<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div dir="auto" class="">> In general, specially at this time of the year, a lot of folks are on vacation, leaving other really busy. Expecting someone to look into your issues for free in such a short timeframe is not realistic.</div><div class=""><br class=""></div><div class="">I hear that from everybody. I don't expect anybody to do that for free. I would pay for it. But if I ask "how much" everybody is just like "omg, I have such a bunch of work"...</div><div class=""><br class=""></div><div><br class=""><blockquote type="cite" class=""><div class="">Am 22.08.2021 um 15:15 schrieb Neil Young <<a href="mailto:foreverneilyoung@googlemail.com" class="">foreverneilyoung@googlemail.com</a>>:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html; charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Could you show me an offer which is successfully handled by this app?<div class=""><br class=""></div><div class=""><br class=""><div class=""><br class=""><blockquote type="cite" class=""><div class="">Am 22.08.2021 um 14:59 schrieb Neil Young <<a href="mailto:foreverneilyoung@googlemail.com" class="">foreverneilyoung@googlemail.com</a>>:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html; charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Thanks for sharing. Will check it out. I'm aware of the MDNS candidates thing, but <div class=""><br class=""></div><div class="">a) I'm caring about those</div><div class="">b) My Chrome is disabled to send them</div><div class=""><br class=""></div><div class="">It is definitely not an ICE issue, I have<br class=""><div class=""><br class=""><blockquote type="cite" class=""><div class="">Am 22.08.2021 um 14:57 schrieb Nicolas Dufresne <<a href="mailto:nicolas@ndufresne.ca" class="">nicolas@ndufresne.ca</a>>:</div><br class="Apple-interchange-newline"><div class=""><div dir="auto" class=""><div class=""><br class=""><br class=""><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Le dim. 22 août 2021 08 h 48, Neil Young <<a href="mailto:foreverneilyoung@googlemail.com" class="">foreverneilyoung@googlemail.com</a>> a écrit :<br class=""></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word;line-break:after-white-space" class="">BTW: I will also be happy to hand out a POC app to everybody willing to help. You would only need to have a webrtcbin capable installation of GST and Python3. Works out of the box, no strings attached.<br class=""></div></blockquote></div></div><div dir="auto" class=""><br class=""></div><div dir="auto" class="">An answering app, I didn't link it before cause it's demoware. See the known issue about mdns candidates though, this is a missing feature that can pause problem.</div><div dir="auto" class=""><br class=""></div><div dir="auto" class=""><a href="https://gitlab.collabora.com/showcases/ibc-2019/multistream-server" class="">https://gitlab.collabora.com/showcases/ibc-2019/multistream-server</a><br class=""></div><div dir="auto" class=""><br class=""></div><div dir="auto" class="">In general, specially at this time of the year, a lot of folks are on vacation, leaving other really busy. Expecting someone to look into your issues for free in such a short timeframe is not realistic.</div><div dir="auto" class=""><br class=""></div><div dir="auto" class=""><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word;line-break:after-white-space" class=""><div class=""><br class=""><blockquote type="cite" class=""><div class="">Am 22.08.2021 um 14:46 schrieb Neil Young <<a href="mailto:foreverneilyoung@googlemail.com" target="_blank" rel="noreferrer" class="">foreverneilyoung@googlemail.com</a>>:</div><br class=""><div class=""><div style="word-wrap:break-word;line-break:after-white-space" class="">Well, I have published everything I did so far. I confirm, it works if webrtc/python is the offerer and it also works as described with an incoming offer, if the pipleline is using vp8 instead of H.264.<div class=""><br class=""></div><div class="">But it does not no work with H.264. And unless anybody points me to the obvious mistake I have made with my handling there is nothing to be taken back with my conclusion.</div><div class=""><br class=""></div><div class="">Prove me wrong, if you can. It doesn't help just to say "it works". There are very rare sample of answering apps with webrtcbin. And I'm doing nothing else then those.