Merge lp:~mixxxdevelopers/mixxx/features_trackbeats into lp:~mixxxdevelopers/mixxx/trunk

[Phillip Whelan]

Merging from TrackBeats; use sample offsets at runtime.

Use sample offsets in the Beats objects. This way it fits in with the rest of the codebase.

[lp:~mixxxdevelopers/mixxx/features_trackbeats]

2563. By Phillip Whelan on 2011-03-09

Comments for beatgrid units, contributed by Albert Santoni.

2564. By Phillip Whelan on 2011-03-09

Change beatgrid to serialize in frame offsets but use sample offsets at runtime.

2565. By Phillip Whelan on 2011-03-10

Cleaning up some cruft left over from earlier shift to using sample offsets at runtime.

[Albert Santoni (gamegod)]

Everything looks great to me now, Phil!

Good stuff!

review: Approve

=== modified file 'mixxx/src/track/beatgrid.cpp'
--- mixxx/src/track/beatgrid.cpp	2011-03-07 00:20:41 +0000
+++ mixxx/src/track/beatgrid.cpp	2011-03-10 02:59:24 +0000
@@ -4,6 +4,8 @@
 #include "track/beatgrid.h"
 
 
+static int kFrameSize = 2;
+
 struct BeatGridData {
 	double bpm;
 	double firstBeat;
@@ -33,12 +35,13 @@
     QMutexLocker lock(&m_mutex);
     m_dBpm = dBpm;
     m_dFirstBeat = dFirstBeatSample;
-    m_dBeatLength = 60.0 * m_iSampleRate / m_dBpm;
+    // Calculate beat length as sample offsets
+    m_dBeatLength = (60.0 * m_iSampleRate / m_dBpm) * kFrameSize;
 }
 
 QByteArray* BeatGrid::toByteArray() const {
     QMutexLocker locker(&m_mutex);
-    BeatGridData blob = { m_dBpm, m_dFirstBeat };
+    BeatGridData blob = { (m_dBpm / kFrameSize), (m_dFirstBeat / kFrameSize) };
     QByteArray* pByteArray = new QByteArray((char *)&blob, sizeof(blob));
     return pByteArray;
 }
@@ -47,7 +50,8 @@
     if ( pByteArray->size() != sizeof(BeatGridData))
         return;
     BeatGridData *blob = (BeatGridData *)pByteArray->data();
-    setGrid(blob->bpm, blob->firstBeat);
+    // We serialize into frame offsets but use sample offsets at runtime
+    setGrid(blob->bpm, blob->firstBeat * kFrameSize);
 }
 
 QString BeatGrid::getVersion() const {

=== modified file 'mixxx/src/track/beatgrid.h'
--- mixxx/src/track/beatgrid.h	2011-03-03 02:38:29 +0000
+++ mixxx/src/track/beatgrid.h	2011-03-10 02:59:24 +0000
@@ -66,9 +66,10 @@
     bool isValid() const;
 
     mutable QMutex m_mutex;
-    int m_iSampleRate;
-    double m_dBpm, m_dFirstBeat;
-    double m_dBeatLength;
+    int m_iSampleRate;      /** The number of samples per second */
+    double m_dBpm;          /** The number of beats per minute */
+    double m_dFirstBeat;    /** The sample offset of the first beat */
+    double m_dBeatLength;   /** The length of a beat in samples */
 };
 
 

=== modified file 'mixxx/src/track/beatmatrix.cpp'
--- mixxx/src/track/beatmatrix.cpp	2011-03-03 02:38:29 +0000
+++ mixxx/src/track/beatmatrix.cpp	2011-03-10 02:59:24 +0000
@@ -76,6 +76,8 @@
 
 double BeatMatrix::findNthBeat(double dSamples, int n) const {
     QMutexLocker locker(&m_mutex);
+    // Reduce the Sample Offset to a frame offset.
+    dSamples = floorf(dSamples/2);
     BeatList::const_iterator it;
     int i;
 
@@ -89,7 +91,8 @@
         // Count down until n=1
         while (it != m_beatList.end()) {
             if (n == 1) {
-                return *it;
+                // Return a Sample Offset
+                return (*it * 2);
             }
             it++; n--;
         }
@@ -106,7 +109,8 @@
             // not put us before the start of the loop.
             it--;
             if (n == -1) {
-                return *it;
+                // Return a Sample Offset
+                return (*it * 2);
             }
             n++;
         }

=== modified file 'mixxx/src/waveform/waveformrenderbeat.cpp'
--- mixxx/src/waveform/waveformrenderbeat.cpp	2011-02-26 07:08:21 +0000
+++ mixxx/src/waveform/waveformrenderbeat.cpp	2011-03-10 02:59:24 +0000
@@ -100,7 +100,6 @@
         return;
 
     int iCurPos = (int)(dPlayPos * m_iNumSamples);
-
     if(iCurPos % 2 != 0)
         iCurPos--;
 
@@ -127,12 +126,9 @@
     double halfw = m_iWidth/2;
     double halfh = m_iHeight/2;
 
-    // NOTE: converting curpos from stereo samples to mono samples
-    iCurPos = iCurPos >> 1;
-
     // basePos and endPos are in samples
-    double basePos = iCurPos - m_dSamplesPerPixel*halfw*(1.0+rateAdjust);
-    double endPos = basePos + m_iWidth*m_dSamplesPerPixel*(1.0+rateAdjust);
+    double basePos = iCurPos - m_dSamplesPerPixel * m_iWidth * (1.0+rateAdjust);
+    double endPos = basePos + (2 * m_iWidth) * m_dSamplesPerPixel * (1.0+rateAdjust);
 
 
     m_beatList.clear();
@@ -144,7 +140,7 @@
             continue;
 
         // i relative to the current play position in subpixels
-        double i = (curPos - iCurPos)/m_dSamplesPerDownsample;
+        double i = (((curPos) - iCurPos)/2)/m_dSamplesPerDownsample;
 
         // If i is less than 20 subpixels from center, highlight it.
         if(abs(i) < 20) {