robillard
-
-    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., 675 Mass Ave, Cambridge, MA 02139, USA.
-*/
-
-#ifndef __ardour_smf_reader_h__ 
-#define __ardour_smf_reader_h__
-
-#include <exception>
-#include <stdexcept>
-#include <string>
-#include <inttypes.h>
-
-namespace ARDOUR {
-
-
-/** Standard MIDI File (Type 0) Reader
- *
- * Currently this only reads SMF files with tempo-based timing.
- */
-class SMFReader {
-public:
-	class PrematureEOF : public std::exception {
-		const char* what() const throw() { return "Unexpected end of file"; }
-	};
-	class CorruptFile : public std::exception {
-		const char* what() const throw() { return "Corrupted file"; }
-	};
-	class UnsupportedTime : public std::exception {
-		const char* what() const throw() { return "Unsupported time stamp type (SMPTE)"; }
-	};
-
-	SMFReader(const std::string filename="");
-	~SMFReader();
-
-	bool open(const std::string& filename) throw (std::logic_error, UnsupportedTime);
-
-	bool seek_to_track(unsigned track) throw (std::logic_error);
-	
-	const std::string& filename() const { return _filename; };
-
-	uint16_t type()       const { return _type; }
-	uint16_t ppqn()       const { return _ppqn; }
-	uint16_t num_tracks() const { return _num_tracks; }
-	
-	int read_event(size_t    buf_len,
-	               uint8_t*  buf,
-	               uint32_t* ev_size,
-	               uint32_t* ev_delta_time)
-		throw (std::logic_error, PrematureEOF, CorruptFile);
-	
-	void close();
-	
-	static uint32_t read_var_len(FILE* fd) throw (PrematureEOF);
-
-protected:
-	/** size of SMF header, including MTrk chunk header */
-	static const uint32_t HEADER_SIZE = 22;
-
-	std::string _filename;
-	FILE*       _fd;
-	uint16_t    _type;
-	uint16_t    _ppqn;
-	uint16_t    _num_tracks;
-	uint32_t    _track;
-	uint32_t    _track_size;
-};
-
-
-} // namespace ARDOUR
-
-#endif /* __ardour_smf_reader_h__ */
-
diff --git a/libs/ardour/ardour/smf_source.h b/libs/ardour/ardour/smf_source.h
index 3217c8e3e8..7d114d49ed 100644
--- a/libs/ardour/ardour/smf_source.h
+++ b/libs/ardour/ardour/smf_source.h
@@ -25,6 +25,7 @@
 #include <time.h>
 
 #include <ardour/midi_source.h>
+#include <evoral/SMF.hpp>
 
 namespace Evoral { class Event; }
 
@@ -33,7 +34,7 @@ namespace ARDOUR {
 class MidiRingBuffer;
 
 /** Standard Midi File (Type 0) Source */
-class SMFSource : public MidiSource {
+class SMFSource : public MidiSource, public Evoral::SMF {
   public:
 	enum Flag {
 		Writable = 0x1,
@@ -67,7 +68,7 @@ class SMFSource : public MidiSource {
 	int set_source_name (string newname, bool destructive);
 	
 	static bool safe_file_extension (const Glib::ustring& path);
-
+	
 	Glib::ustring path() const { return _path; }
 
 	void set_allow_remove_if_empty (bool yn);
@@ -75,12 +76,8 @@ class SMFSource : public MidiSource {
 
 	void append_event_unlocked(EventTimeUnit unit, const Evoral::Event& ev);
 
-	int flush_header ();
-	int flush_footer ();
-	
 	int move_to_trash (const string trash_dir_name);
 
-	bool is_empty () const;
 	void mark_streaming_midi_write_started (NoteMode mode, nframes_t start_time);
 	void mark_streaming_write_completed ();
 
@@ -93,56 +90,34 @@ class SMFSource : public MidiSource {
 	XMLNode& get_state ();
 	int set_state (const XMLNode&);
 
-	void seek_to(nframes_t time);
-	
 	void load_model(bool lock=true, bool force_reload=false);
 	void destroy_model();
 
-	uint16_t ppqn() const { return _ppqn; }
+	void flush_midi();
 
   private:
 
 	int init (string idstr, bool must_exist);
 
