From bernard.aboba@gmail.com Thu Feb 15 07:34:08 2024 Return-Path: X-Original-To: rtcweb@ietfa.amsl.com Delivered-To: rtcweb@ietfa.amsl.com Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 06235C14CF1D for ; Thu, 15 Feb 2024 07:34:08 -0800 (PST) X-Virus-Scanned: amavisd-new at amsl.com X-Spam-Flag: NO X-Spam-Score: -7.097 X-Spam-Level: X-Spam-Status: No, score=-7.097 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_HI=-5, RCVD_IN_ZEN_BLOCKED_OPENDNS=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_KAM_HTML_FONT_INVALID=0.01, T_SCC_BODY_TEXT_LINE=-0.01] autolearn=ham autolearn_force=no Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com Received: from mail.ietf.org ([50.223.129.194]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id vND3SMoWBGL1 for ; Thu, 15 Feb 2024 07:34:07 -0800 (PST) Received: from mail-pg1-x52e.google.com (mail-pg1-x52e.google.com [IPv6:2607:f8b0:4864:20::52e]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id 60AE2C14F74E for ; Thu, 15 Feb 2024 07:34:07 -0800 (PST) Received: by mail-pg1-x52e.google.com with SMTP id 41be03b00d2f7-53fbf2c42bfso791868a12.3 for ; Thu, 15 Feb 2024 07:34:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1708011246; x=1708616046; darn=ietf.org; h=to:subject:message-id:date:from:mime-version:from:to:cc:subject :date:message-id:reply-to; bh=MBWWQtZa2yRmt5I5HQbs/EuV+lTk9lvMGA/aflYay08=; b=AkciIcvAZPCJ1w4NuglGlkuAb/8eJtVZ3N6zMzh/FgvQnz6dQjFb13E40redd7RLhS sgeS7vr4038bTga4dObAUH11q4knS4vecLN0ibg4W76r9sgQFMgHv3j/ekXYoyyRyNs/ GBV0HSkkTsyv9mYQeqSwG6qzg3RfLG4nlsYkjNqoiSar9gxJ1/gAGcH21L5mRBavlE1r kaoX/PTVSN3BGBhSjeX+1Jttfa5+3HBfRO0Xen90nu5Gobvj+Mo9L/sLrvz0b7pbDRWD 94kkpoWDAohxyDg+KaMJJjvao/Lw/Cv0jwauTtFsbs3OXuWsbuU/er/tLJclgX8fOHik ic1g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1708011246; x=1708616046; h=to:subject:message-id:date:from:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=MBWWQtZa2yRmt5I5HQbs/EuV+lTk9lvMGA/aflYay08=; b=JNf+Z9MaVwAkiI6UdiUa4Vqjj2wAERSHyqodsfDU7qb1cvOcR/nnEPeBIkczd9wT9z DC8RfoEzv+LP+jo3iGMT2xTaj0u3YL308wrRoPJA+68r+U3nupT+lH8nq/49RLfba7MV rKtE+90cHP10lqVJaqDKm94sUcm090Kfb3MA5C/bHICuP+e8xY2BOabQlzfjnsQPCD7O t8HJDDxWO7RkTSO/ijVqc8m1eGmkhvlEN4csAjLIGGc0y2mnKtxLFLuZp65MWKTxBC3d L387cu5BxcZk38bf0xNrjif+quulkKIa6XNXNemFFFUpcde/w5Tv6QpnrjcS1sTadT0O EG1w== X-Gm-Message-State: AOJu0Yy8s5ZilSUzmKV3ivS+VD8RKusP+oPAxh+8/ZxKyP01sEkz0lkt NzptIeJ9D7BW92cu3yb40+0Mjp3wkjG2Hr8wIFDIrnq95jKHrwi8VfDQXzO2oyd2T5dV4HcOOrs /K7VARfaQ20x5N7C462pEJGYec4F5uAXr/FxF4g== X-Google-Smtp-Source: AGHT+IFqqsYxi2rO+rKXWAR6TtUNksHGNv3lab3ELGPl5ssoYp/7oH5uIYKQE1xVeVSf9CUIn699r1stjVsLaPu1AAk= X-Received: by 2002:a17:90a:fe88:b0:298:c5db:a69 with SMTP id co8-20020a17090afe8800b00298c5db0a69mr1952100pjb.21.1708011246233; Thu, 15 Feb 2024 07:34:06 -0800 (PST) MIME-Version: 1.0 From: Bernard Aboba Date: Thu, 15 Feb 2024 07:33:54 -0800 Message-ID: To: RTCWeb IETF Content-Type: multipart/alternative; boundary="0000000000009aaebe06116d5b37" Archived-At: Subject: [rtcweb] JSEPbis: setCodecPreferences and send/receive-only codecs X-BeenThere: rtcweb@ietf.org X-Mailman-Version: 2.1.39 Precedence: list List-Id: Real-Time Communication in WEB-browsers working group list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 15 Feb 2024 15:34:08 -0000 --0000000000009aaebe06116d5b37 Content-Type: text/plain; charset="UTF-8" The W3C WEBRTC WG is currently dealing with Issues that have arisen with codecs that can only be sent or only received. As an example, there are browsers that can only receive H.265, but cannot send it (since they do not support encoding). Similarly, there are browsers that can send profiles of H.264 (and possibly H.265) that they cannot receive. The AVTCORE WG discussed the potential implications at the virtual interim meeting that occurred on February 13, 2024. Slides are here: https://docs.google.com/presentation/d/1gSOrVyB9jK32fynJUx2O-noJCvcTMQrvvFqlkFhfTV8/edit#slide=id.g268da8c9c26_0_145 Reviewing current implementations, it appears that there are some unexpected results and in many cases, that it is necessary to negotiate 2 m-lines, one for each direction. Discussion is currently ongoing in the following places: - AVTCORE: - WebRTC-HEVC Issue 22 - W3C WEBRTC WG: - w3c/webrtc-pc#2936 - w3c/webrtc-pc#2933 - w3c/webrtc-pc#2935 - w3c/webrtc-pc/#2888 --0000000000009aaebe06116d5b37 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
The W3C WEBRTC WG is currently dealing with Issues that ha= ve arisen with codecs that can only be sent or only received.=C2=A0 As an e= xample, there are browsers that can only receive H.265, but cannot send it = (since they do not support encoding).=C2=A0 Similarly, there are browsers t= hat can send profiles of H.264 (and possibly H.265) that they cannot receiv= e.=C2=A0

The AVTCORE WG discussed the potential implicat= ions at the virtual interim meeting that occurred on February 13, 2024.=C2= =A0 Slides are here:=C2=A0
=

Reviewing current implementations, it appears that ther= e are some unexpected results and in many cases, that it is necessary to ne= gotiate 2 m-lines, one for each direction.=C2=A0=C2=A0

=
Discussion is currently ongoing in the following places:=C2=A0
<= /div> --0000000000009aaebe06116d5b37--