Reassemble NAL's early

I try to improve the latency and concluded the addInputData is buffering a whole frame. Which results in a extra latency of 16ms (60 fps) or 33ms (30 fps). Like the addInputDataO1 I now use the packets index to know when to reassemble NAL's. I'm not sure if this will break the other code to prevent artifects but at least on the Raspberry Pi I couldn't find any differences except for some improved latency.