Re: [xwax-devel] xwax and jack
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hills
From: Matthieu C. <mc...@fr...> - 2010-12-22 15:15:48
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Well.... I found the issue...... Which was that my input sound was too high.... so obvious. I was confused because it's working great with ALSA. So.... Why is there a difference between input levels in ALSA and Jack? (Is the sound amplified by jack?) Comment regarding xwax: xwax does a very good job by adapting the input level to its needs , so it is easy to get strong /circle/ in the timecode scope. As I got a strong circle for almost all input volume, it is difficult to know if I am close or far from the ideal input level. My amplifier (NAD PP 2i) doesn't have a gain button. So I am using jack-rack to reduce the input level for xwax. (no option to reduce input in my mixer(audiophile 24/96)). Is there a better way? Xwax works great now. I am verrrry happy. Thank you for a nice software. Le 18/12/2010 01:31, Matthieu Caron a écrit : > I borrowed a sound card (audigy se) and xwax and jack are working fine. > The problem should be with my audiophile 24/96... > Is someone using this card (or has a tip)? > Thanks > > > On 12/17/2010 12:43 AM, Matthieu Caron wrote: >> On 12/16/2010 11:36 PM, Mark Hills wrote: >>> On Thu, 16 Dec 2010, Matthieu Caron wrote: >>> >>>> On 12/16/2010 08:18 PM, Mark Hills wrote: >>>>> On Thu, 16 Dec 2010, Matthieu Caron wrote: >>>>> >>>>>> Sorry to bother you again... >>>>> No worries! That's what the mailing list is for. >>>>> >>>>>> I have found out that xwax with Alsa is running with RTPRIO = 80. >>>>>> ($ ps -LO rtprio /proc_num/) >>>>>> >>>>>> With Jack, xwax is always running with RTPRIO = 15, whatever the settings >>>>>> I >>>>>> write in /etc/security/limits.d . >>>>> This sounds correct. When JACK is used, it handles the high-priority audio >>>>> thread on behalf of xwax. So if you are only using JACK, xwax's realtime >>>>> thread (priority 80) doesn't even start. >>>> Hi Mark, hi all, >>>> If I set Jack priority (from qjackctl's setup panel) to the maximum value >>>> (89), xwax's realtime thread gets a priority (RTPRIO) of 84. So it looks like >>>> xwax's realtime thread does actually start when using Jack on my computer (but >>>> you wrote it shouldn't?) >>> I'm not familiar with the implementation details of JACK, but it sounds >>> like this thread is a part of JACK's operation, not one of xwax's own. So >>> it would make sense that it is calling process_callback() from jack.c. >>> >>> You can confirm if xwax is starting its own thread. If it is, it will >>> print: >>> >>> Launching realtime thread to handle devices... >>> >>> to the console. >>> >> xwax is not starting its own thread. "Launching realtime thread to >> handle devices... " is not printed. >>>> Having the priority to 84 doesn't make a difference. >>>> >>>>> [...] >>>>>> Where does this value 15 come from? >>>>> Not sure. Are the rest of the apps in the system at 15? >>>> Seems that it was a pro-rata of the default priority of jackd (20). >>>> So: >>>> Jackd priority = 20 => xwax priority = 15 >>>> Jackd priority = 89 => xwax priority = 84 >>>> >>>>> I'm watching this thread, but haven't had any good suggestions to offer so >>>>> far. How did you make the recordings before? Perhaps you could take a >>>>> recording from within JACK; eg. route the audio straight through to >>>>> Ardour to determine whether the problem is with xwax feeding audio into >>>>> JACK, or with JACK feeding audio to the soundcard. >>>>> >>>> Regarding the previous recording (export_jack.ogg): >>>> xwax's output was directly routed to Ardour. So the problem seems to be with >>>> xwax feeding audio into JACK. >>> It's not a bug I've seen before, but it sounds almost like you have the >>> same buffers of audio being repeated. The most likely bug surrounds the >>> processing in process_deck() of jack.c. >>> >>> I'm not aware of any bugs in the xwax JACK output, so it would be good to >>> get to the bottom of this. >>> >>> Can you modify the value of MAX_BLOCK in jack.c and see if this changes >>> the sound you hear? Perhaps use some music to test, rather than >>> scratching. >>> >> I modified the value of MAX_BLOCK (with values from 1 up to 100000) and >> this doesn't change the sound I hear. >> >> >> >> ------------------------------------------------------------------------------ >> Lotusphere 2011 >> Register now for Lotusphere 2011 and learn how >> to connect the dots, take your collaborative environment >> to the next level, and enter the era of Social Business. >> http://p.sf.net/sfu/lotusphere-d2d >> > > ------------------------------------------------------------------------------ > Lotusphere 2011 > Register now for Lotusphere 2011 and learn how > to connect the dots, take your collaborative environment > to the next level, and enter the era of Social Business. > http://p.sf.net/sfu/lotusphere-d2d > |