-	nframes_t read_unlocked (MidiRingBuffer& dst, nframes_t start, nframes_t cn, nframes_t stamp_offset, nframes_t negative_stamp_offset) const;
-	nframes_t write_unlocked (MidiRingBuffer& dst, nframes_t cnt);
+	nframes_t read_unlocked (
+			MidiRingBuffer& dst,
+			nframes_t start,
+			nframes_t cn,
+			nframes_t stamp_offset,
+			nframes_t negative_stamp_offset) const;
+
+	nframes_t write_unlocked (
+			MidiRingBuffer& src,
+			nframes_t cnt);
 
 	bool find (std::string path, bool must_exist, bool& is_new);
 	bool removable() const;
 	bool writable() const { return _flags & Writable; }
 
-	int  open();
-	void close();
-	
-	/**
-	 * This method is only used by flush_footer() to find the right seek position 
-	 * for the footer (at the end after recording or -4 offset ro SEEK_END
-	 * if a footer is already present)
-	 */
-	void seek_to_footer_position();
-	
-	/**
-	 * write the track footer at the current seek position
-	 */
-	void write_footer();
-
-	void     write_chunk_header(const char id[4], uint32_t length);
-	void     write_chunk(const char id[4], uint32_t length, void* data);
-	size_t   write_var_len(uint32_t val);
-	uint32_t read_var_len() const;
-	int      read_event(uint32_t* delta_t, uint32_t* size, uint8_t** buf) const;
-
-	static const uint16_t _ppqn = 19200;
-
 	Glib::ustring  _path;
 	Flag           _flags;
 	string         _take_id;
 	bool           _allow_remove_if_empty;
-	FILE*          _fd;
-	double         _last_ev_time; ///< last frame time written, relative to source start
-	uint32_t       _track_size;
-	uint32_t       _header_size; ///< size of SMF header, including MTrk chunk header
-	bool           _empty; ///< true iff file contains (non-empty) events
 
 	static string _search_path;
 };
diff --git a/libs/ardour/import.cc b/libs/ardour/import.cc
index 370991be5f..3f6e60af33 100644
--- a/libs/ardour/import.cc
+++ b/libs/ardour/import.cc
@@ -37,6 +37,8 @@
 #include <pbd/basename.h>
 #include <pbd/convert.h>
 
+#include <evoral/SMFReader.hpp>
+
 #include <ardour/ardour.h>
 #include <ardour/session.h>
 #include <ardour/session_directory.h>
@@ -50,7 +52,6 @@
 #include <ardour/resampled_source.h>
 #include <ardour/sndfileimportable.h>
 #include <ardour/analyser.h>
-#include <ardour/smf_reader.h>
 #include <ardour/smf_source.h>
 #include <ardour/tempo.h>
 
@@ -302,7 +303,7 @@ write_audio_data_to_new_files (ImportableSource* source, Session::import_status&
 }
 
 static void
-write_midi_data_to_new_files (SMFReader* source, Session::import_status& status,
+write_midi_data_to_new_files (Evoral::SMFReader* source, Session::import_status& status,
 			       vector<boost::shared_ptr<Source> >& newfiles)
 {
 	Evoral::Event ev(0, 0.0, 4, NULL, true);
@@ -344,9 +345,7 @@ write_midi_data_to_new_files (SMFReader* source, Session::import_status& status,
 					smfs->session().tempo_map().meter_at(timeline_position));
 
 		smfs->update_length(0, (nframes_t) ceil ((t / (double)source->ppqn()) * frames_per_beat));
-
-		smfs->flush_header();
-		smfs->flush_footer();
+		smfs->end_write();
 
 		if (status.cancel)
 			break;
@@ -384,7 +383,7 @@ Session::import_audiofiles (import_status& status)
 			++p, ++cnt)
 	{
 		boost::shared_ptr<ImportableSource> source;
-		std::auto_ptr<SMFReader>            smf_reader;
+		std::auto_ptr<Evoral::SMFReader>    smf_reader;
 		const DataType type = ((*p).rfind(".mid") != string::npos) ? 
 			DataType::MIDI : DataType::AUDIO;
 		
@@ -400,9 +399,9 @@ Session::import_audiofiles (import_status& status)
 
