<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Hi,<div class=""><br class=""></div><div class="">I'm running a GST 18.4 python app. This app communicates with a Chrome JS app on the same network.</div><div class=""><br class=""></div><div class="">The app is able to send and receive VP8, but I'm having a problem with H.264, in case the Python app (webrtcbin based) is the ANSWERER. The problem is not there if the Python app is the OFFERER.</div><div class=""><br class=""></div><div class="">First the positive case: This is my H.264 pipeline in the Python app. If the Python app OFFERS, the video appears in Chrome.</div><div class=""><br class=""></div><div class=""><div style="background-color: rgb(255, 255, 255); font-family: "Fira Code", Menlo, Monaco, "Courier New", monospace, Menlo, Monaco, "Courier New", monospace; line-height: 21px; white-space: pre;" class=""><div class=""><span style="color: #00950e;font-style: italic;" class=""># H.264 TEST VIDEO</span></div><div class="">PIPELINE_TEST_H264 <span style="color: #7f0055;" class="">=</span> <span style="color: #d126d1;" class="">'''</span></div><div class=""><span style="color: #d126d1;" class="">webrtcbin name=webrtcbin bundle-policy=max-bundle stun-server=<a href="stun://stun.l.google.com:19302" class="">stun://stun.l.google.com:19302</a></span></div><div class=""><span style="color: #d126d1;" class="">videotestsrc is-live=true pattern=smpte ! video/x-raw,width=1280,height=720 ! videoconvert ! x264enc ! rtph264pay ! </span></div><div class=""><span style="color: #d126d1;" class="">queue ! application/x-rtp,media=video,encoding-name=H264 ! webrtcbin.</span></div><div class=""><span style="color: #d126d1;" class="">'''</span></div><br class=""></div></div><div class=""><br class=""></div><div class="">The SDP handshake is like so:</div><div class=""><br class=""></div><div class="">The OFFER sent:</div><div class=""><br class=""></div><div class=""><div class="">2021-08-14 16:44:48,800 webrtc_client.py-INFO : having sdp offer:</div><div class="">v=0</div><div class="">o=- 143230668495837560 0 IN IP4 0.0.0.0</div><div class="">s=-</div><div class="">t=0 0</div><div class="">a=ice-options:trickle</div><div class="">a=group:BUNDLE video0</div><div class="">m=video 9 UDP/TLS/RTP/SAVPF 96</div><div class="">c=IN IP4 0.0.0.0</div><div class="">a=setup:actpass</div><div class="">a=ice-ufrag:8OgtMvs3Zdn04lGPl61MEeQGtuq2XNS+</div><div class="">a=ice-pwd:GbtIZHC7CWPkgzNrnH7mWEtWNpaeWL5n</div><div class="">a=rtcp-mux</div><div class="">a=rtcp-rsize</div><div class="">a=sendonly</div><div class="">a=rtpmap:96 H264/90000</div><div class="">a=rtcp-fb:96 nack pli</div><div class="">a=framerate:30</div><div class="">a=fmtp:96 packetization-mode=1;profile-level-id=42c01f;sprop-parameter-sets=Z0LAH9kAUAW7AWoCAgKAAAADAIAAAB5HjBkk,aMuMsg==</div><div class="">a=ssrc:2817782937 msid:user2521903457@host-548ae76e webrtctransceiver0</div><div class="">a=ssrc:2817782937 cname:user2521903457@host-548ae76e</div><div class="">a=mid:video0</div><div class="">a=fingerprint:sha-256 1B:99:58:8C:F3:33:28:60:02:E6:11:66:74:B7:84:B4:D9:06:32:12:13:23:F0:E9:23:68:9D:C3:CC:79:85:C5</div></div><div class=""><br class=""></div><div class="">The