From mboxrd@z Thu Jan 1 00:00:00 1970 From: Felix Homann Subject: Re: Need expert's advice - Fast Track Ultra (8R) dropping samples Date: Fri, 01 Oct 2010 13:00:05 +0200 Message-ID: <4CA5BF35.2030108@showlabor.de> References: <4C9DC7A1.8050001@showlabor.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from vwp5738.webpack.hosteurope.de (vwp5738.webpack.hosteurope.de [83.169.30.203]) by alsa0.perex.cz (Postfix) with ESMTP id AA08D2440B for ; Fri, 1 Oct 2010 13:00:05 +0200 (CEST) In-Reply-To: <4C9DC7A1.8050001@showlabor.de> 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: alsa-devel@alsa-project.org Cc: tiwai@suse.de, Clemens Ladisch List-Id: alsa-devel@alsa-project.org I guess the right place to fix the issues mentioned in my original post is in snd_usb_init_substream() in urb.c: case USB_ID(0x0763, 0x2081): /* M-Audio Fast Track Ultra 8R */ subs->ops.prepare_sync = prepare_playback_sync_urb; subs->ops.retire_sync = retire_playback_sync_urb; I've tried combinations using the _hs and _emu versions of the retire.../prepare... functions. It either didn't change anything or made it worse. I guess we need _ftu versions. Could somebody at least tell me how to find out what's exactly going wrong with the sync. Can I find something useful monitoring the urbs in Windows? Please, help me. We're so very close to full support of these devices, but I don't know how to proceed. Thanks in advance, Felix Am 25.09.2010 11:57, schrieb Felix Homann: > Hi, > > in that past months I've been trying get the Fast Track Ultra devices > working properly in Alsa. We've had lots of progress, most of the code > has moved to Alsa git and today I've even posted a patch for getting > mixer support for these devices. > > Now, I need to get some expert's advice: The devices seem to drop > samples or frames. Here's a report I've got today on the M-Audio forum: > > "I've got a subtle problem to report: I think audio playback is dropping > sample frames. To hear the problem, open Audacity at 48 kHz and play > a 10-kHz. sine wave. When I do that I hear a regular clicking sound, about > four clicks a second. I've tried recording the output and if I'm seeing > correctly, > exactly one sample frame in every 13312 (13x1024) is being dropped on > output. > I don't see anything similar on input. When either jack or Pd has both > the input and > the output open, the delay from input to output gradually decreases > until it forces > occasional sync errors. (I haven't tried this with audacity though.)" > > (see > http://forums.m-audio.com/showthread.php?714-Not-a-problem.-FastTrack-on-linux&p=98101#post98101) > > I could reproduce it on my machines, even at 44.1 kHz. The clicking > sound is very subtle, it goes unnoticed when not listening to pure sines > without attention to clicks. > > How can this be sorted out. Any ideas? > > > Kind regards, > > Felix > _______________________________________________ > Alsa-devel mailing list > Alsa-devel@alsa-project.org > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel > >