seekRange.start when playing Live HLS without moving window is moving.

[bwallberg]

Have you read the FAQ and checked for duplicate open issues?
Yes, however I believe they have been closed based on incorrect assumptions. ( see below )

If the problem is related to FairPlay, have you read the tutorial?
N/A

What version of Shaka Player are you using?
4.16.8

Can you reproduce the issue with our latest release version?
Yes

Can you reproduce the issue with the latest code from main?
Yes

Are you using the demo app or your own custom app?
Demo app

If custom app, can you reproduce the issue using our demo app?
N/A

What browser and OS are you using?
Chrome/Firefox - MacOS

For embedded devices (smart TVs, etc.), what model and firmware version are you using?
N/A

What are the manifest and license server URIs?
We have three manifests that play for 30 minutes each so at any point one of these three should be live.

1. https://live.streaming.a2d.tv/asset/20818712.isml/.m3u8
2. https://live.streaming.a2d.tv/asset/20818713.isml/.m3u8
3. https://live.streaming.a2d.tv/asset/20818714.isml/.m3u8

What configuration are you using? What is the output of player.getNonDefaultConfiguration()?
Same as demo app

What did you do?

1. Play one of the provided manifests ( one of them should be live at all times )
2. Run document.querySelector("video").seekable.start(0) in the console

What did you expect to happen?
The value should be 0 as the available segments are static in the manifest, new segments are simply added

What actually happened?
The value changes.

Are you planning to send a PR to fix it?
Nothing planned at the moment, but hopefully.

This has been reported before 2 or 3 times ( that I can find ) and the answer has been that we can use availabilityWindowOverride and that shaka only emulates what is done in Safari.

However while the safari video controls does not allow seeking in live streams the seek range is correct and you can actually seek in that stream ( run document.querySelector("video").seekable.start(0) )

[joeyparrish]

I think there's a mistake in your content. This type of content (expanding segment list, never removing segments from availability) should have #EXT-X-PLAYLIST-TYPE:EVENT. See also https://developer.apple.com/documentation/http-live-streaming/event-playlist-construction

[bwallberg]

I think there's a mistake in your content. This type of content (expanding segment list, never removing segments from availability) should have #EXT-X-PLAYLIST-TYPE:EVENT. See also https://developer.apple.com/documentation/http-live-streaming/event-playlist-construction

I tested adding #EXT-X-PLAYLIST-TYPE:EVENT to the manifest using a proxy and indeed that does resolve the issue in shaka, so that is good 👍 I will check if we can use that as I agree that would seem most appropriate for the type of stream we expect.

That being said the value is optional and the behavior in shaka does differ from safari. I would expect shaka to not remove segments from the seekable range unless the #EXT-X-MEDIA-SEQUENCE value is updated.

For example if I have a live event with a moving window of x minutes then the window won't start moving until the event has played for x minutes.
I think that with the current implementation if someone starts watching the stream before the stream has reached it's target window size they will essentially have the window size that they started with whereas if they reload the stream they have a bigger window.

[shaka-bot]

Closing due to inactivity. If this is still an issue for you or if you have further questions, the OP can ask shaka-bot to reopen it by including @shaka-bot reopen in a comment.

[bwallberg]

@shaka-bot reopen

Still an issue. Does the shaka team agree that it's should be fixed? Just so we know that it's worth spending time on fixing :)