How to run amcl_demo.launch and other node that read RGBd camera stream directly using the camera's API?

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Hi. I'm testing Turtlebot2 with Astra RGBd camera. When I try to run the launch file from this package, along with amcl_demo.launch, it shows the error of not able to open the device camera. And opening them in either order also show the same error. I think it's because the astra_body_tracker.cpp uses the camera's SDK and open the stream as following,

astra_streamsetconnection_t sensor;
astra_streamset_open("device/default", &sensor);

And probably amcl_demo.launch is doing the same thing. I am not sure if this astra body tracker code can be modified to read the camera topics published by the amcl_demo.launch. And modifying amcl_demo is almost an daunting task. Is there anyway to run these at the same time?