 		} else {
 			try {
-				smf_reader = std::auto_ptr<SMFReader>(new SMFReader(*p));
+				smf_reader = std::auto_ptr<Evoral::SMFReader>(new Evoral::SMFReader(*p));
 				channels = smf_reader->num_tracks();
-			} catch (const SMFReader::UnsupportedTime& err) {
+			} catch (const Evoral::SMFReader::UnsupportedTime& err) {
 				error << _("Import: unsupported MIDI time stamp format") << endmsg;
 				status.done = status.cancel = true;
 				return;
diff --git a/libs/ardour/midi_source.cc b/libs/ardour/midi_source.cc
index d6d27a1f89..ac52b81ee5 100644
--- a/libs/ardour/midi_source.cc
+++ b/libs/ardour/midi_source.cc
@@ -165,8 +165,7 @@ MidiSource::mark_streaming_write_completed ()
 void
 MidiSource::session_saved()
 {
-	flush_header();
-	flush_footer();
+	flush_midi();
 
 	if (_model && _model->edited()) {
 		string newname;
@@ -197,8 +196,7 @@ MidiSource::session_saved()
 		newsrc->set_model(_model);
 		_model->set_midi_source(newsrc.get());
 		
-		newsrc->flush_header();
-		newsrc->flush_footer();
+		newsrc->flush_midi();
 
 		Switched.emit(newsrc);
 	}
diff --git a/libs/ardour/smf_reader.cc b/libs/ardour/smf_reader.cc
deleted file mode 100644
index 48ec3dc386..0000000000
--- a/libs/ardour/smf_reader.cc
+++ /dev/null
@@ -1,285 +0,0 @@
-/*
-    Copyright (C) 2008 Paul Davis 
-    Written by Dave Robillard
-
-    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., 675 Mass Ave, Cambridge, MA 02139, USA.
-*/
-
-#include <cstring>
-#include <cstdio>
-#include <cassert>
-#include <iostream>
-#include <glibmm/miscutils.h>
-#include <midi++/events.h>
-
-#include <ardour/smf_reader.h>
-#include <ardour/midi_util.h>
-
-using namespace std;
-
-namespace ARDOUR {
-
-
-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) + 1;
-		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 ARDOUR
-
diff --git a/libs/ardour/smf_source.cc b/libs/ardour/smf_source.cc
index 3bd929d2ca..5b70f8e9c6 100644
--- a/libs/ardour/smf_source.cc
+++ b/libs/ardour/smf_source.cc
@@ -32,13 +32,14 @@
 
 #include <glibmm/miscutils.h>
 
+#include <evoral/SMFReader.hpp>
+
 #include <ardour/smf_source.h>
 #include <ardour/session.h>
 #include <ardour/midi_ring_buffer.h>
 #include <ardour/midi_util.h>
 #include <ardour/tempo.h>
 #include <ardour/audioengine.h>
-#include <ardour/smf_reader.h>
 #include <ardour/event_type_map.h>
 
 #include "i18n.h"
@@ -54,13 +55,9 @@ uint64_t                              SMFSource::header_position_offset;
 
 SMFSource::SMFSource (Session& s, std::string path, Flag flags)
 	: MidiSource (s, region_name_from_path(path, false))
+	, SMF ()
 	, _flags (Flag(flags | Writable)) // FIXME: this needs to be writable for now
 	, _allow_remove_if_empty(true)
-	, _fd (0)
-	, _last_ev_time(0)
-	, _track_size(4) // 4 bytes for the ever-present EOT event
-	, _header_size(22)
-	, _empty(true)
 {
 	/* constructor used for new internal-to-session files. file cannot exist */
 
@@ -68,7 +65,7 @@ SMFSource::SMFSource (Session& s, std::string path, Flag flags)
 		throw failed_constructor ();
 	}
 	
-	if (open()) {
+	if (open(path)) {
 		throw failed_constructor ();
 	}
 
@@ -79,11 +76,6 @@ SMFSource::SMFSource (Session& s, const XMLNode& node)
 	: MidiSource (s, node)
 	, _flags (Flag (Writable|CanRename))
 	, _allow_remove_if_empty(true)
-	, _fd (0)
-	, _last_ev_time(0)
-	, _track_size(4) // 4 bytes for the ever-present EOT event
-	, _header_size(22)
-	, _empty(true)
 {
 	/* constructor used for existing internal-to-session files. file must exist */
 
@@ -95,7 +87,7 @@ SMFSource::SMFSource (Session& s, const XMLNode& node)
 		throw failed_constructor ();
 	}
 	
-	if (open()) {
+	if (open(_path)) {
 		throw failed_constructor ();
 	}
 	
@@ -134,245 +126,6 @@ SMFSource::init (string pathstr, bool must_exist)
 	return 0;
 }
 
