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livetrax/libs/evoral/src/SMF.cpp
David Robillard 550613a898 verbosity--
git-svn-id: svn://localhost/ardour2/branches/3.0@4536 d708f5d6-7413-0410-9779-e7cbd77b26cf
2009-02-11 20:47:40 +00:00

370 lines
8.0 KiB
C++

/* This file is part of Evoral.
* Copyright (C) 2008 Dave 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/SMF.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()
{
}
/** Attempt to open the SMF file for reading and writing.
*
* Currently SMF 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
*/
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);
}
/** 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).
*/
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() throw(typename MIDIFile<Time>::FileError)
{
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);
}
/** Returns the size (in bytes) of the value written. */
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<double>;
} // namespace Evoral