qsui: added waveform seekbar optimization (Linearithmik, #1086)

git-svn-id: http://svn.code.sf.net/p/qmmp-dev/code/trunk/qmmp@10151 90c681e8-e032-0410-971d-27865f9a5e38

1 files changed, 13 insertions, 9 deletions

diff --git a/src/plugins/Ui/qsui/qsuiwaveformseekbar.cpp b/src/plugins/Ui/qsui/qsuiwaveformseekbar.cpp
index 59f05c206..f098c729a 100644
--- a/src/plugins/Ui/qsui/qsuiwaveformseekbar.cpp
+++ b/src/plugins/Ui/qsui/qsuiwaveformseekbar.cpp
@@ -448,26 +448,30 @@ void QSUiWaveformScanner::run()
     float *rms = new float[m_ap.channels()]{ 0 };
     int counter = 0;
     int channels = m_ap.channels();
+    float value = 0.f;
     while (!m_user_stop)
     {
         m_mutex.unlock();
         qint64 len = m_decoder->read(tmp, sizeof(tmp));
         if(len > 0)
         {
-            converter.toFloat(tmp, out, len / m_ap.sampleSize());
+            auto sample_count = len / m_ap.sampleSize();
+            converter.toFloat(tmp, out, sample_count);
 
-            for(uint sample = 0; sample < len / m_ap.sampleSize(); sample++)
+            for(uint sample = 0; sample < sample_count - channels; sample += channels)
             {
-                int ch = sample % channels;
-                min[ch] = qMin(min[ch], out[sample]);
-                max[ch] = qMax(max[ch], out[sample]);
-                rms[ch] += (out[sample] * out[sample]);
-
-                counter++;
+                for(int ch = 0; ch < channels; ++ch)
+                {
+                    value = out[sample + ch];
+                    min[ch] = qMin(min[ch], value);
+                    max[ch] = qMax(max[ch], value);
+                    rms[ch] += (value * value);
+                }
+                counter += channels;
                 if(counter >= samplesPerValue)
                 {
                     m_mutex.lock();
-                    for(ch = 0; ch < channels; ++ch)
+                    for(int ch = 0; ch < channels; ++ch)
                     {
                         m_data << max[ch] * 1000;
                         m_data << min[ch] * 1000;