-/** Attempt to open the SMF file for reading and writing.
- *
- * Currently SMFSource is always read/write.
- *
- * \return  0 on success
- *         -1 if the file can not be opened for reading,
- *         -2 if the file can not be opened for writing
- */
-int
-SMFSource::open()
-{
-	//cerr << "Opening SMF file " << path() << " writeable: " << writable() << endl;
-
-	assert(writable()); // FIXME;
-
-	_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;
-}
-
-void
-SMFSource::close()
-{
-	if (_fd) {
-		flush_header();
-		flush_footer();
-		fclose(_fd);
-		_fd = NULL;
-	}
-}
-
-void
-SMFSource::seek_to_footer_position()
-{
-	uint8_t buffer[4];
-	
-	// lets check if there is a track end marker at the end of the data
-	fseek(_fd, -4, SEEK_END);
-	//cerr << "SMFSource::seek_to_footer_position: At position: " << ftell(_fd);
-	size_t read_bytes = fread(buffer, sizeof(uint8_t), 4, _fd);
-	/*cerr << " read size: " << read_bytes << " buffer: ";
-	for (size_t i=0; i < read_bytes; ++i) {
-		printf("%x ", buffer[i]);
-	}
-	printf("\n");
-	*/
-	
-	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);
-	}
-}
-
-int
-SMFSource::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;
-}
-
-int
-SMFSource::flush_footer()
-{
-	//cerr << path() << " SMF Flushing footer\n";
-	seek_to_footer_position();
-	write_footer();
-	seek_to_footer_position();
-
-	return 0;
-}
-
-void
-SMFSource::write_footer()
-{
-	write_var_len(0);
-	char eot[3] = { 0xFF, 0x2F, 0x00 }; // end-of-track meta-event
-	fwrite(eot, 1, 3, _fd);
-	fflush(_fd);
-}
-
-/** Returns the offset of the first event in the file with a time past @a start,
- * relative to the start of the source.
- *
- * Returns -1 if not found.
- */
-/*
-long
-SMFSource::find_first_event_after(nframes_t start)
-{
-	// FIXME: obviously this is slooow
-	
-	fseek(_fd, _header_size, 0);
-
-	while ( ! feof(_fd) ) {
-		const uint32_t delta_time = read_var_len();
-
-		if (delta_time > start)
-			return delta_time;
-	}
-
-	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, in SMF tempo-based ticks, using the
- * rate given by ppqn() (it is the caller's responsibility to calculate a real time).
- *
- * \a size should be the capacity of \a buf.  If it is not large enough, \a buf will
- * be freed and a new buffer allocated in its place, the size of which will be placed
- * in size.
- *
- * 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).
- */
-int
-SMFSource::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;
-		}
-	}
-	
-	const int event_size = midi_event_size((unsigned char)status) + 1;
-	if (event_size <= 0) {
-		*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("SMFSource %s read event: delta = %u, size = %u, data = ", _name.c_str(), *delta_t, *size);
-	for (size_t i=0; i < *size; ++i) {
-		printf("%X ", (*buf)[i]);
-	}
-	printf("\n");*/
-	
-	return (int)*size;
-}
-
 /** All stamps in audio frames */
 nframes_t
 SMFSource::read_unlocked (MidiRingBuffer& dst, nframes_t start, nframes_t cnt, nframes_t stamp_offset, nframes_t negative_stamp_offset) const
@@ -393,16 +146,16 @@ SMFSource::read_unlocked (MidiRingBuffer& dst, nframes_t start, nframes_t cnt, n
 	size_t scratch_size = 0; // keep track of scratch to minimize reallocs
 
 	// FIXME: don't seek to start and search every read (brutal!)
-	fseek(_fd, _header_size, SEEK_SET);
+	SMF::seek_to_start();
 	
 	// FIXME: assumes tempo never changes after start
 	const double frames_per_beat = _session.tempo_map().tempo_at(_timeline_position).frames_per_beat(
 			_session.engine().frame_rate(),
 			_session.tempo_map().meter_at(_timeline_position));
 	
-	const uint64_t start_ticks = (uint64_t)((start / frames_per_beat) * _ppqn);
+	const uint64_t start_ticks = (uint64_t)((start / frames_per_beat) * ppqn());
 
-	while (!feof(_fd)) {
+	while (!SMF::eof()) {
 		int ret = read_event(&ev_delta_t, &ev_size, &ev_buffer);
 		if (ret == -1) { // EOF
 			//cerr << "SMF - EOF\n";
@@ -420,7 +173,7 @@ SMFSource::read_unlocked (MidiRingBuffer& dst, nframes_t start, nframes_t cnt, n
 
 		if (time >= start_ticks) {
 			const nframes_t ev_frame_time = (nframes_t)(
-					((time / (double)_ppqn) * frames_per_beat)) + stamp_offset;
+					((time / (double)ppqn()) * frames_per_beat)) + stamp_offset;
 
 			if (ev_frame_time <= start + cnt)
 				dst.write(ev_frame_time - negative_stamp_offset, ev_type, ev_size, ev_buffer);
@@ -493,7 +246,7 @@ SMFSource::write_unlocked (MidiRingBuffer& src, nframes_t cnt)
 			_model->append(ev);
 	}
 
