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.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (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 28D48C001DF for ; Wed, 2 Aug 2023 12:10:33 +0000 (UTC) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=n0nVo96Y; dkim-atps=neutral Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4RG9m71vsWz3d8K for ; Wed, 2 Aug 2023 22:10:31 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20201202 header.b=n0nVo96Y; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=kernel.org (client-ip=139.178.84.217; helo=dfw.source.kernel.org; envelope-from=broonie@kernel.org; receiver=lists.ozlabs.org) Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4RG9kt69Cmz3cRJ for ; Wed, 2 Aug 2023 22:09:26 +1000 (AEST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D402D61926; Wed, 2 Aug 2023 12:09:23 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A7BCDC433C8; Wed, 2 Aug 2023 12:09:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1690978163; bh=M5e9aIt4zB+xazIlQzHD++KNXR0lBSq5lPpPZBlFnnU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=n0nVo96YwWrmpCF4FJWiUwGfROiwCepHz2+sCu2OSN3CVI7R58tLGqYicwk4YYKOg +NyLJzHU9dFDb2Ho6UPuP2IEP/c/D0cJo7dHvPkGv/B50Ta5mZBFLUrrx0aC9/XNWi +t/sdjYvpddoKhGi/JXjdc+frbE7nFrY66eu014qVGygZQPEEgKavljf8ltRC6P5Nq Xl3zKTbG64yhtVO+lK7S6RXM3ey01oWUYp+6GBs47b5d74fGfCwBb2ahJbqV9qozKI DnSeTdBh7Y9dCBVGiTCZq9YuojTjQKdr2+orJcAcMbvj7a7mpqrt05719eGZTT2qOk sgy/jEHSfCbYA== Date: Wed, 2 Aug 2023 13:09:16 +0100 From: Mark Brown To: Shengjiu Wang Subject: Re: [RFC PATCH v2 0/7] Add audio support in v4l2 framework Message-ID: References: <1690265540-25999-1-git-send-email-shengjiu.wang@nxp.com> <47d66c28-1eb2-07f5-d6f9-779d675aefe8@xs4all.nl> <87il9xu1ro.wl-tiwai@suse.de> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="s7JwRvdQJYqkq6dD" Content-Disposition: inline In-Reply-To: X-Cookie: Humpty Dumpty was pushed. X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: nicoleotsuka@gmail.com, alsa-devel@alsa-project.org, lgirdwood@gmail.com, Xiubo.Lee@gmail.com, Takashi Iwai , linux-kernel@vger.kernel.org, Shengjiu Wang , tiwai@suse.com, linux-media@vger.kernel.org, tfiga@chromium.org, Hans Verkuil , linuxppc-dev@lists.ozlabs.org, sakari.ailus@iki.fi, perex@perex.cz, mchehab@kernel.org, festevam@gmail.com, m.szyprowski@samsung.com Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" --s7JwRvdQJYqkq6dD Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Aug 02, 2023 at 08:02:29PM +0800, Shengjiu Wang wrote: > On Wed, Aug 2, 2023 at 7:22=E2=80=AFPM Takashi Iwai wrote: > > Well, I personally don't mind to have some audio capability in v4l2 > > layer. But, the only uncertain thing for now is whether this is a > > must-have or not. > Thanks, I am also not sure about this. I am also confused that why > there is no m2m implementation for audio in the kernel. Audio also > has similar decoder encoder post-processing as video. This is the thing where we've been trying to persuade people to work on replacing DPCM with full componentisation for about a decade now but nobody's had time other than Morimoto-san who's been chipping away at making everything component based for a good chunk of that time. One trick is that we don't just want this to work for things that are memory to memory, we also want things where there's a direct interconnect that bypasses memory for off-SoC case. > The reason why I select to extend v4l2 for such audio usage is that v4l2 > looks best for this audio m2m implementation. v4l2 is designed for m2m > usage. if we need implement another 'route', I don't think it can do be= tter > that v4l2. > I appreciate that someone can share his ideas or doable solutions. > And please don't ignore my request, ignore my patch. There's a bunch of presentations Lars-Peter did at ELC some considerable time ago about this. --s7JwRvdQJYqkq6dD Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmTKR2sACgkQJNaLcl1U h9DDTwf/Xps9jJnts1SAD46EJPtve2N9sezS1xZvZgz0pluqjz+vDEyh+ediLcCy uoiOc/xZz8Odde64unpb8nKuJzfH8hwdn4JFEMc9capaRijhM9iYxSNlDK6p0wil AX82WXjRdrxyPbNJQgqYehJTbcydxIbewfCqG0ryrG+NeiAPZwR/p1IrCVzBrCZ5 E5+J4oQCAB7li51EuyZuihiImeoDS8LMbPJ5ciHXbhnXyIZaw8AvxTEz9d9llUl8 36hbfxrM24rlJDE16kRco/zHvMkK38W6fubovlGudON8xDoUBFZIPP3SWa5TRy7n j3xcxiC0N3R2xWsDWKC3p7rK6OoiYQ== =0Tfg -----END PGP SIGNATURE----- --s7JwRvdQJYqkq6dD--