AudioDecoder example: Don't start event loop in case of error

If an error is set on the decoder  before starting the application's
event loop, this will cause the application to hang. Check for errors
and return if there are any.

Change-Id: Ib2d96559f8712db43973612f0e428f6d71438f02
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

3 files changed, 9 insertions, 0 deletions

diff --git a/examples/multimedia/audiodecoder/audiodecoder.cpp b/examples/multimedia/audiodecoder/audiodecoder.cpp
index 401b41bfd..891499ea2 100644
--- a/examples/multimedia/audiodecoder/audiodecoder.cpp
+++ b/examples/multimedia/audiodecoder/audiodecoder.cpp
@@ -112,6 +112,11 @@ void AudioDecoder::stop()
     m_decoder.stop();
 }
 
+QAudioDecoder::Error AudioDecoder::getError()
+{
+    return m_decoder.error();
+}
+
 void AudioDecoder::setTargetFilename(const QString &fileName)
 {
     m_targetFilename = fileName;
diff --git a/examples/multimedia/audiodecoder/audiodecoder.h b/examples/multimedia/audiodecoder/audiodecoder.h
index b6c8dc36f..cd27a9bf3 100644
--- a/examples/multimedia/audiodecoder/audiodecoder.h
+++ b/examples/multimedia/audiodecoder/audiodecoder.h
@@ -68,6 +68,7 @@ public:
     void setSource(const QString &fileName);
     void start();
     void stop();
+    QAudioDecoder::Error getError();
 
     void setTargetFilename(const QString &fileName);
 
diff --git a/examples/multimedia/audiodecoder/main.cpp b/examples/multimedia/audiodecoder/main.cpp
index 5bb240b94..a219fffe3 100644
--- a/examples/multimedia/audiodecoder/main.cpp
+++ b/examples/multimedia/audiodecoder/main.cpp
@@ -88,6 +88,7 @@ int main(int argc, char *argv[])
         cout << "Error: source filename is not specified.\n";
         return 0;
     }
+
     sourceFile.setFile(app.arguments().at(sourceFileIndex));
     if (app.arguments().size() > sourceFileIndex + 1)
         targetFile.setFile(app.arguments().at(sourceFileIndex + 1));
@@ -99,6 +100,8 @@ int main(int argc, char *argv[])
                      &app, &QCoreApplication::quit);
     decoder.setSource(sourceFile.absoluteFilePath());
     decoder.start();
+    if (decoder.getError() != QAudioDecoder::NoError)
+        return 0;
 
     return app.exec();
 }