I failed to use MFXVideoENCODE.reset to change the bitrate dynamically. I flushed the frames in buffer and used GetVideoParam to retrieve the parameter. After change the TargetKbps and reset, it returned code 5 with leaving bitrate unchanged. I used CBR ratecontrol. Any suggestion?
If Reset returned 5 (MFX_WRN_INCOMPATIBLE_VIDEO_PARAM), then you can call GetVideoParam after the Reset call to see what parameter had to be changed. If nothing at all changed, than the new TargetKbps is not a usable value for the other parameters set (maybe too high for the profile/level?)