Demo Spectrum wav data size is not calculated correctly

- Grab length of audio data from Data chunk size
- Read from the device no greater than the audio Data chunk size

Task-number: QTBUG-13779
Reviewed-by: Andrew den Exter

1 files changed, 1 insertions, 0 deletions

diff --git a/demos/spectrum/app/wavfile.h b/demos/spectrum/app/wavfile.h
index f2f3304..fc14b08 100644
--- a/demos/spectrum/app/wavfile.h
+++ b/demos/spectrum/app/wavfile.h
@@ -77,6 +77,7 @@ public:
 private:
     QAudioFormat m_format;
     qint64 m_dataLength;
+    qint64 m_dataPosition;
 };
 
 #endif