-	fflush(_fd);
+	SMF::flush();
 	free(buf);
 
 	const nframes_t oldlen = _length;
@@ -520,8 +273,8 @@ SMFSource::append_event_unlocked(EventTimeUnit unit, const Evoral::Event& ev)
 	
 	assert(ev.time() >= 0);
 	
-	if (ev.time() < _last_ev_time) {
-		cerr << "SMFSource: Warning: Skipping event with ev.time() < _last_ev_time" << endl;
+	if (ev.time() < last_event_time()) {
+		cerr << "SMFSource: Warning: Skipping event with ev.time() < last.time()" << endl;
 		return;
 	}
 	
@@ -533,22 +286,15 @@ SMFSource::append_event_unlocked(EventTimeUnit unit, const Evoral::Event& ev)
 				_session.engine().frame_rate(),
 				_session.tempo_map().meter_at(_timeline_position));
 
-		delta_time = (uint32_t)((ev.time() - _last_ev_time) / frames_per_beat * _ppqn);
+		delta_time = (uint32_t)((ev.time() - last_event_time()) / frames_per_beat * ppqn());
 	} else {
 		assert(unit == Beats);
-		delta_time = (uint32_t)((ev.time() - _last_ev_time) * _ppqn);
+		delta_time = (uint32_t)((ev.time() - last_event_time()) * ppqn());
 	}
 
-	
-	const size_t stamp_size = write_var_len(delta_time);
-	fwrite(ev.buffer(), 1, ev.size(), _fd);
+	SMF::append_event_unlocked(delta_time, ev);
 
-	_track_size += stamp_size + ev.size();
 	_write_data_count += ev.size();
-	_last_ev_time = ev.time();
-
-	if (ev.size() > 0)
-		_empty = false;
 }
 
 
@@ -601,8 +347,7 @@ void
 SMFSource::mark_streaming_midi_write_started (NoteMode mode, nframes_t start_frame)
 {
 	MidiSource::mark_streaming_midi_write_started (mode, start_frame);
-	_last_ev_time = 0;
-	fseek(_fd, _header_size, SEEK_SET);
+	SMF::begin_write (start_frame);
 }
 
 void
@@ -615,8 +360,7 @@ SMFSource::mark_streaming_write_completed ()
 	}
 	
 	_model->set_edited(false);
-	flush_header();
-	flush_footer();
+	SMF::end_write ();
 }
 
 void
@@ -855,56 +599,6 @@ SMFSource::set_source_name (string newname, bool destructive)
 	return 0;//rename_peakfile (peak_path (_path));
 }
 
-bool
-SMFSource::is_empty () const
-{
-	return _empty;
-}
-
-
-void
-SMFSource::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);
-}
-
-void
-SMFSource::write_chunk(const char id[4], uint32_t length, void* data)
-{
-	write_chunk_header(id, length);
-	
-	fwrite(data, 1, length, _fd);
-}
-
-/** Returns the size (in bytes) of the value written. */
-size_t
-SMFSource::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;
-}
-
 void
 SMFSource::load_model(bool lock, bool force_reload)
 {
@@ -927,8 +621,7 @@ SMFSource::load_model(bool lock, bool force_reload)
 	}
 
 	_model->start_write();
-
-	fseek(_fd, _header_size, SEEK_SET);
+	SMF::seek_to_start();
 
 	uint64_t time = 0; /* in SMF ticks */
 	Evoral::Event ev;
@@ -951,7 +644,7 @@ SMFSource::load_model(bool lock, bool force_reload)
 		
 		if (ret > 0) { // didn't skip (meta) event
 			// make ev.time absolute time in frames
-			ev.time() = time * frames_per_beat / (EventTime)_ppqn;
+			ev.time() = time * frames_per_beat / (EventTime)ppqn();
 			ev.set_event_type(EventTypeMap::instance().midi_event_type(buf[0]));
 			_model->append(ev);
 		}
@@ -976,3 +669,9 @@ SMFSource::destroy_model()
 	_model.reset();
 }
 
+void
+SMFSource::flush_midi()
+{
+	SMF::end_write();
+}
+