ANSWER received (video flows):</div><div class=""><br class=""></div><div class=""><div class=""><br class=""></div><div class="">2021-08-14 16:44:48,940 webrtc_client.py-INFO : received sdp answer:</div><div class="">v=0</div><div class="">o=- 6562431427409268738 2 IN IP4 127.0.0.1</div><div class="">s=-</div><div class="">t=0 0</div><div class="">a=group:BUNDLE video0</div><div class="">a=msid-semantic: WMS</div><div class="">m=video 9 UDP/TLS/RTP/SAVPF 96</div><div class="">c=IN IP4 0.0.0.0</div><div class="">a=rtcp:9 IN IP4 0.0.0.0</div><div class="">a=ice-ufrag:OoGw</div><div class="">a=ice-pwd:egHkzRQOlN6ADWLnaltQ6AkA</div><div class="">a=ice-options:trickle</div><div class="">a=fingerprint:sha-256 20:C2:D3:AA:37:07:31:87:FA:71:D4:20:CF:50:ED:07:EA:C8:B8:1D:EA:02:73:9C:7C:AC:24:5C:F3:C9:DA:60</div><div class="">a=setup:active</div><div class="">a=mid:video0</div><div class="">a=recvonly</div><div class="">a=rtcp-mux</div><div class="">a=rtcp-rsize</div><div class="">a=rtpmap:96 H264/90000</div><div class="">a=rtcp-fb:96 nack pli</div><div class="">a=fmtp:96 level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42e01f</div></div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">The video does not appear in Chrome, if Chrome is the OFFERER. The ANSWER confirms that with "a=inactive".</div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">The OFFER generated by Chrome:</div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><div class="">2021-08-14 16:47:03,340 webrtc_client.py-INFO : received sdp offer:</div><div class="">v=0</div><div class="">o=- 6799643414674800834 2 IN IP4 127.0.0.1</div><div class="">s=-</div><div class="">t=0 0</div><div class="">a=group:BUNDLE 0</div><div class="">a=extmap-allow-mixed</div><div class="">a=msid-semantic: WMS</div><div class="">m=video 9 UDP/TLS/RTP/SAVPF 96 97 98 99 100 101 122 102 121 127 120 125 107 108 109 35 36 124 119 123 118 114 115 116 37</div><div class="">c=IN IP4 0.0.0.0</div><div class="">a=rtcp:9 IN IP4 0.0.0.0</div><div class="">a=ice-ufrag:Tyef</div><div class="">a=ice-pwd:tct8Z2AfUb1yNAT/aWDfj2OI</div><div class="">a=ice-options:trickle</div><div class="">a=fingerprint:sha-256 F6:01:90:DF:E5:67:4E:B0:9F:DF:14:1A:3B:08:2F:E8:12:ED:CC:35:EB:4D:E2:22:AF:1F:18:7C:EB:37:D7:41</div><div class="">a=setup:actpass</div><div class="">a=mid:0</div><div class="">a=extmap:1 urn:ietf:params:rtp-hdrext:toffset</div><div class="">a=extmap:2 <a href="http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time" class="">http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time</a></div><div class="">a=extmap:3 urn:3gpp:video-orientation</div><div class="">a=extmap:4 <a href="http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01" class="">http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01</a></div><div class="">a=extmap:5 <a href="http://www.webrtc.org/experiments/rtp-hdrext/playout-delay" class="">http://www.webrtc.org/experiments/rtp-hdrext/playout-delay</a></div><div class="">a=extmap:6 <a href="http://www.webrtc.org/experiments/rtp-hdrext/video-content-type" class="">http://www.webrtc.org/experiments/rtp-hdrext/video-content-type</a></div><div class="">a=extmap:7 <a