Seeing excessive re-buffering and generally odd behaviors with HLS streams playing on Roku 11.
Since our test roku was updated to OS 11 we are seeing off behaviors with HLS streams. We are still investigating but wanted to post our current observations.
Context:
• Testing with 4400X - Roku 4, Software 11.0.0 build 4157-17
• Our channel is using SceneGraph to play videos
Behavior
• The video player will sometimes download the same .ts segment files many times over (according to our server logs). On the roku screen buffering progress is stalled at e.g. 33%, and not progressing.
• The video player sometimes will fail to initiate downloading the next segment in a timely manner (again, monitoring our server logs to infer what the video player is doing). E.g. Video player will only initiate download of segment002.ts until ~30s after having played segment001.ts in its entirety, resulting in substantial re-buffering for every hls segment
Investigation status
• We are dealing with a variety of streaming servers, some of them seem to never experience issues while others are heavily affected
• Repeat downloads of the same segment seem to be happening in particular with servers that stream with transfer-encoding: chunked
• We did not observe any of these issues with Roku 10.5. It does seems like the Roku 11 httpAgent is not behaving the same way that the Roku 10.5 was (Roku 11 httpAgent is likely being handling chunked http responses differently, and is being affected by other server-driven factors...it's difficult to isolate these factors given that the Roku platform doesn't provide much in terms of networking insight).
We investigated further, and so far we have determined that, in the context of an HLS stream delivered by an HTTP 1.1 server,
• Repeat requests to download the same .ts segment (buffering stalled) is correlated with servers using "transfer-encoding: chunked"
• Long delay before downloading the next .ts segment is correlated with servers using "connection: keep-alive"
Both issues persist as of the last update received (Roku OS 11 - build 4161-17)...I am hoping Roku staff will pick this up, because it is common to config streaming servers for chunked encoding and/or keep-alive connections.
Same here. Every other streaming device plays my HLS smoothly, except Roku.