[Performous-commit] Tapio Vierros : Magic time stamp rounding error compensator for SS XML writer.

[Tapio V. <aa...@us...>]

Module: editor
Branch: master
Commit: 56e87680ef773cda9a606741dd1331383e1c494d

Author: Tapio Vierros <tap...@gm...>
Date:   Tue Jan 25 15:28:11 2011 +0200

Magic time stamp rounding error compensator for SS XML writer.

Now very good sync.

---

 songwriter-xml.cc |   22 +++++++++++++++-------
 songwriter.hh     |    1 +
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/songwriter-xml.cc b/songwriter-xml.cc
index e370e8f..456963e 100644
--- a/songwriter-xml.cc
+++ b/songwriter-xml.cc
@@ -21,26 +21,30 @@ void SingStarXMLWriter::writeXML() {
 	root.setAttribute("audioVersion", "2"); //?
 	doc.appendChild(root);
 
+	// Some helpful comments
 	QDomComment artistComment = doc.createComment(QString("Artist: ") + s.artist);
 	QDomComment titleComment = doc.createComment(QString("Title: ") + s.title);
 	root.appendChild(artistComment);
 	root.appendChild(titleComment);
 
+	// Track element
 	int tracknum = 1;
 	QDomElement trackElem = doc.createElement("TRACK");
 	trackElem.setAttribute("Name", "Player1");
 	trackElem.setAttribute("Artist", s.artist);
 	root.appendChild(trackElem);
 
+	// Create first sentence
 	int sentencenum = 1;
 	QDomElement sentenceElem = doc.createElement("SENTENCE"); // FIXME: Should there be Singer and Part attributes?
 	QDomComment sentenceComment = doc.createComment(QString("Track %1, Sentence %2").arg(tracknum).arg(sentencenum));
 	sentenceElem.appendChild(sentenceComment);
 	// First sentence also needs a starting SLEEP
 	Notes const& notes = s.getVocalTrack().notes;
+	int ts = sec2dur(notes.front().begin);
 	QDomElement firstNoteElem = doc.createElement("NOTE");
 	firstNoteElem.setAttribute("MidiNote", "0");
-	firstNoteElem.setAttribute("Duration", QString::number(sec2dur(notes.front().begin)));
+	firstNoteElem.setAttribute("Duration", QString::number(ts));
 	firstNoteElem.setAttribute("Lyric", "");
 	sentenceElem.appendChild(firstNoteElem);
 
@@ -59,9 +63,10 @@ void SingStarXMLWriter::writeXML() {
 		} else { // Regular note handling
 
 			// Construct the note element
+			int l = sec2dur(n.length()); ts += l;
 			QDomElement noteElem = doc.createElement("NOTE");
 			noteElem.setAttribute("MidiNote", QString::number(n.note));
-			noteElem.setAttribute("Duration", QString::number(sec2dur(n.length())));
+			noteElem.setAttribute("Duration", QString::number(l));
 			noteElem.setAttribute("Lyric", n.syllable);
 			if (n.type == Note::GOLDEN) noteElem.setAttribute("Bonus", "Yes");
 			if (n.type == Note::FREESTYLE) noteElem.setAttribute("FreeStyle", "Yes");
@@ -70,22 +75,21 @@ void SingStarXMLWriter::writeXML() {
 
 		// Construct a note element, indicationg the pause before next note
 		// This is only done if the pause has duration
+		// We also take the overall position into consideration (counter rounding errors)
 		int pauseLen = 0;
+		double end = dur2sec(ts) + n.length();
 		if (i < notes.size() - 1)
-			pauseLen = sec2dur(notes[i+1].begin - n.end); // Difference to next note
+			pauseLen = sec2dur(notes[i+1].begin - end); // Difference to next note
 		if (pauseLen > 0) {
 			QDomElement pauseElem = doc.createElement("NOTE");
 			pauseElem.setAttribute("MidiNote", "0");
 			pauseElem.setAttribute("Duration", QString::number(pauseLen));
 			pauseElem.setAttribute("Lyric", "");
 			sentenceElem.appendChild(pauseElem);
+			ts += pauseLen;
 		}
 	}
 
-	// TODO: Needs a last dummy sentence
-
-	//root.appendChild(sentenceElem);
-
 	// Get the xml data
 	QString xml = doc.toString(4);
 	// Write to file
@@ -99,3 +103,7 @@ void SingStarXMLWriter::writeXML() {
 int SingStarXMLWriter::sec2dur(double sec) {
 	return round(tempo / 60.0 * sec * 8); // 8 for Demisemiquaver
 }
+
+double SingStarXMLWriter::dur2sec(int ts) {
+	return ts * 60.0 / (tempo * 8); // 8 for Demisemiquaver
+}
diff --git a/songwriter.hh b/songwriter.hh
index 13016fb..fe21997 100644
--- a/songwriter.hh
+++ b/songwriter.hh
@@ -17,6 +17,7 @@ struct SingStarXMLWriter: public SongWriter
 private:
 	void writeXML();
 	int sec2dur(double sec);
+	double dur2sec(int ts);
 	int tempo;
 };