Multitrack publish and play with AMS

Webrtc multitrack lets us stream multiple video/audio tracks through a single WebRTC connection. In order to use Multitrack feature, the SDP semantic should be set as Unified Plan which is also set by defalut in AMS v2.4.3 and above.

With multitrack streams, you can play different groups of streams with a single broadcast ID. Then, you can start playing those groups of streams with one play request and most importantly through a single WebRTC connection and this decreases resource usage as well.

Terminologies related to multitrack

Main track: StreamId of a group is referred as main track.
Sub track: The streams in a group with different streamIds are referred as sub tracks.

In order to group the broadcasts into a single broadcast (main track), you need to do one of the items below.

• For WebRTC streams, you need to pass group ID as main track while calling publish method of webrtcAdaptor in the SDK.

https://{AMS_URL}:5443/AppName/?mainTrack={GROUP_ID}

• For RTMP streams, you need to add multiTrack parameter to the stream ID as:

rtmp://{AMS_URL}:1935/WebRTCAppEE/{STREAM_ID}?mainTrack={GROUP_ID}

Publishing multitrack streams

Let's publish a stream with streamid=video to the sample WebRTCAppEE application with group streamId (main track) as main.

rtmp://{AMS_URL}:1935/WebRTCAppEE/video?mainTrack=main

Now publish streams with different audio subtracks as required.

Let's say there are two addio tracks with streamId as audio1 and audio2.

Playing multitrack streams

Multitrack streams can be played with the sample page, multitrackplayer.html

https://{AMS_URL}:5443/WebRTCAppEE/multitrackplayer.html

1. Write the group id in the text box
2. Request the sub-tracks by clicking the Tracks button
3. Select the tracks you want to play and click the Play button
4. If a new subtrack is added to the group, it will be played automatically

You can enable or disable video/audio feed for a sub-track with enableTrack(mainTrackId, trackId, enabled) methods in the webrtc-adaptor SDK.

Multitrack conference

We have implemented a new sample conference page, conference-room.html and this page is compatible with multitrack playback.

The main-track (group) id will be the same as the room id.

https://{AMS_URL}:5443/WebRTCAppEE/conference-room.html?roomName=main

In Multitrack conference the play request is called once for the roomId.