hls.rb

require "open-uri"
require "uri"

playlist_uri = "http://127.0.0.1:9001/broadcasts/1/hls/index.m3u8"

Segment = Struct.new :uri, :duration

Playlist = Struct.new :seq_no, :segments

def parse_m3u8(src, uri = "")
  seq_no = src.lines.grep(/^#EXT-X-MEDIA-SEQUENCE:(\d+)/) { $1 }[0].to_i
  Playlist.new(seq_no, 
    src.lines.each_cons(2).flat_map { |tag, seg|
      tag !~/^#EXTINF:(\d+),/ ? []: Segment.new(URI.join(uri, seg.chomp), $1.to_f)
    }
  )
end

def load_playlist(uri)
  seq_no = 0
  loop {
    playlist = open(uri) {|io| parse_m3u8(io.read, uri) }

    skip_num = [0, seq_no - playlist.seq_no].max

    segments = playlist.segments[skip_num..-1]
    segments.each_with_index {|e, i| yield [e, playlist.seq_no + skip_num + i] }

    seq_no = playlist.seq_no + playlist.segments.size

    sleep [0.1, segments.reduce(0) { |acc, e| acc + e.duration }].max
  }
end

load_playlist(playlist_uri) { |seg, seq_no|
  hash = `curl -s '#{seg.uri}' | openssl dgst -sha256`.chomp
  p [seq_no, hash]
}