I would like to know simple video subscription management causes some potential problems

TomohiroMaeda

Hi,

I am building a video call application where 100s of participants join the call, but each participants see other three participants video.

I am aware the best way is to manage such that each participants are subscribing video tracks of three of the other participants. Since we are currently building the MVP to release fast, we are implementing the feature by setting automatic subscription on, and playing only the first three video tracks the participant receives.

This implementation basically plays three videos but the participant subscribes all the other participants tracks. Does this cause any issue such as subscription of tracks have some workloads on the browser even though most of the tracks are not played?

Thanks,

Tomo

daily_joey

Hi @TomohiroMaeda!

It sounds like for your use case, you may benefit from disabling automatic track subscriptions by setting subscribeToTracksAutomatically to false. This means that users will only subscribe to specific participants as specified by the updateParticipants() method.

https://docs.daily.co/reference/daily-js/daily-iframe-class/properties#subscribeToTracksAutomatically

By subscribing only to the participants a user should be see, you can reduce the bandwidth usage and improve performance.

https://docs.daily.co/reference/daily-js/instance-methods/update-participant#track-subscriptions

mark_at_daily

Hi @TomohiroMaeda

Joey is right. In fact, if your application will have 100s of participants joining, you'll need to manually manage track subscriptions or else you'll exceed browser, device, and network limitations.

I understand that you want to launch fast. Fortunately, this isn't a huge lift to enable. Joey has shared links to get you going.

Another helpful tip: Not only should you subscribe to the three participants' video, but you'll also want to limit audio track subscriptions, as 100s of participants will exceed what the browser can handle in terms of concurrent audio elements. Generally, for call of greater than 50 participants, you'll want to keep this number in the range of 8-16 or lower.

Good luck and let us know if you need any additional help along the way.

TomohiroMaeda

Thank you so much for your fast and helpful response!