From mboxrd@z Thu Jan 1 00:00:00 1970 From: Colin Guthrie Subject: Re: HDA: Problem with sound becoming corrupted Date: Thu, 10 Mar 2011 12:31:54 +0000 Message-ID: <4D78C4BA.4030005@colin.guthr.ie> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from summit.brent.tribalogic.net (brent.tribalogic.net [78.86.109.144]) by alsa0.perex.cz (Postfix) with ESMTP id D35C5244B9 for ; Thu, 10 Mar 2011 13:31:58 +0100 (CET) In-Reply-To: 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: Jean-Yves Avenard Cc: alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org 'Twas brillig, and Jean-Yves Avenard at 10/03/11 02:41 did gyre and gimble: > Hi > > On 10 March 2011 02:10, Colin Guthrie wrote: >> The problem is that the sound suddenly goes nuts and starts sounding >> awful. It's like some buffer pointer is just a little bit out for some >> reason. >> >> I can fix the issue by closing and reopening the PCM device (as I use >> PA, this is just a simple "pasuspender echo" away). > > >> >> The problem is very easy to reproduce - it happens about 20+ times a day >> to me - to the extent that I have added a panel launcher with the above fix. > > I have to raise my hand on this one too... It has puzzled me for a few > months now. > I had thought it was related to the new video/audio card I'm using a > GT220 , but this is about the same time I upgraded alsa. > > Every once in a while, the audio becomes slightly distorted. Voices > sounds like they are gargling with mouthwash while talking. > > Interestingly, it sounds the same for AC3 or DTS passthrough, it's > slightly corrupted, but not enough to break the AC3 stream from being > usable by the amp. > > However, closing the PCM device and re-opening it doesn't fix the > issue for me ; I need to reboot. > > This is seen with MythTV using ALSA directly (I wrote the audio code in MythTV) > > Few MythTV users have reported it, I can't explain what is causing it.. [Resend as I used the wrong email address the first time! Things have changed since the first one tho' Jean-Yves!] Sounds like it could be related indeed. I've been trying an older kernel today: 2.6.36.2 with: Advanced Linux Sound Architecture Driver Version 1.0.23. It worked well initially, but sadly I did get two occurrences of the problem so far (both specifically triggered rather than happening organically). This seems to tie in with my feeling that the problem started off as a nuisance but has gotten significantly more problematic with more recent kernels.... With a more recent kernel I can trigger it just changing the volume rapidly (which triggers a "bloop" noise). With this older kernel I still used this to trigger the problems, but it takes a while (it feels to take a lot longer than the newer kernel). I cannot discount this being a subjective comparison however. I'll look further. Col -- Colin Guthrie gmane(at)colin.guthr.ie http://colin.guthr.ie/ Day Job: Tribalogic Limited [http://www.tribalogic.net/] Open Source: Mageia Contributor [http://www.mageia.org/] PulseAudio Hacker [http://www.pulseaudio.org/] Trac Hacker [http://trac.edgewall.org/]