Until now HLS implementation in nginx-rtmp made use of ffmpeg libs to create HLS fragments. That lead to such major problems as complicated compilation process, ffmpeg/avconv confusion, libavformat API limitations, uncontrollable memory allocations in ffmpeg libs etc. Besides ffmpeg may not be available on some architectures (embedded etc). That was all too serious to keep using those libs.
Today I'm introducing native HLS support. It seems to be significantly faster that before, and does not require any third-party libs. The new code in is native-hls branch. There's no separate HLS module anymore. HLS is included in main rtmp module as one of the features.
In addition to native mpeg-ts generation new HLS engine is more consistent with stream restarts.