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-rw-r--r--doc/src/demos/spectrum.qdoc34
-rw-r--r--doc/src/getting-started/demos.qdoc9
-rw-r--r--doc/src/images/spectrum-demo.pngbin0 -> 21771 bytes
3 files changed, 39 insertions, 4 deletions
diff --git a/doc/src/demos/spectrum.qdoc b/doc/src/demos/spectrum.qdoc
index b720ce1..d5a3f85 100644
--- a/doc/src/demos/spectrum.qdoc
+++ b/doc/src/demos/spectrum.qdoc
@@ -28,8 +28,34 @@
/*!
\example demos/spectrum
\title Spectrum Analyzer
-This application is a demo which uses the QtMultimedia APIs to capture and
-play back PCM audio. While either recording or playback is ongoing, the
-application performs real-time level and frequency spectrum analysis,
-displaying the results in its main window.
+
+ The Spectrum Analyzer demo shows how the \l{QtMultimedia Module} can be
+ used in Qt applications to capture and then play back an audio stream.
+
+ \image spectrum-demo.png
+
+ Because QtMultimedia allows the application to access the raw audio
+ stream, the data can either be inspected or modified by the application.
+ The Spectrum Analyzer demo displays three pieces of information while
+ audio is being either captured or played back:
+
+ \list
+ \o Information about the raw audio stream, shown in the uppermost widget:
+ \list
+ \o The amount of data currently in the buffer, shown in blue
+ \o The segment of data which was most recently analysed to compute
+ the frequency spectrum, shown in green
+ \o The raw audio waveform, shown in white and scrolling from right to
+ left
+ \endlist
+ \o A representation of the frequency spectrum, shown at the lower left
+ \o The current RMS level of the audio stream, and the recent 'high
+ watermark' level, shown at the lower right
+ \endlist
+
+ Spectrum analysis is performed by calculating the Fast Fourier Transform
+ (FFT) of a segment of audio data. An open-source library,
+ \l{http://ldesoras.free.fr/prod.html}{FFTReal}, against which the
+ application is dynamically linked, is used to compute the transform.
*/
+
diff --git a/doc/src/getting-started/demos.qdoc b/doc/src/getting-started/demos.qdoc
index 94b19c3..4003988 100644
--- a/doc/src/getting-started/demos.qdoc
+++ b/doc/src/getting-started/demos.qdoc
@@ -147,6 +147,15 @@
\note The Phonon demos are currently not available for the MinGW platform.
+ \section1 Multimedia
+
+ \list
+ \o \l{demos/spectrum}{Spectrum Analyzer} demonstrates how the \l{QtMultimedia Module}
+ can be used to capture and play back an audio stream, at the same time allowing the
+ application to access the raw audio data. This application analyzes the audio stream
+ in order to display a frequency spectrum.
+ \endlist
+
\section1 Animation
\list
diff --git a/doc/src/images/spectrum-demo.png b/doc/src/images/spectrum-demo.png
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