Hybrid only encoding partial videos

[Selur]

Did some testing:

• DGDecNV: works
  
• BestSource: cpu: stuck, opencl: stuck, cuda: works; haven't tested the rest
  
• LWLibAVSource: cpu: stops, cuda: works; haven't tested the rest
  
• FFVideoSource: works
  

Seems, that like I suspected, that something in the source causes issues with some of the source filters.
=> using another source should fix the problem on that source.
(if you have an NVIDIA card I would recommend DGDecNV, otherwise you would need to use FFMS2)

Cu Selur