Adaptive bitrate

[blodbold]

Hi,
I have a strange situation that if resource stream isn't stable(ex. internet cause lag), the result stream will be played about 2 seconds then starts to freeze.
Then I find out hls protocol has a attribute called "adaptive bitrate" which can be set to control the minimum of a input that the service can process, is there any thing like this in project's environment variables I can use?
Thank you.