</div><div class=""> </div><div class=""><br class=""></div><div class=""><br class=""><div class=""><br class=""><blockquote type="cite" class=""><div class="">Am 22.08.2021 um 14:41 schrieb Nicolas Dufresne <<a href="mailto:nicolas@ndufresne.ca" target="_blank" rel="noreferrer" class="">nicolas@ndufresne.ca</a>>:</div><br class=""><div class=""><div dir="auto" class=""><div class=""><br class=""><br class=""><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Le dim. 22 août 2021 07 h 45, Neil Young via gstreamer-devel <<a href="mailto:gstreamer-devel@lists.freedesktop.org" target="_blank" rel="noreferrer" class="">gstreamer-devel@lists.freedesktop.org</a>> a écrit :<br class=""></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word;line-break:after-white-space" class="">Finally giving up on this. Python, webrtcbin and H.264 offer - this does not work</div><div style="word-wrap:break-word;line-break:after-white-space" dir="auto" class=""></div></blockquote></div></div><div dir="auto" class=""><br class=""></div><div dir="auto" class="">Hi Neil, I'm sorry this did not work you and no one was available in your required delay to freely support you.</div><div dir="auto" class=""><br class=""></div><div dir="auto" class="">This answer is simply to state that this works for others, the webrtcbin and rtpbin pipeline are known to be difficult, but not broken (except for few missing webrtc features of course).</div><div dir="auto" class=""><br class=""></div><div dir="auto" class=""><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word;line-break:after-white-space" dir="auto" class=""><br class=""><div dir="auto" class=""><br class=""></div><div dir="auto" class=""><br class=""><div class=""><br class=""><blockquote type="cite" class=""><div class="">Am 21.08.2021 um 20:23 schrieb Neil Young <<a href="mailto:foreverneilyoung@googlemail.com" rel="noreferrer noreferrer" target="_blank" class="">foreverneilyoung@googlemail.com</a>>:</div><br class=""><div class=""><div style="word-wrap:break-word;line-break:after-white-space" class="">I'm hanging on this for a week now, and it seems so easy, but whatever I do, I can't make it work<div class=""><br class=""></div><div class="">My app is a Python GST app, running on 18.4. It supports two modes: "call" and "answer". In call mode the app immediately issues an H.264 or VP8 OFFER (depending on a setting). This works in 100 % of the cases. </div><div class=""><br class=""></div><div class="">What also works is when the app ANSWERs a VP8 offer. Just H.264 OFFERS are not working, even though the SDP answer looks good. I just don't get the video to remote.</div><div class=""><br class=""></div><div class="">My app works like so:</div><div class=""><br class=""></div><div class="">1) When the app has a connection to the signaling server it creates a webrtcbin object:</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-wrap" class=""><div class=""> <span style="color:#210de5;font-weight:bold" class="">def</span> <span style="color:#1200bb" class="">build_webrtcbin</span>(<span style="color:#ab3c11;font-style:italic" class="">self</span>):</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.webrtcbin <span style="color:#7f0055" class="">=</span> Gst.ElementFactory.make(<span style="color:#ba2500" class="">"webrtcbin"</span>)</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.webrtcbin.set_property(<span style="color:#ba2500" class="">"bundle-policy"</span>, <span style="color:#ba2500" class="">"max-bundle"</span>)</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.webrtcbin.set_property(<span style="color:#ba2500" class="">"stun-server"</span>, <span style="color:#ba2500" class="">"<a rel="noreferrer noreferrer" class="">stun://stun.l.google.com:19302</a>"</span>)</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.webrtcbin.connect(<span style="color:#d126d1" class="">'on-negotiation-needed'</span>, <span style="color:#7f0055;font-weight:bold" class="">self</span>.on_negotiation_needed)</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.webrtcbin.connect(<span style="color:#d126d1" class="">'on-ice-candidate'</span>, <span style="color:#7f0055;font-weight:bold" class="">self</span>.on_ice_candidate)</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.webrtcbin.connect(<span style="color:#d126d1" class="">'pad-added'</span>, <span style="color:#7f0055;font-weight:bold" class="">self</span>.on_pad_added)</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.webrtcbin.connect(<span style="color:#d126d1" class="">'notify::connection-state'</span>, <span style="color:#7f0055;font-weight:bold" class="">self</span>.on_connection_state)</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.webrtcbin.connect(<span