C++ Alg_seq_ptr::convert_to_beats方法代码示例

bool Alg_midifile_reader::parse()
{
    channel_offset = 0;
    seq->convert_to_beats();
    midifile();
    seq->set_real_dur(seq->get_time_map()->beat_to_time(seq->get_beat_dur()));
    return midifile_error != 0;
}

Alg_seq_ptr NoteTrack::MakeExportableSeq()
{
   double offset = GetOffset();
   if (offset == 0)
      return mSeq;
   // make a copy, deleting events that are shifted before time 0
   double start = -offset;
   if (start < 0) start = 0;
   // notes that begin before "start" are not included even if they
   // extend past "start" (because "all" parameter is set to false)
   Alg_seq_ptr seq = mSeq->copy(start, mSeq->get_dur() - start, false);
   if (offset > 0) {
      // swap seq and mSeq so that Shift operates on the new copy
      Alg_seq_ptr old_seq = mSeq;
      mSeq = seq;
      Shift(offset);
      seq = mSeq;  // undo the swap
      mSeq = old_seq;
#ifdef OLD_CODE
      // now shift events by offset. This must be done with an integer
      // number of measures, so first, find the beats-per-measure
      double beats_per_measure = 4.0;
      Alg_time_sig_ptr tsp = NULL;
      if (seq->time_sig.length() > 0 && seq->time_sig[0].beat < ALG_EPS) {
         // there is an initial time signature
         tsp = &(seq->time_sig[0]);
         beats_per_measure = (tsp->num * 4) / tsp->den;
      }
      // also need the initial tempo
      double bps = ALG_DEFAULT_BPM / 60;
      Alg_time_map_ptr map = seq->get_time_map();
      Alg_beat_ptr bp = &(map->beats[0]);
      if (bp->time < ALG_EPS) { // tempo change at time 0
         if (map->beats.len > 1) { // compute slope to get tempo
            bps = (map->beats[1].beat - map->beats[0].beat) /
                  (map->beats[1].time - map->beats[0].time);
         } else if (seq->get_time_map()->last_tempo_flag) {
            bps = seq->get_time_map()->last_tempo;
         }
      }
      // find closest number of measures to fit in the gap
      // number of measures is offset / measure_time
      double measure_time = beats_per_measure / bps; // seconds per measure
      int n = ROUND(offset / measure_time);
      if (n == 0) n = 1;
      // we will insert n measures. Compute the desired duration of each.
      measure_time = offset / n;
      bps = beats_per_measure / measure_time;
      // insert integer multiple of measures at beginning
      seq->convert_to_beats();
      seq->insert_silence(0, beats_per_measure * n);
      // make sure time signature at 0 is correct
      if (tsp) {
         seq->set_time_sig(0, tsp->num, tsp->den);
      }
      // adjust tempo to match offset
      seq->set_tempo(bps * 60.0, 0, beats_per_measure * n);
#endif
   } else {
      // if offset is negative, it might not be a multiple of beats, but
      // we want to preserve the relative positions of measures. I.e. we
      // should shift barlines and time signatures as well as notes.
      // Insert a time signature at the first bar-line if necessary.

      // Translate start from seconds to beats and call it beat:
      double beat = mSeq->get_time_map()->time_to_beat(start);
      // Find the time signature in mSeq in effect at start (beat):
      int i = mSeq->time_sig.find_beat(beat);
      // i is where you would insert a new time sig at beat,
      // Case 1: beat coincides with a time sig at i. Time signature
      // at beat means that there is a barline at beat, so when beat
      // is shifted to 0, the relative barline positions are preserved
      if (mSeq->time_sig.length() > 0 &&
          within(beat, mSeq->time_sig[i].beat, ALG_EPS)) {
         // beat coincides with time signature change, so offset must
         // be a multiple of beats
         /* do nothing */ ;
      // Case 2: there is no time signature before beat.
      } else if (i == 0 && (mSeq->time_sig.length() == 0 ||
                            mSeq->time_sig[i].beat > beat)) {
         // If beat does not fall on an implied barline, we need to
         // insert a time signature.
         double measures = beat / 4.0;
         double imeasures = ROUND(measures);
         if (!within(measures, imeasures, ALG_EPS)) {
            double bar_offset = (int(measures) + 1) * 4.0 - beat;
            seq->set_time_sig(bar_offset, 4, 4);
         }
      // This case should never be true because if i == 0, either there
      // are no time signatures before beat (Case 2),
      // or there is one time signature at beat (Case 1)
      } else if (i == 0) {
         /* do nothing (might be good to assert(false)) */ ;
      // Case 3: i-1 must be the effective time sig position
      } else {
         i -= 1; // index the time signature in effect at beat
         Alg_time_sig_ptr tsp = &(mSeq->time_sig[i]);
         double beats_per_measure = (tsp->num * 4) / tsp->den;
         double measures = (beat - tsp->beat) / beats_per_measure;
         int imeasures = ROUND(measures);
//.........这里部分代码省略.........

