Subject: [Hls-interest] CDN Tune-in with Apple Low-Latency Sample Stream

From: Rob Walch <[email-masked]>
Date: Thu, 20 Aug 2020 10:52:33 -0400

I'm having some difficulty implementing CDN Tune-in in hls.js with the
sample stream at https://ll-hls-test.apple.com/master.m3u8

My expectation is that the "age" header found in playlist responses
represents how many seconds old the playlist response is, and I can use
this to perform CDN Tune-in as described in
https://tools.ietf.org/html/draft-pantos-hls-rfc8216bis-07#appendix-C

The "age" header values I'm getting back appear more like the 2x time spent
blocking the request rather than the time the response was cached (or
simply how old this version of the playlist is). So with every attempt to
catch up using the tune-in logic, the "age" header value goes up instead of
down.

I typically see "0" for initial playlist response for a request with no
delivery directives, followed by "2" for any request with directives asking
for the next part. When requesting 2 parts in advance then age is "4", and
so on.

Is this a known issue with the php server tools?

Thank you,
Rob Walch