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 X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3AEABC433DF for ; Thu, 23 Jul 2020 15:56:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0913320792 for ; Thu, 23 Jul 2020 15:56:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595519779; bh=GcS2kAU29xEZ0jnjZv+lYshFkwhHH/EsbplOO3bG05k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=pCGRijgf0s1UolMpXYk9XSTlCk5e4ZmlQkPhPYZHWNHwwTgYzT8I/Ugm19dFyo1Wz 8b9vq35dL/5mKnZm1zw2e9Td9U63uERUBlrToTIUPHYjmImZvMKHZMB3G2yPMY8Oe4 LI0KXDM0BZxv4+6o3Z2sM2NCPyhraNJNnzyuha0A= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729666AbgGWP4R (ORCPT ); Thu, 23 Jul 2020 11:56:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:34018 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726761AbgGWP4R (ORCPT ); Thu, 23 Jul 2020 11:56:17 -0400 Received: from localhost (unknown [122.171.202.192]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 15CBB2071A; Thu, 23 Jul 2020 15:56:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595519777; bh=GcS2kAU29xEZ0jnjZv+lYshFkwhHH/EsbplOO3bG05k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=0oyzTe84hn6Vi+wGOvEXcgLfAzirXbWQJ19VhKfJoYDqWTBUsvmi/Ur6HbDyxfBgK OjloT3wXweREikgFKAWxvNvD+ia6USsUei/xHKb5GqTHWIOy3LVZBSvWWni91il77j d+RHqZ7QrGeIFiwWbZXrK3MKpywI/hUmjwsAht0I= Date: Thu, 23 Jul 2020 21:26:12 +0530 From: Vinod Koul To: Takashi Iwai Cc: Srinivas Kandagatla , broonie@kernel.org, perex@perex.cz, tiwai@suse.com, lgirdwood@gmail.com, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, ckeepax@opensource.cirrus.com Subject: Re: [RFC PATCH v2 0/6] ALSA: compress: add support to change codec profile in gapless playback Message-ID: <20200723155612.GC12965@vkoul-mobl> References: <20200721170007.4554-1-srinivas.kandagatla@linaro.org> <20200723130522.GB12965@vkoul-mobl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 23-07-20, 15:17, Takashi Iwai wrote: > On Thu, 23 Jul 2020 15:05:22 +0200, > Vinod Koul wrote: > > > > On 23-07-20, 14:38, Takashi Iwai wrote: > > > On Tue, 21 Jul 2020 19:00:01 +0200, > > > Srinivas Kandagatla wrote: > > > > > > > > For gapless playback it is possible that each track can have different > > > > codec profile with same decoder, for example we have WMA album, > > > > we may have different tracks as WMA v9, WMA v10 and so on > > > > Or if DSP's like QDSP have abililty to switch decoders on single stream > > > > for each track, then this call could be used to set new codec parameters. > > > > > > > > Existing code does not allow to change this profile while doing gapless > > > > playback. > > > > > > > > This patchset adds new SNDRV_COMPRESS_SET_CODEC_PARAMS IOCTL along with > > > > flags in capablity structure to allow userspace to set this new > > > > parameters required which switching codec profile, either for gapless > > > > or cross fade usecase. > > > > > > One idea that came up at the previous audio conference regarding this > > > implementation was to just allow SET_PARAMS during the stream is > > > running (only if the driver sets the capability) instead of > > > introducing yet a new ioctl and an ops. > > > Would it make sense? > > > > That does sound good but only issue would be that we need to somehow > > mark/document that buffer info is useless and would be discarded, how do > > we do that? > > Yes, the buffer and no_wake_mode can be ignored in the gapless > re-setup. Is your concern only about the documentation? Or something > else needs to be changed significantly? It's a new scheme in anyway, > so the documentation update is required... My concern is potential abuse of API down the road, if you feel it is okay, I am okay with the proposal Thanks -- ~Vinod