style="color:#d126d1" class="">'notify::signaling-state'</span>, <span style="color:#7f0055;font-weight:bold" class="">self</span>.on_signaling_state)</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.webrtcbin.connect(<span style="color:#d126d1" class="">'notify::ice-connection-state'</span>, <span style="color:#7f0055;font-weight:bold" class="">self</span>.on_ice_connection_state)</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.webrtcbin.connect(<span style="color:#d126d1" class="">'notify::ice-gathering-state'</span>, <span style="color:#7f0055;font-weight:bold" class="">self</span>.on_ice_gathering_state)</div><br class=""><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.pipeline <span style="color:#7f0055" class="">=</span> Gst.Pipeline.new()</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.pipeline.add(<span style="color:#7f0055;font-weight:bold" class="">self</span>.webrtcbin)</div><div class=""><br class=""></div><div class="">Nothing special I guess.</div><br class=""></div></div><div style="background-color:rgb(255,255,255);line-height:21px" class=""><div style="font-family:Verdana;white-space:normal" class="">2) When the SDP OFFER comes in, the app does this:</div><div style="font-family:Verdana;white-space:normal" class=""><br class=""></div><div style="font-family:Verdana;white-space:normal" class="">2a) It starts the H.264 pipeline with `start_pipeline`. </div><div style="font-family:Verdana;white-space:normal" class="">2b) It emits the remote description to the local webrtcbin</div><div class=""><div style="font-family:"Fira Code",Menlo,Monaco,"Courier New",monospace,Menlo,Monaco,"Courier New",monospace;white-space:pre-wrap;line-height:21px" class=""><span style="color:#7f0055;font-weight:bold" class=""><br class=""></span></div><div style="font-family:"Fira Code",Menlo,Monaco,"Courier New",monospace,Menlo,Monaco,"Courier New",monospace;white-space:pre-wrap;line-height:21px" class=""><span style="color:#7f0055;font-weight:bold" class="">self</span>.webrtcbin.emit(<span style="color:#d126d1" class="">'set-remote-description'</span>, desc, promise)</div><div style="font-family:"Fira Code",Menlo,Monaco,"Courier New",monospace,Menlo,Monaco,"Courier New",monospace;white-space:pre-wrap;line-height:21px" class=""><br class=""></div><div style="line-height:21px" class="">2c) It creates an answer calling `self.create_answer()`</div><div style="line-height:21px" class=""><br class=""></div><div style="line-height:21px" class=""><div style="font-family:"Fira Code",Menlo,Monaco,"Courier New",monospace,Menlo,Monaco,"Courier New",monospace;line-height:21px;white-space:pre-wrap" class=""><div class=""> <span style="color:#210de5;font-weight:bold" class="">def</span> <span style="color:#1200bb" class="">create_answer</span>(<span style="color:#ab3c11;font-style:italic" class="">self</span>):</div><div class=""> promise <span style="color:#7f0055" class="">=</span> Gst.Promise.new_with_change_func(<span style="color:#7f0055;font-weight:bold" class="">self</span>.on_answer_created, <span style="color:#7f0055;font-weight:bold" class="">self</span>.webrtcbin, <span style="color:#0a9dff" class="">None</span>)</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.webrtcbin.emit(<span style="color:#d126d1" class="">'create-answer'</span>, <span style="color:#0a9dff" class="">None</span>, promise)</div><div style="line-height:21px" class=""><div class=""> </div><div class=""><span style="color:#210de5;font-weight:bold" class=""> def</span> <span style="color:#1200bb" class="">on_answer_created</span>(<span style="color:#ab3c11;font-style:italic" class="">self</span>, <span style="color:#ab3c11;font-style:italic" class="">promise</span>, <span style="color:#ab3c11;font-style:italic" class="">_</span>, <span style="color:#ab3c11;font-style:italic" class="">__</span>):</div><div class=""> <span style="color:#d126d1" class="">''' Local WebRTC stack has created an answer '''</span></div><div class=""> promise.wait()</div><div class=""> reply <span style="color:#7f0055" class="">=</span> promise.get_reply()</div><div class=""> answer <span style="color:#7f0055" class="">=</span> reply.get_value(<span style="color:#d126d1" class="">'answer'</span>)</div><div class=""> promise <span style="color:rgb(127,0,85)" class="">=</span> Gst.Promise.new()</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.webrtcbin.emit(<span style="color:#d126d1" class="">'set-local-description'</span>, answer, promise)</div><div class=""> promise.interrupt()</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.send_sdp_answer(answer) # Forwarding