audioEnvelope.cpp: check for division by zero

[kdenlive] / src / lib / audio / audioEnvelope.cpp

diff --git a/src/lib/audio/audioEnvelope.cpp b/src/lib/audio/audioEnvelope.cpp
index 7849372d1a5ce067d715d3a0dcfd59d1a297a3c7..d47695933f27ae096db05c464ee61b875240018b 100644 (file)
--- a/src/lib/audio/audioEnvelope.cpp
+++ b/src/lib/audio/audioEnvelope.cpp
@@ -16,14 +16,26 @@
 #include <cmath>
 #include <iostream>
 
-AudioEnvelope::AudioEnvelope(Mlt::Producer *producer) :
+AudioEnvelope::AudioEnvelope(Mlt::Producer *producer, int offset, int length) :
     m_envelope(NULL),
-    m_producer(producer),
+    m_offset(offset),
+    m_length(length),
     m_envelopeSize(producer->get_length()),
+    m_envelopeMax(0),
+    m_envelopeMean(0),
+    m_envelopeStdDev(0),
     m_envelopeStdDevCalculated(false),
     m_envelopeIsNormalized(false)
 {
+    // make a copy of the producer to avoid audio playback issues
+    m_producer = new Mlt::Producer(*(producer->profile()), producer->get("resource"));
     m_info = new AudioInfo(m_producer);
+
+    Q_ASSERT(m_offset >= 0);
+    if (m_length > 0) {
+        Q_ASSERT(m_length+m_offset <= m_envelopeSize);
+        m_envelopeSize = m_length;
+    }
 }
 
 AudioEnvelope::~AudioEnvelope()
@@ -32,6 +44,7 @@ AudioEnvelope::~AudioEnvelope()
         delete[] m_envelope;
     }
     delete m_info;
+    delete m_producer;
 }
 
 
@@ -47,6 +60,10 @@ int AudioEnvelope::envelopeSize() const
 {
     return m_envelopeSize;
 }
+int64_t AudioEnvelope::maxValue() const
+{
+    return m_envelopeMax;
+}
 
 
 
@@ -71,7 +88,8 @@ void AudioEnvelope::loadEnvelope()
 
     QTime t;
     t.start();
-    m_producer->seek(0);
+    int count = 0;
+    m_producer->seek(m_offset);
     m_producer->set_speed(1.0); // This is necessary, otherwise we don't get any new frames in the 2nd run.
     for (int i = 0; i < m_envelopeSize; i++) {
 
@@ -96,6 +114,11 @@ void AudioEnvelope::loadEnvelope()
 //                  << "-" << m_producer->get_in() << "+" << m_producer->get_out() << " ";
 
         delete frame;
+
+        count++;
+        if (m_length > 0 && count > m_length) {
+            break;
+        }
     }
     m_envelopeMean /= m_envelopeSize;
     std::cout << "Calculating the envelope (" << m_envelopeSize << " frames) took "
@@ -161,6 +184,10 @@ QImage AudioEnvelope::drawEnvelope()
 
     QImage img(m_envelopeSize, 400, QImage::Format_ARGB32);
     img.fill(qRgb(255,255,255));
+
+    if (m_envelopeMax == 0)
+        return img;
+
     double fy;
     for (int x = 0; x < img.width(); x++) {
         fy = m_envelope[x]/double(m_envelopeMax) * img.height();