href="http://www.webrtc.org/experiments/rtp-hdrext/video-timing" class="">http://www.webrtc.org/experiments/rtp-hdrext/video-timing</a></div><div class="">a=extmap:8 <a href="http://www.webrtc.org/experiments/rtp-hdrext/color-space" class="">http://www.webrtc.org/experiments/rtp-hdrext/color-space</a></div><div class="">a=extmap:9 urn:ietf:params:rtp-hdrext:sdes:mid</div><div class="">a=extmap:10 urn:ietf:params:rtp-hdrext:sdes:rtp-stream-id</div><div class="">a=extmap:11 urn:ietf:params:rtp-hdrext:sdes:repaired-rtp-stream-id</div><div class="">a=recvonly</div><div class="">a=rtcp-mux</div><div class="">a=rtcp-rsize</div><div class="">a=rtpmap:96 VP8/90000</div><div class="">a=rtcp-fb:96 goog-remb</div><div class="">a=rtcp-fb:96 transport-cc</div><div class="">a=rtcp-fb:96 ccm fir</div><div class="">a=rtcp-fb:96 nack</div><div class="">a=rtcp-fb:96 nack pli</div><div class="">a=rtpmap:97 rtx/90000</div><div class="">a=fmtp:97 apt=96</div><div class="">a=rtpmap:98 VP9/90000</div><div class="">a=rtcp-fb:98 goog-remb</div><div class="">a=rtcp-fb:98 transport-cc</div><div class="">a=rtcp-fb:98 ccm fir</div><div class="">a=rtcp-fb:98 nack</div><div class="">a=rtcp-fb:98 nack pli</div><div class="">a=fmtp:98 profile-id=0</div><div class="">a=rtpmap:99 rtx/90000</div><div class="">a=fmtp:99 apt=98</div><div class="">a=rtpmap:100 VP9/90000</div><div class="">a=rtcp-fb:100 goog-remb</div><div class="">a=rtcp-fb:100 transport-cc</div><div class="">a=rtcp-fb:100 ccm fir</div><div class="">a=rtcp-fb:100 nack</div><div class="">a=rtcp-fb:100 nack pli</div><div class="">a=fmtp:100 profile-id=2</div><div class="">a=rtpmap:101 rtx/90000</div><div class="">a=fmtp:101 apt=100</div><div class="">a=rtpmap:122 VP9/90000</div><div class="">a=rtcp-fb:122 goog-remb</div><div class="">a=rtcp-fb:122 transport-cc</div><div class="">a=rtcp-fb:122 ccm fir</div><div class="">a=rtcp-fb:122 nack</div><div class="">a=rtcp-fb:122 nack pli</div><div class="">a=fmtp:122 profile-id=1</div><div class="">a=rtpmap:102 H264/90000</div><div class="">a=rtcp-fb:102 goog-remb</div><div class="">a=rtcp-fb:102 transport-cc</div><div class="">a=rtcp-fb:102 ccm fir</div><div class="">a=rtcp-fb:102 nack</div><div class="">a=rtcp-fb:102 nack pli</div><div class="">a=fmtp:102 level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42001f</div><div class="">a=rtpmap:121 rtx/90000</div><div class="">a=fmtp:121 apt=102</div><div class="">a=rtpmap:127 H264/90000</div><div class="">a=rtcp-fb:127 goog-remb</div><div class="">a=rtcp-fb:127 transport-cc</div><div class="">a=rtcp-fb:127 ccm fir</div><div class="">a=rtcp-fb:127 nack</div><div class="">a=rtcp-fb:127 nack pli</div><div class="">a=fmtp:127 level-asymmetry-allowed=1;packetization-mode=0;profile-level-id=42001f</div><div class="">a=rtpmap:120 rtx/90000</div><div class="">a=fmtp:120 apt=127</div><div class="">a=rtpmap:125 H264/90000</div><div class="">a=rtcp-fb:125 goog-remb</div><div class="">a=rtcp-fb:125 transport-cc</div><div class="">a=rtcp-fb:125 ccm fir</div><div class="">a=rtcp-fb:125 nack</div><div class="">a=rtcp-fb:125 nack pli</div><div class="">a=fmtp:125 level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42e01f</div><div class="">a=rtpmap:107 rtx/90000</div><div