Fix up documentation examples for low-level audio.

QTBUG-6548
QAudioOutput::start() crashes when the QIODevice is destructed
Made documentation clearer.

Task-number:QTBUG-6548
Reviewed-by:Justin McPherson

2 files changed, 26 insertions, 4 deletions

diff --git a/src/multimedia/audio/qaudioinput.cpp b/src/multimedia/audio/qaudioinput.cpp
index 8b368d5..d81df7a 100644
--- a/src/multimedia/audio/qaudioinput.cpp
+++ b/src/multimedia/audio/qaudioinput.cpp
@@ -77,8 +77,12 @@ QT_BEGIN_NAMESPACE
     file, you can:
 
     \code
+      QFile outputFile;   // class member.
+      QAudioInput* audio; // class member.
+    \endcode
+
+    \code
     {
-      QFile outputFile;
       outputFile.setFileName("/tmp/test.raw");
       outputFile.open( QIODevice::WriteOnly | QIODevice::Truncate );
 
@@ -91,7 +95,13 @@ QT_BEGIN_NAMESPACE
       format.setByteOrder(QAudioFormat::LittleEndian);
       format.setSampleType(QAudioFormat::UnSignedInt);
 
-      QAudioInput *audio = new QAudioInput(format, this);
+      if (QAudioDeviceInfo info(QAudioDeviceInfo::defaultInputDevice());
+      if (!info.isFormatSupported(format)) {
+          qWarning()<<"default format not supported try to use nearest";
+          format = info.nearestFormat(format);
+      }
+
+      audio = new QAudioInput(format, this);
       QTimer::singleShot(3000, this, SLOT(stopRecording()));
       audio->start(outputFile);
       // Records audio for 3000ms
@@ -109,6 +119,7 @@ QT_BEGIN_NAMESPACE
     {
       audio->stop();
       outputFile->close();
+      delete audio;
     }
     \endcode
 
diff --git a/src/multimedia/audio/qaudiooutput.cpp b/src/multimedia/audio/qaudiooutput.cpp
index f8f2fa1..1c7b617 100644
--- a/src/multimedia/audio/qaudiooutput.cpp
+++ b/src/multimedia/audio/qaudiooutput.cpp
@@ -73,7 +73,11 @@ QT_BEGIN_NAMESPACE
     simple as:
 
     \code
-      QFile inputFile;
+      QFile inputFile;     // class member.
+      QAudioOutput* audio; // class member.
+    \endcode
+
+    \code
       inputFile.setFileName("/tmp/test.raw");
       inputFile.open(QIODevice::ReadOnly);
 
@@ -86,7 +90,13 @@ QT_BEGIN_NAMESPACE
       format.setByteOrder(QAudioFormat::LittleEndian);
       format.setSampleType(QAudioFormat::UnSignedInt);
 
-      QAudioOutput *audio = new QAudioOutput(format, this);
+      QAudioDeviceInfo info(QAudioDeviceInfo::defaultOutputDevice());
+      if (!info.isFormatSupported(format)) {
+          qWarning()<<"raw audio format not supported by backend, cannot play audio.";
+          return;
+      }
+
+      audio = new QAudioOutput(format, this);
       connect(audio,SIGNAL(stateChanged(QAudio::State)),SLOT(finishedPlaying(QAudio::State)));
       audio->start(inputFile);
 
@@ -104,6 +114,7 @@ QT_BEGIN_NAMESPACE
         if(state == QAudio::IdleState) {
           audio->stop();
           inputFile.close();
+          delete audio;
         }
       }
     \endcode