Major API change: encapsulate NALs within libx264
libx264 now returns NAL units instead of raw data. x264_nal_encode is no longer a public function. See x264.h for full documentation of changes. New parameter: b_annexb, on by default. If disabled, startcodes are replaced by sizes as in mp4. x264's VBV now works on a NAL level, taking into account escape codes. VBV will also take into account the bit cost of SPS/PPS, but only if b_repeat_headers is set. Add an overhead tracking system to VBV to better predict the constant overhead of frames (headers, NALU overhead, etc).