From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-lb0-f173.google.com ([209.85.217.173]:38401 "EHLO mail-lb0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752863AbaFPOi5 (ORCPT ); Mon, 16 Jun 2014 10:38:57 -0400 Received: by mail-lb0-f173.google.com with SMTP id s7so2895163lbd.4 for ; Mon, 16 Jun 2014 07:38:56 -0700 (PDT) Message-ID: <539F017C.90408@gmail.com> Date: Mon, 16 Jun 2014 20:38:52 +0600 From: "Alexander E. Patrakov" MIME-Version: 1.0 To: Mauro Carvalho Chehab , Clemens Ladisch CC: Takashi Iwai , alsa-devel@alsa-project.org, Mauro Carvalho Chehab , Linux Media Mailing List Subject: Re: [alsa-devel] [PATCH 1/3] sound: Add a quirk to enforce period_bytes References: <1402762571-6316-1-git-send-email-m.chehab@samsung.com> <1402762571-6316-2-git-send-email-m.chehab@samsung.com> <539E9F25.7030504@ladisch.de> <20140616112110.3f509262.m.chehab@samsung.com> In-Reply-To: <20140616112110.3f509262.m.chehab@samsung.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: 16.06.2014 20:21, Mauro Carvalho Chehab wrote: > Both xawtv and tvtime use the same code for audio: > http://git.linuxtv.org/cgit.cgi/xawtv3.git/tree/common/alsa_stream.c > > There's an algorithm there that gets the period size form both the > capture and the playback cards, trying to find a minimum period that > would work properly for both. I don't see any adaptive resampler (similar to what module-loopback does in pulseaudio) there. Without that, or dynamically controlling the audio capture clock PLL in the tuner, xruns are unavoidable when transferring data between two unrelated cards. So, until any further evidence appears, I think it is a common bug in these audio codes. -- Alexander E. Patrakov