Subscribed to videoTrack function called but shouldn't

[spacedema]

Description

When I join a room that already has participants with shared video track, I check it with:

func subscribed(to videoTrack: TVIRemoteVideoTrack,
                    publication: TVIRemoteVideoTrackPublication,
                    for participant: TVIRemoteParticipant) {
        log.debug("Subscribed to Participant's \(participant.identity) video track")
        if let videoTrack = publication.remoteTrack, videoTrack.isEnabled {
            ... participant is streaming video, updating UI
        }
    }

And everything works fine until 2nd call with same participants. I get event after participant did connect to room that he started video stream and after 1 sec ended video stream. My UI is not working correctly because of this.

Steps to Reproduce

0. 1st Call

1. Participant A starts call and connects to room ABC and doesn't share videoTrack

2. Participant B connects to room ABC and shares one videoTrack

3. Participant C connects to room ABC and doesn't share videoTrack

4. Call ended

5. 2nd Call

6. Participant A starts call and connects to room ABC and doesn't share videoTrack

7. Participant B connects to room ABC and doesn't share videoTrack

8. Participant C connects to room ABC and doesn't share videoTrack

Expected Behavior

func subscribed(to videoTrack: TVIRemoteVideoTrack) doesn't call for any participant in 2nd call

Actual Behavior

func subscribed(to videoTrack: TVIRemoteVideoTrack) called for participant B and after ~1 sec Unsubscribe and Unpublish functions called

🔸12:54:31:225 [DBG] (TwilioService+TVIRemoteDelegate:17) { }: Subscribed to Participant's B video track
🔸12:54:32:014 [DBG] (TwilioService+TVIRemoteDelegate:30) { }: Unsubscribed to Participant's B video track
🔸12:54:32:020 [DBG] (TwilioService+TVIRemoteDelegate:57) { }: Participant B unpublished video track

Reproduces How Often

100%

Versions

2.10.0

[ceaglest]

Hi @spacedema,

The behavior you are describing is not expected if you are using a unique Room for each call.

4. Call ended

Are you reusing the same Room without disconnecting Participants A, B, and C from the first call? If you don't disconnect the Participants (by calling Room.disconnect() and waiting for roomDidDisconnect()) then they might hang around for up to 2 minutes using the 2.x SDK.

If you can provide a Room SID I'd be happy to take a look.

Regards,
Chris

[spacedema]

Hi, Chris

I don't reuse same Room and I call Room.disconnect() at every call end.

If you can provide a Room SID I'd be happy to take a look.

Do you mean that I should reproduce issue and send you Sids from 1st and 2nd call?

Regards,
Sergey

[ceaglest]

Do you mean that I should reproduce issue and send you Sids from 1st and 2nd call?

Yes, would this be possible @spacedema? I should be able to tell from the Room SIDs more about what is going on and if there is a bug.

[spacedema]

1st call Room Sid: RM22f2049b32db4140f6112012529cb259
2nd call Room Sid: RM693e59bbee7b79b1eb4bc5f5e1c07c09

[ceaglest]

Hi @spacedema,

Sorry for the delayed response. It seems like there is a logical bug in your application code. In both of the Rooms, video was shared:

RM22f2049b32db4140f6112012529cb259

• After connecting to the Room. P2 (da6f8d75-7287-56fe-8b0f-200878d2e29c) waits ~7 seconds and publishes a VideoTrack. Was this intentional? It is not described in either of the scenarios above.

2019-06-14T08:37:19.587Z: P2 sent update with track changes: video was added revision: 3

RM693e59bbee7b79b1eb4bc5f5e1c07c09

• This corresponds to scenario 1 (?).
• P3 connects with a video Track, then P3 unpublishes the same track

2019-06-14T08:37:53.092Z: P3 sent connect with audio + data + video tracks and ICE servers acquired from ECS
2019-06-14T08:37:53.895Z: P3 sent update with track changes: video was removed revision: 2

Best,
Chris

[spacedema]

After connecting to the Room. P2 (da6f8d75-7287-56fe-8b0f-200878d2e29c) waits ~7 seconds and publishes a VideoTrack. Was this intentional? It is not described in either of the scenarios above.

Yes, it was intentional. I wrote that "Participant B connects to room ABC and shares one videoTrack"
Probably I should clarify that the user does not connect to Room with video track, but publish the video track a little later, after ~7 seconds. Apologise if I misled you.

This corresponds to scenario 1 (?).

This corresponds to second scenario (2nd call, items 5-8). Why user (who published video track in 1st call) publish and immediately unpublish video track in second call?

[ceaglest]

Hi @spacedema,

Sorry that I did not respond to your last message, but I hope you were able to solve this issue. Normally Participants are subscribed to all the Tracks in a Room. The exceptions occur in a Group Room when you:

1. Exclude tracks with the subscribe rules API.
2. Connect as a publish only Participant.
3. Don't support the publisher's codec.

I hope that helps. If you have any more questions let us know.

Thanks,
Chris