From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 714BCD116F6 for ; Tue, 2 Dec 2025 15:40:46 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vQSU7-0006Qu-0G; Tue, 02 Dec 2025 10:40:11 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vQSU1-0006Pc-PL for qemu-devel@nongnu.org; Tue, 02 Dec 2025 10:40:07 -0500 Received: from kylie.crudebyte.com ([5.189.157.229]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vQSU0-0006gx-4b for qemu-devel@nongnu.org; Tue, 02 Dec 2025 10:40:05 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=crudebyte.com; s=kylie; h=Content-Type:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Content-ID:Content-Description; bh=w9e8SrckWJ5ye1v5ZLPUDemAk1WzOrh3dExIt+YNI9Q=; b=PQdlVaWMTvG2sTaqoCfaB2IYd7 dAfguWuRWzbVzqn0Y05Wp/CxBLTWNrxVIQkh3OKyZcVk+7N+C31ynRebxiCDMoH7TFw0rOjOJeXNW lGT+iCzLZPBo17OSiu0BOOqstpPs6w2ZOll33E9D7/Nk/oLgio/cEjevtcH5JByloA2cxbmamb00n Ucf1soJt7W8bCFEOSnm3yUkj5NwemVqvKAEPpLpjIdwhpTdaQbJ3HYK9d23fj0qgYJDeEZALKo/Xd YVi5HwTYguoe294dyPdBb3jEzs+AqqN2lV2Djmp7+44dW+OWdzXWFZvDCoQ+nmVc54QHUnGuyhar2 STDty95GygkDV7SjiMIG5qu0NLUfXm2fNZj6CYz+410J87l+FDt0RDz+Gt4Yorwm1vj8kH5UpRFSw 7oOmnYIleqSPkS4CubEi+WTQXgvmzJkn3hzR++jSE1YhfEmB30f0pJnwU3pVhWBZWk0ixksgI4LzX b8Qj6CTAXC3bzJT+emNV27B6GeCz9Q7slfZsmZcjd3/2mBHoNUymckodOmGc07cEyOAqlRt8P/N4t XXhWVM7oegxEubLbZqus61DQTTTcCFcBz0A3lUWe0NXrNMp4yPtzcjHsn3PglBENLTTQNeufloucw paoyNM91AbpgCtu2o7mtdPFBqEw28KpGyChVn5SsY=; From: Christian Schoenebeck To: qemu-devel@nongnu.org Cc: Geoffrey McRae , BALATON Zoltan , Paolo Bonzini , Alexandre Ratchov , qemu-devel@nongnu.org, Gerd Hoffmann , Thomas Huth , Akihiko Odaki , dirty.ice.hu@gmail.com, Philippe =?UTF-8?B?TWF0aGlldS1EYXVkw6k=?= , Volker =?UTF-8?B?UsO8bWVsaW4=?= , =?UTF-8?B?TWFyYy1BbmRyw6k=?= Lureau Subject: Re: [RFC 00/24] audio: add GStreamer backend Date: Tue, 02 Dec 2025 16:39:44 +0100 Message-ID: <47697442.fMDQidcC6G@weasel> In-Reply-To: References: <20251201112309.4163921-1-marcandre.lureau@redhat.com> <12d3c2d298399c0935edee8caa3e52aa@hostfission.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Received-SPF: pass client-ip=5.189.157.229; envelope-from=qemu_oss@crudebyte.com; helo=kylie.crudebyte.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Tuesday, 2 December 2025 15:14:48 CET Marc-Andr=C3=A9 Lureau wrote: > On Tue, Dec 2, 2025 at 5:26=E2=80=AFPM Geoffrey McRae wrote: > > On 2025-12-02 23:44, Marc-Andr=C3=A9 Lureau wrote: > > > Hi Geoffrey > > >=20 > > > On Tue, Dec 2, 2025 at 4:31=E2=80=AFPM Geoffrey McRae > > >=20 > > > wrote: > > >> The PipeWire and PulseAudio backends are used by a large number of > > >> users > > >> in the VFIO community. Removing these would be an enormous determent > > >> to > > >> QEMU. > > >=20 > > > They come with GStreamer pulse/pipe elements. > >=20 > > Yes, but through another layer of abstraction/complexity with no real > > benefit. >=20 > The benefit is that QEMU would not have to maintain 10 backends and > all the audio mixing/resampling. The QEMU code would be simpler and > more maintainable overall. GStreamer has a clear pipeline design, > better suited (optimized code etc) and you can easily modify the > pipeline settings. Nobody questions that it could reduce QEMU code. But it would move complexi= ty=20 to users by forcing them to add another layer. Many sound systems allow to = be=20 layered on top of other sound systems for a long time. But even only one=20 additional layer can make it very challenging to find out why you end up wi= th=20 a certain undesired setup like unexpected sample rate or bit depth (wrong U= SB=20 profile chosen of external audio device during USB enumeration? some defaul= t=20 plugin or mixer element of a layer doing resampling?), high latency=20 (additional buffers with higher size on some layer? where and why?) or even= =20 xruns. /Christian