title: gstreamer-1.0 get data from GstSample in GstAppSink
body: <p>I am trying to get data from a GstSample to process it in my app sink.
  But I cannot find a way to extract the data from a sample.
  I have set the callball function "new-sample":</p>
  
  <pre><code>static void GStPipeline::new_sample (GstAppSink *sink, CustomData *data) {
      GstSample* sample;
  
      sample = gst_app_sink_pull_sample(data-&gt;app_sink);
  
      if (sample) {
          data-&gt;sampleBuffer[data-&gt;num_samples] =  sample;
  
          data-&gt;num_samples++;
      }
  
      gst_sample_unref(sample);
  }
  </code></pre>
  
  <p>Am I missing some basic concept? Is it true, that since gstreamer-1.0 I have to provide a callback "new-sample" instead of "pull-buffer" ? For my understanding, a buffer contains the samples. </p>