Can we add multiple video track in same peer connection in case of streamer / media sender ? Tried but its only accept the lastly added video track

[Nikhil2206]

@paullouisageneau
I tried adding 2 video track like this

`
const rtc::SSRC ssrc1 = 42;
rtc::Description::Video media1("video1", rtc::Description::Direction::SendOnly);
media1.addH264Codec(96); // Must match the payload type of the external h264 RTP stream
media1.addSSRC(ssrc1, "video-send");
auto track1 = pc->addTrack(media1);

const rtc::SSRC ssrc2 = 43;
rtc::Description::Video media2("video2", rtc::Description::Direction::SendOnly);
media2.addH264Codec(97); // Must match the payload type of the external h264 RTP stream
media2.addSSRC(ssrc2, "video-send");
auto track2 = pc->addTrack(media2);
`
and trying to send frames over both stream
I see only one track is received in the browser and playing successfully

I checked the SPD for offer, it show only lastly added video track and does not show first one

Does libdatachannel support multiple video tracks ? if yes what could be wrong in my code ?

[paullouisageneau]

libdatachannel supports multiple video tracks. If only the second one appears in the offer, it would mean the first one is either destroyed before setLocalDescription() is called (because the shared_ptr is destroyed, for instance), or replaced by the second one (because it has the same mid, for instance).

For the browser to play both videos, you must ensure a few things: payload types for the exact same codec must be the same across the entire description (so you have to use 96 for both tracks), and each independent streams must have a different cname and msid (set in addSSRC()).

[Nikhil2206]

thank you ! for answering, I had realised that, this was happening because of same mid used. I corrected and now I can see both videos on browser as well.