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=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 6CBC2C433E3 for ; Thu, 23 Jul 2020 13:17:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 406E6208E4 for ; Thu, 23 Jul 2020 13:17:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729345AbgGWNRb (ORCPT ); Thu, 23 Jul 2020 09:17:31 -0400 Received: from mx2.suse.de ([195.135.220.15]:51088 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728426AbgGWNRa (ORCPT ); Thu, 23 Jul 2020 09:17:30 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 07FB5AB55; Thu, 23 Jul 2020 13:17:37 +0000 (UTC) Date: Thu, 23 Jul 2020 15:17:28 +0200 Message-ID: From: Takashi Iwai To: Vinod Koul 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 In-Reply-To: <20200723130522.GB12965@vkoul-mobl> References: <20200721170007.4554-1-srinivas.kandagatla@linaro.org> <20200723130522.GB12965@vkoul-mobl> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.3 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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... thanks, Takashi > > > I have no big objection to add a new ioctl if other people agree, > > though. > > > > > > thanks, > > > > Takashi > > -- > ~Vinod >