I digg more into this, and I saw an option in experimental features in safari to enable WebRTC VP9 codec. I checked that, restarted safari and then video started working. Although, it is experimental feature as of now so I would give preference to h264 video codec.
Here is RTP capabilities configured on my server. -
{
"codecs": [
{
"kind": "video",
"mimeType": "video/VP9",
"clockRate": 90000,
"rtcpFeedback": [
{
"type": "nack",
"parameter": ""
},
{
"type": "nack",
"parameter": "pli"
},
{
"type": "ccm",
"parameter": "fir"
},
{
"type": "goog-remb",
"parameter": ""
},
{
"type": "transport-cc",
"parameter": ""
}
],
"parameters": {},
"preferredPayloadType": 100
},
{
"kind": "video",
"mimeType": "video/rtx",
"preferredPayloadType": 101,
"clockRate": 90000,
"parameters": {
"apt": 100
},
"rtcpFeedback": []
},
{
"kind": "audio",
"mimeType": "audio/opus",
"clockRate": 48000,
"channels": 2,
"rtcpFeedback": [
{
"type": "transport-cc",
"parameter": ""
}
],
"parameters": {},
"preferredPayloadType": 102
}
],
"headerExtensions": [
{
"kind": "audio",
"uri": "urn:ietf:params:rtp-hdrext:sdes:mid",
"preferredId": 1,
"preferredEncrypt": false,
"direction": "sendrecv"
},
{
"kind": "video",
"uri": "urn:ietf:params:rtp-hdrext:sdes:mid",
"preferredId": 1,
"preferredEncrypt": false,
"direction": "sendrecv"
},
{
"kind": "video",
"uri": "urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id",
"preferredId": 2,
"preferredEncrypt": false,
"direction": "recvonly"
},
{
"kind": "video",
"uri": "urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id",
"preferredId": 3,
"preferredEncrypt": false,
"direction": "recvonly"
},
{
"kind": "audio",
"uri": "http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time",
"preferredId": 4,
"preferredEncrypt": false,
"direction": "sendrecv"
},
{
"kind": "video",
"uri": "http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time",
"preferredId": 4,
"preferredEncrypt": false,
"direction": "sendrecv"
},
{
"kind": "audio",
"uri": "http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01",
"preferredId": 5,
"preferredEncrypt": false,
"direction": "recvonly"
},
{
"kind": "video",
"uri": "http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01",
"preferredId": 5,
"preferredEncrypt": false,
"direction": "sendrecv"
},
{
"kind": "video",
"uri": "http://tools.ietf.org/html/draft-ietf-avtext-framemarking-07",
"preferredId": 6,
"preferredEncrypt": false,
"direction": "sendrecv"
},
{
"kind": "video",
"uri": "urn:ietf:params:rtp-hdrext:framemarking",
"preferredId": 7,
"preferredEncrypt": false,
"direction": "sendrecv"
},
{
"kind": "audio",
"uri": "urn:ietf:params:rtp-hdrext:ssrc-audio-level",
"preferredId": 10,
"preferredEncrypt": false,
"direction": "sendrecv"
},
{
"kind": "video",
"uri": "urn:3gpp:video-orientation",
"preferredId": 11,
"preferredEncrypt": false,
"direction": "sendrecv"
},
{
"kind": "video",
"uri": "urn:ietf:params:rtp-hdrext:toffset",
"preferredId": 12,
"preferredEncrypt": false,
"direction": "sendrecv"
}
]
}