implemented audio decoder and some of the audio node functionality

app/node/input/media/audio/audio.cpp

@@ -2,7 +2,9 @@
 
 AudioInput::AudioInput()
 {
-
+  samples_output_ = new NodeOutput("samples_out");
+  samples_output_->set_data_type(NodeInput::kSamples);
+  AddParameter(samples_output_);
 }
 
 QString AudioInput::Name()
@@ -24,3 +26,23 @@ QString AudioInput::Description()
 {
   return tr("Import an audio footage stream.");
 }
+
+QVariant AudioInput::Value(NodeOutput *output, const rational &in, const rational &out)
+{
+  if (output == samples_output_) {
+    // Make sure decoder is set up
+    if (!SetupDecoder()) {
+      return 0;
+    }
+
+    // Retrieve audio samples from decoder
+    frame_ = decoder_->Retrieve(in, out - in);
+
+    QByteArray samples;
+    samples.resize(frame_->audio_params().samples_to_bytes(frame_->sample_count()));
+    memcpy(samples.data(), frame_->data(), static_cast<size_t>(samples.size()));
+    return samples;
+  }
+
+  return 0;
+}