Egress track synchronization

Hello LiveKit Community.

We are using LiveKit Cloud for AI-powered video chats. We need to record video chat sessions but cannot afford the transcoding pricing of 2c/min. We don’t need the recordings to be instantly available. This leads me to two questions:

  • Does a participant composite egress incur transcoding charges if it only muxes together the two streams
  • Does LiveKit provide metadata for accurate synchronization of track egresses? At first sight only rough synchronization is achievable with the start timestamps.

Thank you for your help!

Please take a look at the table here, all egress types other than Track are transcoded:

That’s correct, you don’t get any cross-track offset timestamps. The recommended way to export video and audio together would be to use TrackCompositeEgress, which has transcoding charges.