From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Re: How to tell user level hardware not support a certain format in a certain sample rate Date: Mon, 02 Mar 2009 15:12:40 +0100 Message-ID: References: <4e090d470902222302g16a99f5dq77d0d40f6cba855e@mail.gmail.com> <4e090d470903020604h27ce2ce8l47f996edc9764ada@mail.gmail.com> Mime-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by alsa0.perex.cz (Postfix) with ESMTP id 5A4EC2414C for ; Mon, 2 Mar 2009 15:12:40 +0100 (CET) In-Reply-To: <4e090d470903020604h27ce2ce8l47f996edc9764ada@mail.gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: Richard Zhao Cc: alsa-devel List-Id: alsa-devel@alsa-project.org At Mon, 2 Mar 2009 22:04:04 +0800, Richard Zhao wrote: > > 2009/2/23 Richard Zhao : > > Hi, > > > > runtime->hw.rates and runtime->hw.formats indicate the rate and > > formats hardware can support, so the user level plugins can > > auto-convert the audio data. But hardware may not support a certain > > combin of sample rate and format, and will cause hw_parm fail. In such > > case, plugin auto-convert will not work. > > How can I let userlevel know the failure conbin, so let auto-convert work? > > > > Thanks > > Richard > > > > Anybody can do me a favor please? Could you be more specific, e.g. test cases with numbers? There are some known problems with the configuration space reduction, and I think your problem is one of them, though. Basically, the config space is reduced one after one for each snd_pcm_hw_params_refine(), and the existence of a singular point makes hard to pick up the right point. If the problem is such one, currently there is no elegant solution. Takashi