From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: mail.toke.dk; spf=pass (mailfrom) smtp.mailfrom=irif.fr (client-ip=2001:660:3301:8000::1:2; helo=korolev.univ-paris7.fr; envelope-from=jch@irif.fr; receiver=) Received: from korolev.univ-paris7.fr (korolev.univ-paris7.fr [IPv6:2001:660:3301:8000::1:2]) by mail.toke.dk (Postfix) with ESMTPS id 44223826D71 for ; Tue, 6 Apr 2021 14:57:53 +0200 (CEST) Received: from mailhub.math.univ-paris-diderot.fr (mailhub.math.univ-paris-diderot.fr [81.194.30.253]) by korolev.univ-paris7.fr (8.14.4/8.14.4/relay1/82085) with ESMTP id 136Cvoc8023145; Tue, 6 Apr 2021 14:57:50 +0200 Received: from mailhub.math.univ-paris-diderot.fr (localhost [127.0.0.1]) by mailhub.math.univ-paris-diderot.fr (Postfix) with ESMTP id 4F7A2BB6B5; Tue, 6 Apr 2021 14:57:50 +0200 (CEST) X-Virus-Scanned: amavisd-new at math.univ-paris-diderot.fr Received: from mailhub.math.univ-paris-diderot.fr ([127.0.0.1]) by mailhub.math.univ-paris-diderot.fr (mailhub.math.univ-paris-diderot.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id noE3iFGXBLQY; Tue, 6 Apr 2021 14:57:48 +0200 (CEST) Received: from pirx.irif.fr (unknown [78.194.40.74]) (Authenticated sender: jch) by mailhub.math.univ-paris-diderot.fr (Postfix) with ESMTPSA id 0F17BBB6B3; Tue, 6 Apr 2021 14:57:48 +0200 (CEST) Date: Tue, 06 Apr 2021 14:57:47 +0200 Message-ID: <87zgybsh84.wl-jch@irif.fr> From: Juliusz Chroboczek To: Alexandre IOOSS In-Reply-To: <228e92c1-d1f7-bc6d-4f44-c9cfd28f0096@crans.org> References: <228e92c1-d1f7-bc6d-4f44-c9cfd28f0096@crans.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) Emacs/27.1 Mule/6.0 MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.7 (korolev.univ-paris7.fr [194.254.61.138]); Tue, 06 Apr 2021 14:57:50 +0200 (CEST) X-Miltered: at korolev with ID 606C5ACE.000 by Joe's j-chkmail (http : // j-chkmail dot ensmp dot fr)! X-j-chkmail-Enveloppe: 606C5ACE.000 from mailhub.math.univ-paris-diderot.fr/mailhub.math.univ-paris-diderot.fr/null/mailhub.math.univ-paris-diderot.fr/ X-j-chkmail-Score: MSGID : 606C5ACE.000 on korolev.univ-paris7.fr : j-chkmail score : . : R=. U=. O=. B=0.000 -> S=0.000 X-j-chkmail-Status: Ham Message-ID-Hash: QD6DUDKJY6ZDJKCVABBEUWXH37S67B6H X-Message-ID-Hash: QD6DUDKJY6ZDJKCVABBEUWXH37S67B6H X-MailFrom: jch@irif.fr X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: galene@lists.galene.org X-Mailman-Version: 3.3.4 Precedence: list Subject: [Galene] Re: Building a streaming gateway for =?iso-8859-1?q?Gal=E8ne?= List-Id: =?utf-8?q?Gal=C3=A8ne_videoconferencing_server_discussion_list?= Archived-At: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: > For the past two weeks I have been working on streaming from a > broadcasting software such as OBS-Studio (that uses FFMpeg) to Gal=E8ne. This would be a great addition! We have quite a few users that use OBS, and, as you mention, going through the v4l virtual camera has some disadvantages. > 0. Using OBS Virtual v4l2 camera, but it is not portable and has audio > sync issues. > 1. Streaming to a gateway that will initiate the WebRTC session with Gal= =E8ne. > 2. Implement WebRTC support in OBS-Studio as an output plugin. I would tend to agree, (1) is probably the best solution, since it avoids bloating either Gal=E8ne or OBS. > Last week I tried to implement a gateway using GStreamer webrtcbin > plugin, . Although I am able > to stream to Gal=E8ne, I observe video drops. I am circumventing the issue > by forcing the VP8 encoder to insert a keyframe every 5 frames, but that > seems a terrible hack. I'll have a look at your code as soon as I have some time. In the meantime, there are three things that you need to do: 1. send periodic RTCP Sender Reports with accurate NTP times; 2. react to RTCP PLI packets by inserting a keyframe; 3. react to RTCP NACK packets by resending the packets listed in the NACK. (1) is essential for proper lipsynch. (2) is what allows a stream to recover after a catastrophic loss event. (3) is what allows a stream to recover rapidly after moderate amounts of loss. > Right now [...] I don't know if I should... I'll have a look, think it over, then get back to you. -- Juliusz