I’m not having any luck getting the VP8 codec to work with WebRTC, I can replicate the problem with the Wowza WebRTC test client by simply selecting VP8 as the codec. The recording will start up without any errors (including in the browser console), but the end result is an MP4 file with just the audio and no video. I thought that VP8 needed a Webm container, not MP4, so I suspect the issue here is that the wrong container format is being used to save the incoming stream. However, I can find nothing that allows me to configure the container used for the codec, so my asusmption is that the wrong choice is being made at some point.
H264 is working with the same WebRTC set up, but I’m having issues with stream corruption in Firefox if there is a resolution change (something WebRCT seems to do every time in the first 30 seconds), so I want to see if VP8 handles this better.
I see the following in the browser console, which seems to confirm that I’m sending VP8:
v=0
o=mozilla…THIS_IS_SDPARTA-99.0 5187521585237493399 0 IN IP4 0.0.0.0
s=-
t=0 0
a=fingerprint:sha-256 A4:30:44:7F:1B:42:C9:E1:31:16:B6:CA:6B:D9:1C:49:DD:75:F5:8F:1E:1E:2A:D6:E9:39:0F:A0:5E:F1:EB:8A
a=group:BUNDLE 0 1
a=ice-options:trickle
a=msid-semantic:WMS *
m=audio 9 UDP/TLS/RTP/SAVPF 109 9 0 8 101
c=IN IP4 0.0.0.0
b=TIAS:44800
b=AS:64000
b=CT:64000
a=sendrecv
a=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level
a=extmap:2/recvonly urn:ietf:params:rtp-hdrext:csrc-audio-level
a=extmap:3 urn:ietf:params:rtp-hdrext:sdes:mid
a=ice-pwd:d3c8c3fc75524e350f772dd6a2e18720
a=ice-ufrag:094b1949
a=mid:0
a=msid:- {0d50371e-79b8-49de-91d0-71fc76ebe0b3}
a=rtcp-mux
a=fmtp:109 maxplaybackrate=48000;stereo=1;useinbandfec=1
a=rtpmap:109 opus/48000/2
a=setup:actpass
a=ssrc:3894789548 cname:{3b9cbe3c-6b73-493c-a66c-97009d305461}
m=video 9 UDP/TLS/RTP/SAVPF 120 124 121 125 126 127 97 98
c=IN IP4 0.0.0.0
b=TIAS:3309000
b=AS:3500000
b=CT:3500000
a=sendrecv
a=ice-pwd:d3c8c3fc75524e350f772dd6a2e18720
a=ice-ufrag:094b1949
a=mid:1
a=msid:- {3c7e5399-03fc-465a-ab57-83a9e52322b4}
a=rtcp-mux
a=rtcp-rsize
a=fmtp:120 max-fs=12288;max-fr=60
a=rtcp-fb:120 nack
a=rtcp-fb:120 nack pli
a=rtcp-fb:120 ccm fir
a=rtcp-fb:120 goog-remb
a=rtcp-fb:120 transport-cc
a=rtpmap:120 VP8/90000
a=setup:actpass
a=ssrc:2289918276 cname:{3b9cbe3c-6b73-493c-a66c-97009d305461}
a=ssrc:2033347002 cname:{3b9cbe3c-6b73-493c-a66c-97009d305461}
a=ssrc-group:FID 2289918276 2033347002
v=0
o=WowzaStreamingEngine-next 702090643 2 IN IP4 127.0.0.1
s=-
t=0 0
a=fingerprint:sha-256
CC:8F:F5:8C:85:C0:9F:F7:9F:66:42:8E:8B:B6:62:DA:7D:84:B0:CB:85:EC:7B:31:99:9F:2C:7B:E7:3D:16:2C
a=group:BUNDLE 0 1
a=ice-options:trickle
a=msid-semantic: WMS *
m=audio 9 UDP/TLS/RTP/SAVPF 109
c=IN IP4 0.0.0.0
b=TIAS:44800
b=AS:64000
b=CT:64000
a=recvonly
a=ice-pwd:52469d111f8b5250d257282af7d24f18
a=ice-ufrag:77dc1da4
a=mid:0
a=msid:- {0d50371e-79b8-49de-91d0-71fc76ebe0b3}
a=rtcp-mux
a=fmtp:109 maxplaybackrate=48000;stereo=1;useinbandfec=1
a=rtpmap:109 opus/48000/2
a=setup:passive
m=video 9 UDP/TLS/RTP/SAVPF 120
c=IN IP4 0.0.0.0
b=TIAS:3309000
b=AS:3500000
b=CT:3500000
a=recvonly
a=ice-pwd:52469d111f8b5250d257282af7d24f18
a=ice-ufrag:77dc1da4
a=mid:1
a=msid:- {3c7e5399-03fc-465a-ab57-83a9e52322b4}
a=rtcp-mux
a=rtcp-rsize
a=fmtp:120 max-fs=12288;max-fr=60
a=rtcp-fb:120 nack
a=rtcp-fb:120 ccm fir
a=rtpmap:120 VP8/90000
a=setup:passive
