When following the steps as laid out in the HEVC Interlaced whitepaper(included in the 2018R1 release) to use the CBR SW bit rate controller(MFX_RATECONTROL_CBR), initially everything seems to work fine.
However, after somewhere between 8-16 hours of continuous real-time encoding it seems that the bitrate controller goes crazy and the encoded video drops. In our case we started encoding a 1080i stream in about 6 Mbps but after the 8 hours it looks rather like the encoding is done at a very, very low bitrate i.e. it's completely unwatchable. The resulting elementary stream does however keep the correct overall bit rate but the encoding looks looks bad.
We have tested using the same rate controller on pure progressive material and are getting the exact same result.
Has anyone seen this behvaiour?