Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754880AbaJ1PeD (ORCPT ); Tue, 28 Oct 2014 11:34:03 -0400 Received: from mailapp01.imgtec.com ([195.59.15.196]:60403 "EHLO mailapp01.imgtec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750925AbaJ1Pd7 (ORCPT ); Tue, 28 Oct 2014 11:33:59 -0400 Message-ID: <544FB763.6040904@imgtec.com> Date: Tue, 28 Oct 2014 15:33:55 +0000 From: Qais Yousef User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.8.0 MIME-Version: 1.0 To: Lars-Peter Clausen , Clemens Ladisch , CC: Arnd Bergmann , Greg Kroah-Hartman , , , Neil Jones Subject: Re: [PATCH 00/11] Add AXD Audio Processing IP driver References: <1414495589-8579-1-git-send-email-qais.yousef@imgtec.com> <544F8439.4080402@ladisch.de> <544F97A4.7080209@imgtec.com> <544FAE35.4000509@metafoo.de> In-Reply-To: <544FAE35.4000509@metafoo.de> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.154.94] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/28/2014 02:54 PM, Lars-Peter Clausen wrote: > On 10/28/2014 02:18 PM, Qais Yousef wrote: >> On 10/28/2014 11:55 AM, Clemens Ladisch wrote: >>> Qais Yousef wrote: >>>> AXD Audio Processing IP performs audio decoding, encoding, mixing, >>>> equalisation, >>>> synchronisation and playback. >>> What exactly do you mean with "synchronisation" and "playback"? >> >> Synchronisation refers to accurate audio playout relative to a master >> clock source including compensation of drift between the master clock >> source and the playout clock of the audio hardware. Hence allowing >> synchronised audio playout across multiple independent devices. >> >> Playback simple refers to the fact that AXD is capable of managing audio >> playout hardware like I2S and SPDIF interfaces. >> >> >>>> It doesn't fit in alsa subsystem but I Cced them to confirm. >>> ... because those two words sound like something that a sound card >>> could do. >> >> The problem mainly stems from the fact that we take a variety of >> compressed audio as input and we could perform audio encoding. The >> problem with the compressed audio is that the range of decoders and >> configuration supported in alsa is limited and there's no support for >> taking raw pcm and producing compressed output. I'm not an expert on >> alsa but when I looked it looked like there's more infra structure >> required. >> >> [...] > > This doesn't sound to different from any of the other supported audio > DSPs. ALSA seems to have 95% of what you need. And the missing 5% is > probably stuff that is not specific to your hardware but rather > something that other hardware will need as well. The framework is not > set in stone you can make modifications and add the features that are > missing to make your hardware work. > > E.g. look at sound/soc/intel/ for an example of a audio DSP. > > No integrating this into ALSA will quite likely result in a quite > messy situation for you on the long run. > > - Lars > > > OK thanks for the reference. To be honest it felt like 15-20% of the features are missing but I'll need to look at the specifics and judge/estimate better. Thanks, Qais -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/