Invalid Track Composite archive when the participant publishes new tracks

[clemos]

Hi !

The blog post about Egress launch reads the following:
https://blog.livekit.io/livekit-universal-egress-launch/

Track Composite automatically synchronizes and combines a single participant's audio and video tracks, and exports them to a standalone file or RTMP stream. This option is handy for recording each participant individually, such as during a live performance.

However, we made some tests, and it seems that in track composite mode, if the participant publishes a new track, the track is not added to the output video archive. For instance, if a participant has an audio track published, starts egress track composite, and then publishes a video track, the resulting archive will only contain the audio stream.

Is it the expected behavior ? In this case, should I start a new track composite egress whenever a new track is published within the participant's stream ? More generally, how to deal with change of camera or microphone ?

Thanks a lot 🙏

[davidzhao]

Yes, this is expected with the current APIs. You need both audio & video IDs before starting the egress.

We are evaluating a simpler option where you can pass in only the participant's identity.

Currently we would recommend starting the composite only after both microphone and camera are published.

When camera and microphone are changed, you can use the replaceTrack API to swap the input devices without unpublishing the track first.

[jibon57]

@davidzhao having option to automatically start capturing media will be helpful instated of passing media id every time. Will be waiting for this feature 🙏