title: How to connect filter src to nvstreammux sink
body: <p>I have a pipeline like this, </p>
  
  <pre><code>gst-launch-1.0 v4l2src ! 'video/x-raw,format=(string)YUY2' ! nvvidconv ! 'video/x-raw(memory:NVMM),format=(string)NV12' ! nvvidconv ! 'video/x-raw,format=(string)NV12' ! nvvideoconvert ! 'video/x-raw(memory:NVMM),format=(string)NV12' ! mux.sink_0 nvstreammux live-source=1 name=mux batch-size=1 width=640 height=480 ! nvinfer config-file-path=/opt/nvidia/deepstream/deepstream-4.0/sources/apps/sample_apps/deepstream-test1/dstest1_pgie_config.txt batch-size=1 ! nvmultistreamtiler rows=1 columns=1 width=640 height=480 ! nvvideoconvert ! nvdsosd ! nvegltransform ! nveglglessink
  </code></pre>
  
  <p>and I am trying to connect the capsfilter 'video/x-raw(memory:NVMM),format=(string)NV12' to nvstreammux. Should I create pads or bins between those two? and how? </p>