How to create equalizer for HLS along with AVPlayer?

I saw equalizer in apps like Musi and Spotify. I think (but not sure) they use HLS streaming. If so, how to implement such an equalizer for HLS?

I searched and tried several approaches but so far none works, like:

  1. AVAudioEngine seems only support local file;
  2. Download .ts and merge into .mp3 to make it local can not guarantee real time effect;
  3. MTAudioProcessingTap needs the audio track. For remote .mp3 I can extract the audio track but not for HLS.

Any suggestion?

How to create equalizer for HLS along with AVPlayer?
 
 
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