Forum Discussion

dglar's avatar
dglar
Reel Rookie
2 years ago

Determining if hls/dash stream is live

I need to be able to play streams (hls and dash) without knowing if they are live or vod, and set the start time accordingly. So far, I've tried just setting `playStart=-1` but the results are all over the place. Most live streams do start at the edge, but some fail with `buffer:search:demux.dash:Cannot seek to video at <timestamp>/<framerate>: error -36`. For vod, most play the last segment and stop as expected, although some do actually still start from the beginning despite the -1.

I see from the query/media-player ECP endpoint that there is indeed an `is_live` attribute that's exactly what I need, but I can't find this in any of the Video node fields. Loopback ECP access is not allowed so I can't simply use this.

Or a way to peek at the hls variant manifest to check for `#EXT-X-ENDLIST`. I do see that `manifestData` is available for dash, but of course manual parsing seems heavy handed.

The current goal is to load the video in a prebuffered state to be able to determine liveness, and then seek accordingly and start playback, similar to the solution discussed here: https://community.roku.com/t5/Roku-Developer-Program/Start-live-channel-with-timeshift-at-live-position/m-p/667925

I am hoping that seeking to `duration` will resolve issues with that particular live dash stream and perhaps others.

 

Thanks

 

ETA: I did see in the documentation that the `pauseBuffer*` fields are only valid for live video, but it looks like they're set for vods as well.

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6 Replies

  • renojim's avatar
    renojim
    Community Streaming Expert
    2 years ago

    I'd have to test it to be sure, but I'd be willing to be ECP just returns whether the Live attribute of the Content metadata has been set to true, which is something you'd have to do yourself.  I don't think the device has any way to determine whether a stream is live, but maybe someone has some ideas.

    • dglar's avatar
      dglar
      Reel Rookie
      2 years ago

      Thanks but content metadata `Live` is only responsible for displaying "Live" in the progress bar. Meanwhile, ECP's `is_live` is indeed whether the stream is live or vod.

      • renojim's avatar
        renojim
        Community Streaming Expert
        2 years ago

        Interesting.  Well I did say I'd have to test, and now that I have, it does look like you can get it from ECP.  As you noted for HLS, it's probably simply that live streams don't have an ending #EXT-X-ENDLIST, but if is_live is exposed through through the Video Node, I don't see it in the documentation.  Removing #EXT-X-ENDLIST from an m3u8 file sure enough gets ECP to return true for is_live.  Personally (after years of trying to fight Roku limitations and oddities), I'd take the "heavy handed" approach, but perhaps someone like RokuBen might know something.