class="">a=fmtp:107 apt=125</div><div class="">a=rtpmap:108 H264/90000</div><div class="">a=rtcp-fb:108 goog-remb</div><div class="">a=rtcp-fb:108 transport-cc</div><div class="">a=rtcp-fb:108 ccm fir</div><div class="">a=rtcp-fb:108 nack</div><div class="">a=rtcp-fb:108 nack pli</div><div class="">a=fmtp:108 level-asymmetry-allowed=1;packetization-mode=0;profile-level-id=42e01f</div><div class="">a=rtpmap:109 rtx/90000</div><div class="">a=fmtp:109 apt=108</div><div class="">a=rtpmap:35 AV1X/90000</div><div class="">a=rtcp-fb:35 goog-remb</div><div class="">a=rtcp-fb:35 transport-cc</div><div class="">a=rtcp-fb:35 ccm fir</div><div class="">a=rtcp-fb:35 nack</div><div class="">a=rtcp-fb:35 nack pli</div><div class="">a=rtpmap:36 rtx/90000</div><div class="">a=fmtp:36 apt=35</div><div class="">a=rtpmap:124 H264/90000</div><div class="">a=rtcp-fb:124 goog-remb</div><div class="">a=rtcp-fb:124 transport-cc</div><div class="">a=rtcp-fb:124 ccm fir</div><div class="">a=rtcp-fb:124 nack</div><div class="">a=rtcp-fb:124 nack pli</div><div class="">a=fmtp:124 level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=4d0032</div><div class="">a=rtpmap:119 rtx/90000</div><div class="">a=fmtp:119 apt=124</div><div class="">a=rtpmap:123 H264/90000</div><div class="">a=rtcp-fb:123 goog-remb</div><div class="">a=rtcp-fb:123 transport-cc</div><div class="">a=rtcp-fb:123 ccm fir</div><div class="">a=rtcp-fb:123 nack</div><div class="">a=rtcp-fb:123 nack pli</div><div class="">a=fmtp:123 level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=640032</div><div class="">a=rtpmap:118 rtx/90000</div><div class="">a=fmtp:118 apt=123</div><div class="">a=rtpmap:114 red/90000</div><div class="">a=rtpmap:115 rtx/90000</div><div class="">a=fmtp:115 apt=114</div><div class="">a=rtpmap:116 ulpfec/90000</div><div class="">a=rtpmap:37 flexfec-03/90000</div><div class="">a=rtcp-fb:37 goog-remb</div><div class="">a=rtcp-fb:37 transport-cc</div><div class="">a=fmtp:37 repair-window=10000000</div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">The ANSWER generated by webrtcbin:</div><div class=""><br class=""></div><div class="">2021-08-14 16:47:07,336 webrtc_client.py-INFO : having sdp answer:</div><div class="">v=0</div><div class="">o=- 6799643414674800834 2 IN IP4 0.0.0.0</div><div class="">s=-</div><div class="">t=0 0</div><div class="">a=group:BUNDLE 0</div><div class="">m=video 9 UDP/TLS/RTP/SAVPF 96</div><div class="">c=IN IP4 0.0.0.0</div><div class="">a=ice-ufrag:ej11/cl3FCkkhNmNliiql1R5MX5MFn/g</div><div class="">a=ice-pwd:SgutRYS/iWj9l8WvWvXGzrohbIiTLK+f</div><div class="">a=mid:0</div><div class="">a=rtcp-mux</div><div class="">a=setup:active</div><div class="">a=rtpmap:96 VP8/90000</div><div class="">a=rtcp-fb:96 nack pli</div><div class="">a=rtcp-fb:96 ccm fir</div><div class="">a=inactive</div><div class="">a=fingerprint:sha-256 BD:5C:65:0E:D3:75:67:8B:80:71:57:D5:08:14:70:1A:BB:4F:51:F8:54:53:80:17:8C:3E:44:DB:EA:E5:04:06</div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">What could be the problem or what to do to narrow it down?</div></div><div class=""><br class=""></div><div class="">TIA</div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div></body></html>