bool MidiImport::readSMF( TrackContainer* tc )
{
	QString filename = file().fileName();
	closeFile();

	const int preTrackSteps = 2;
	QProgressDialog pd( TrackContainer::tr( "Importing MIDI-file..." ),
	TrackContainer::tr( "Cancel" ), 0, preTrackSteps, gui->mainWindow() );
	pd.setWindowTitle( TrackContainer::tr( "Please wait..." ) );
	pd.setWindowModality(Qt::WindowModal);
	pd.setMinimumDuration( 0 );

	pd.setValue( 0 );

	Alg_seq_ptr seq = new Alg_seq(filename.toLocal8Bit(), true);
	seq->convert_to_beats();

	pd.setMaximum( seq->tracks()  + preTrackSteps );
	pd.setValue( 1 );
	
	// 128 CC + Pitch Bend
	smfMidiCC ccs[129];
	smfMidiChannel chs[256];

	MeterModel & timeSigMM = Engine::getSong()->getTimeSigModel();
	AutomationPattern * timeSigNumeratorPat = 
		AutomationPattern::globalAutomationPattern( &timeSigMM.numeratorModel() );
	AutomationPattern * timeSigDenominatorPat = 
		AutomationPattern::globalAutomationPattern( &timeSigMM.denominatorModel() );
	
	// TODO: adjust these to Time.Sig changes
	double beatsPerTact = 4; 
	double ticksPerBeat = DefaultTicksPerTact / beatsPerTact;

	// Time-sig changes
	Alg_time_sigs * timeSigs = &seq->time_sig;
	for( int s = 0; s < timeSigs->length(); ++s )
	{
		Alg_time_sig timeSig = (*timeSigs)[s];
		// Initial timeSig, set song-default value
		if(/* timeSig.beat == 0*/ true )
		{
			// TODO set song-global default value
			printf("Another timesig at %f\n", timeSig.beat);
			timeSigNumeratorPat->putValue( timeSig.beat*ticksPerBeat, timeSig.num );
			timeSigDenominatorPat->putValue( timeSig.beat*ticksPerBeat, timeSig.den );
		}
		else
		{
		}

	}

	pd.setValue( 2 );

	// Tempo stuff
	AutomationPattern * tap = tc->tempoAutomationPattern();
	if( tap )
	{
		tap->clear();
		Alg_time_map * timeMap = seq->get_time_map();
		Alg_beats & beats = timeMap->beats;
		for( int i = 0; i < beats.len - 1; i++ )
		{
			Alg_beat_ptr b = &(beats[i]);
			double tempo = ( beats[i + 1].beat - b->beat ) /
						   ( beats[i + 1].time - beats[i].time );
			tap->putValue( b->beat * ticksPerBeat, tempo * 60.0 );
		}
		if( timeMap->last_tempo_flag )
		{
			Alg_beat_ptr b = &( beats[beats.len - 1] );
			tap->putValue( b->beat * ticksPerBeat, timeMap->last_tempo * 60.0 );
		}
	}

	// Song events
	for( int e = 0; e < seq->length(); ++e )
	{
		Alg_event_ptr evt = (*seq)[e];

		if( evt->is_update() )
		{
			printf("Unhandled SONG update: %d %f %s\n", 
					evt->get_type_code(), evt->time, evt->get_attribute() );
		}
	}

	// Tracks
	for( int t = 0; t < seq->tracks(); ++t )
	{
		QString trackName = QString( tr( "Track" ) + " %1" ).arg( t );
		Alg_track_ptr trk = seq->track( t );
		pd.setValue( t + preTrackSteps );

		for( int c = 0; c < 129; c++ )
		{
			ccs[c].clear();
		}

//.........这里部分代码省略.........