In Reader.Go:
in the following line:
case !state.tagIframeStreamInf && strings.HasPrefix(line, "#EXT-X-I-FRAME-STREAM-INF:"):
you use only the first iframe manifest found and not all.

also, the playlist iframe segments has no offset and linit due to lin "} else if state.tagRange { " in:

case !strings.HasPrefix(line, "#"):
if state.tagInf {
p.Append(line, state.duration, title)
state.tagInf = false
} else if state.tagRange {

because i have state.tagInf and state.tagRange so "else if " isnt good enough and should be:

if state.tagInf {
p.Append(line, state.duration, title)
state.tagInf = false
}
if state.tagRange {