the answer to remote using the signaling server</div></div></div></div><div style="font-family:"Fira Code",Menlo,Monaco,"Courier New",monospace,Menlo,Monaco,"Courier New",monospace;white-space:pre-wrap;line-height:21px" class=""><br class=""></div></div><div style="font-family:Verdana;white-space:normal" class="">Observations so far:</div><div style="font-family:Verdana;white-space:normal" class=""><br class=""></div><div style="font-family:Verdana;white-space:normal" class="">- It doesn't work if I don't set a payload-type which matches a payload type carried by the OFFERER or if I omit the payload-type. With ALL browsers it is sufficient to use the payload-type carried by the first H.264 element in the OFFER</div><div style="font-family:Verdana;white-space:normal" class="">- It is not necessary to set the `profile-level-id`</div><div style="font-family:Verdana;white-space:normal" class=""><br class=""></div><div style="font-family:Verdana;white-space:normal" class="">The best result I can achieve with this flow is a spinning wheel in the browser. No video.</div><div style="font-family:Verdana;white-space:normal" class=""><br class=""></div><div style="font-family:Verdana;white-space:normal" class="">BUT: </div><div style="font-family:Verdana;white-space:normal" class=""><br class=""></div><div style="font-family:Verdana;white-space:normal" class="">When I issue a call to `start_pipeline` somewhere shortly after the start (I use the moment, when I have a connection with the signaling server for this) with _exactly_the_same_payload_type_that_will_match_later_, I 100% have a video...</div><div style="font-family:Verdana;white-space:normal" class=""><br class=""></div><div style="font-family:Verdana;white-space:normal" class="">This MUST be a side effect, because the log complains about the second `start_pipeline` (warnings, it seems to ignore it).... But it works. Of course this is not a working solution, because</div><div style="font-family:Verdana;white-space:normal" class=""><br class=""></div><div style="font-family:Verdana;white-space:normal" class="">a) I would have to know the payload-type beforehand (it doesn't work if I use another payload-type in the first start)</div><div style="font-family:Verdana;white-space:normal" class="">b) I would have to parse the incoming SDP for the first H.264 (which is doable)</div><div style="font-family:Verdana;white-space:normal" class=""><br class=""></div><div style="font-family:Verdana;white-space:normal" class="">What am I doing wrong?</div><div style="font-family:Verdana;white-space:normal" class=""><br class=""></div><div style="font-family:Verdana;white-space:normal" class=""><br class=""></div><div style="font-family:Verdana;white-space:normal" class=""><br class=""></div><div style="font-family:Verdana;white-space:normal" class=""><br class=""></div><div style="font-family:Verdana;white-space:normal" class=""><div style="font-family:"Fira Code",Menlo,Monaco,"Courier New",monospace,Menlo,Monaco,"Courier New",monospace;line-height:21px;white-space:pre-wrap" class=""><div class=""> <span style="color:#210de5;font-weight:bold" class="">def</span> <span style="color:#1200bb" class="">start_pipeline</span>(<span style="color:#ab3c11;font-style:italic" class="">self</span>, <span style="color:#ab3c11;font-style:italic" class="">payload_type</span>):</div><div class=""> videotestsrc <span style="color:#7f0055" class="">=</span> Gst.ElementFactory.make(<span style="color:#ba2500" class="">"videotestsrc"</span>, <span style="color:#ba2500" class="">"videotestsrc"</span>)</div><div class=""> videotestsrc.set_property(<span style="color:#ba2500" class="">"is-live"</span>, <span style="color:#0a9dff" class="">True</span>)</div><div class=""> videotestsrc.set_property(<span style="color:#ba2500" class="">"pattern"</span>, <span style="color:#ba2500" class="">"smpte"</span>)</div><br class=""><div class=""> videotestsrc_caps <span style="color:#7f0055" class="">=</span> Gst.caps_from_string(<span style="color:#ba2500" class="">"video/x-raw, width=1280, height=720"</span>)</div><div class=""> </div><div class=""> videotestsrc_caps_filter <span style="color:#7f0055" class="">=</span> Gst.ElementFactory.make(<span style="color:#ba2500" class="">"capsfilter"</span>)</div><div class=""> videotestsrc_caps_filter.set_property(<span style="color:#ba2500" class="">"caps"</span>, videotestsrc_caps)</div><br class=""><div class=""> videoconvert <span style="color:#7f0055" class="">=</span> Gst.ElementFactory.make(<span