API sync QoS

[amtins]

QoS

• [x] should the heartbeat be sent when the player is paused?
• [x] how often should the heartbeat be sent?
• [x] when should the end event be sent?
• [x] what value should be set for a live with a seekable window?
• [x] Which player position should be sent for live-only / DVR streams? (time vs. offset from live edge)
• [x] What startup times are we measuring? (in a QoE approach a time of 0 should be sent if a process is not visible, in a QoS approach we can send the real value)
• [x] What is the playback duration we send? Is it measured in wall-clock time or in the reference frame of the stream? Should we send both values, e.g. to be able to measure average playback speeds?
• [x] Is playback_duration exposed as a player metric?

[amtins]

should the heartbeat be sent when the player is paused?

Yes

how often should the heartbeat be sent?

Every 30 seconds no matter the playback state

when should the stop event be sent?

Aside from the usual media ended the stop event is sent when transitioning from a media to another.

what value should be set for a live with a seekable window?

The value of the live window

What is the playback duration we send? Is it measured in wall-clock time or in the reference frame of the stream? Should we send both values, e.g. to be able to measure average playback speeds?

• The playback_duration we send is the wall-clock duration, cf. documentation
• No need to send the duration in the reference frame of the stream yet. Could be used to calculate average playback speeds, but maybe having dedicated playback speed change events would be even better

Is playback_duration exposed as a player metric?

• Already available on Android. Not yet for Apple, but could be. Something that would require a discussion on video.js (vhs.stats). At the moment it's a nice to have but not mandatory.

Which player position should be sent for live-only / DVR streams? (time vs. offset from live edge)

• Offset from live edge seems to be a good option, live-only will always be 0, cf. documentation

What startup times are we measuring? (in a QoE approach a time of 0 should be sent if a process is not visible, in a QoS approach we can send the real value)

• Both metadata and asset timings represent the QoE, e.g both 0 if preload was complete and the user experience an instantaneous startup.
• On the we the loadeddata is not sent automatically when the date is loaded on a live stream.