style="color:#ba2500" class="">"videoconvert"</span>, <span style="color:#ba2500" class="">"videoconvert"</span>)</div><br class=""><div class=""> x264enc <span style="color:#7f0055" class="">=</span> Gst.ElementFactory.make(<span style="color:#ba2500" class="">"x264enc"</span>, <span style="color:#ba2500" class="">"x264enc"</span>)</div><div class=""> x264enc.set_property(<span style="color:#ba2500" class="">"threads"</span>, <span style="color:#ff8000" class="">4</span>)</div><div class=""> </div><div class=""> x264enc_caps <span style="color:#7f0055" class="">=</span> Gst.caps_from_string(<span style="color:#ba2500" class="">"video/x-h264, profile=constrained-baseline"</span>)</div><br class=""><div class=""> x264enc_caps_filter <span style="color:#7f0055" class="">=</span> Gst.ElementFactory.make(<span style="color:#ba2500" class="">"capsfilter"</span>)</div><div class=""> x264enc_caps_filter.set_property(<span style="color:#ba2500" class="">"caps"</span>, x264enc_caps)</div><br class=""><div class=""> rtph264pay <span style="color:#7f0055" class="">=</span> Gst.ElementFactory.make(<span style="color:#ba2500" class="">"rtph264pay"</span>, <span style="color:#ba2500" class="">"rtph264pay"</span>)</div><div class=""> rtph264pay.set_property(<span style="color:#ba2500" class="">"config-interval"</span>, <span style="color:#098eff;font-weight:bold" class="">-</span><span style="color:#ff8000" class="">1</span>)</div><div class=""> rtph264pay.set_property(<span style="color:#ba2500" class="">"aggregate-mode"</span>, <span style="color:#ba2500" class="">"zero-latency"</span>)</div><br class=""><div class=""> rtph264pay_caps <span style="color:#7f0055" class="">=</span> Gst.caps_from_string(<span style="color:#ba2500" class="">"application/x-rtp, media=video, encoding-name=H264"</span>)</div><div class=""> rtph264pay_caps.set_value(<span style="color:#ba2500" class="">"payload"</span>, payload_type)</div><br class=""><div class=""> rtph264pay_caps_filter <span style="color:#7f0055" class="">=</span> Gst.ElementFactory.make(<span style="color:#ba2500" class="">"capsfilter"</span>)</div><div class=""> rtph264pay_caps_filter.set_property(<span style="color:#ba2500" class="">"caps"</span>, rtph264pay_caps)</div><br class=""><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.pipeline.add(videotestsrc)</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.pipeline.add(videotestsrc_caps_filter)</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.pipeline.add(videoconvert)</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.pipeline.add(x264enc)</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.pipeline.add(x264enc_caps_filter)</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.pipeline.add(rtph264pay)</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.pipeline.add(rtph264pay_caps_filter)</div><br class=""><div class=""> <a href="http://gst.element.link/" rel="noreferrer noreferrer" target="_blank" class="">Gst.Element.link</a>(videotestsrc, videotestsrc_caps_filter)</div><div class=""> <a href="http://gst.element.link/" rel="noreferrer noreferrer" target="_blank" class="">Gst.Element.link</a>(videotestsrc_caps_filter, videoconvert)</div><div class=""> <a href="http://gst.element.link/" rel="noreferrer noreferrer" target="_blank" class="">Gst.Element.link</a>(videoconvert, x264enc)</div><div class=""> <a href="http://gst.element.link/" rel="noreferrer noreferrer" target="_blank" class="">Gst.Element.link</a>(x264enc, x264enc_caps_filter)</div><div class=""> <a href="http://gst.element.link/" rel="noreferrer noreferrer" target="_blank" class="">Gst.Element.link</a>(x264enc_caps_filter, rtph264pay)</div><div class=""> <a href="http://gst.element.link/" rel="noreferrer noreferrer" target="_blank" class="">Gst.Element.link</a>(rtph264pay, rtph264pay_caps_filter)</div><div class=""> <a href="http://gst.element.link/" rel="noreferrer noreferrer" target="_blank" class="">Gst.Element.link</a>(rtph264pay_caps_filter, <span style="color:#7f0055;font-weight:bold" class="">self</span>.webrtcbin)</div><div class=""> <span style="color:#7f0055;font-weight:bold" class="">self</span>.pipeline.set_state(Gst.State.PLAYING)</div><br class=""></div></div></div></div></div></blockquote></div><br class=""></div></div></blockquote></div></div></div> </div></blockquote></div><br class=""></div></div></div></blockquote></div><br class=""></div></blockquote></div></div></div> </div></blockquote></div><br class=""></div></div></div></blockquote></div><br class=""></div></div></div></blockquote></div><br class=""></body></html>