RE: [linux-audio-dev] re: [linux-audio-user] A bit of good news--paper now available for your viewing pleasure and/or comments
On Fri, 2004-05-28 at 10:55, Ivica Ico Bukvic wrote: > Hmm, so just for my own understanding of this, if let's say 2 soundcards A > and B lack sync between themselves, yet are being fed in appropriate > intervals small buffers of audio data from JACK, what is preventing them > from staying in sync? The slower card will have to be fed something other than the source material from time to time to be able to catch up to the faster one (the "source" is coming at only one speed from only one place and going to two different places that need to be fed at slightly different rates). The "something to be fed" will be probably silence, that is, a click :-) The size of the buffer and the amount of drift between cards will determine how often you get a click (if the software would support doing this at all, of course). -- Fernando
Re: [linux-audio-dev] re: [linux-audio-user] A bit of good news--paper now available for your viewing pleasure and/or comments
On Fri, May 28, 2004 at 01:37:46PM -0400, Ivica Ico Bukvic wrote: > Forgot to add that my assumption is (in addition to my previous statement) > if JACK was then running using reasonably small buffers the drift would be > then minimized if not alleviated since JACK is one that is dispatching the > buffers at appropriate time, right? But each card has its own internal hardware clock that determines the rate at which the DACs consume (and the ADCs produce) data. Software cannot change this. Unless the clocks are locked at the hardware level, one card will produce & consume data to/from jack's alsa IO layer faster than the other. Pretty soon you are screwed. If the cards *are* synced at the hardware level, it should work. This can be done either via word-clock connections if the cards support that, or by a quick hack: connect S/PDIF output on one card to S/PDIF input on the other. Set the second card to use its S/PDIF input as clock source. This hack assumes you have S/PDIF I/O and are willing to sacrifice it for synchronization. -- Paul Winkler http://www.slinkp.com
RE: [linux-audio-dev] re: [linux-audio-user] A bit of good news--paper now available for your viewing pleasure and/or comments
Hmm, so just for my own understanding of this, if let's say 2 soundcards A and B lack sync between themselves, yet are being fed in appropriate intervals small buffers of audio data from JACK, what is preventing them from staying in sync? For instance, the way I see it is that if one card even spits out the audio at a fraction faster than other, due to sample buffer size being small enough, such inconsistency imho should not be even noticed unless obviously there is something really screwed up and the speed of output is seriously off in which case such card is obviously deemed inadequate for any serious audio work anyhow. Plase correct my assumption if I am [most likely] wrong. Also a verbose explanation would be highly appreciated. Thanks! Ivica Ico Bukvic, composer & multimedia sculptor http://meowing.ccm.uc.edu/~ico/ > -Original Message- > From: [EMAIL PROTECTED] [mailto:linux-audio- > [EMAIL PROTECTED] On Behalf Of Jack O'Quin > Sent: Friday, May 28, 2004 1:46 PM > To: The Linux Audio Developers' Mailing List > Cc: 'A list for linux audio users' > Subject: Re: [linux-audio-dev] re: [linux-audio-user] A bit of good news-- > paper now available for your viewing pleasure and/or comments > > "Ivica Ico Bukvic" <[EMAIL PROTECTED]> writes: > > > Hasn't there been some success stories in the past regarding this? I > > might be obviously very wrong about this but I thought that if one > > designed a meta-device in the asoundrc making two soundcards one > > multichannel soundcard and then invoking JACK on top of it, that it > > should work? > > Many attempts have been reported. I don't recall any success stories, > but maybe there were some. Most people want to do this with two cheap > consumer "multimedia" cards. That won't work, because they can't be > synchronized. > -- > joq
Re: [linux-audio-dev] re: [linux-audio-user] A bit of good news--paper now available for your viewing pleasure and/or comments
"Ivica Ico Bukvic" <[EMAIL PROTECTED]> writes: > Forgot to add that my assumption is (in addition to my previous > statement) if JACK was then running using reasonably small buffers > the drift would be then minimized if not alleviated since JACK is > one that is dispatching the buffers at appropriate time, right? JACK expects there to be *no* drift and does *nothing* to manage this problem. It can only work with high-end cards using word-clock or other sample-accurate synchronization. Probably someone has succeeded with that (though I can't recall a specific report). -- joq
Re: [linux-audio-dev] re: [linux-audio-user] A bit of good news --paper now available for your viewing pleasure and/or comments
"Ivica Ico Bukvic" <[EMAIL PROTECTED]> writes: > Hasn't there been some success stories in the past regarding this? I > might be obviously very wrong about this but I thought that if one > designed a meta-device in the asoundrc making two soundcards one > multichannel soundcard and then invoking JACK on top of it, that it > should work? Many attempts have been reported. I don't recall any success stories, but maybe there were some. Most people want to do this with two cheap consumer "multimedia" cards. That won't work, because they can't be synchronized. -- joq
RE: [linux-audio-dev] re: [linux-audio-user] A bit of good news--paper now available for your viewing pleasure and/or comments
Forgot to add that my assumption is (in addition to my previous statement) if JACK was then running using reasonably small buffers the drift would be then minimized if not alleviated since JACK is one that is dispatching the buffers at appropriate time, right? Ivica Ico Bukvic, composer & multimedia sculptor http://meowing.ccm.uc.edu/~ico/ > -Original Message- > From: [EMAIL PROTECTED] [mailto:linux-audio- > [EMAIL PROTECTED] On Behalf Of Ivica Ico Bukvic > Sent: Friday, May 28, 2004 1:22 PM > To: 'A list for linux audio users'; 'The Linux Audio Developers' Mailing > List' > Subject: RE: [linux-audio-dev] re: [linux-audio-user] A bit of good news-- > paper now available for your viewing pleasure and/or comments > > Thanks Steve for your insight! > > Hasn't there been some success stories in the past regarding this? I might > be obviously very wrong about this but I thought that if one designed a > meta-device in the asoundrc making two soundcards one multichannel > soundcard > and then invoking JACK on top of it, that it should work? > > Please let me know so that I can make appropriate changes. > > Ivica Ico Bukvic, composer & multimedia sculptor > http://meowing.ccm.uc.edu/~ico/ > > > > -Original Message- > > From: [EMAIL PROTECTED] [mailto:linux-audio- > > [EMAIL PROTECTED] On Behalf Of Steve Harris > > Sent: Friday, May 28, 2004 12:43 PM > > To: 'A list for linux audio users'; 'The Linux Audio Developers' Mailing > > List' > > Subject: Re: [linux-audio-dev] re: [linux-audio-user] A bit of good news > - > > -paper now available for your viewing pleasure and/or comments > > > > I'm not really happy about the bit about JACK saying "as well as > > potentially multiple soundcards"... it seems unlikly to me that JACK > will > > ever support that directly (without wordclock-like sync, when any system > > should be able to do it). > > > > Thanks for the timemachine plug though :) > > > > - Steve
RE: [linux-audio-dev] re: [linux-audio-user] A bit of good news --paper now available for your viewing pleasure and/or comments
Thanks Steve for your insight! Hasn't there been some success stories in the past regarding this? I might be obviously very wrong about this but I thought that if one designed a meta-device in the asoundrc making two soundcards one multichannel soundcard and then invoking JACK on top of it, that it should work? Please let me know so that I can make appropriate changes. Ivica Ico Bukvic, composer & multimedia sculptor http://meowing.ccm.uc.edu/~ico/ > -Original Message- > From: [EMAIL PROTECTED] [mailto:linux-audio- > [EMAIL PROTECTED] On Behalf Of Steve Harris > Sent: Friday, May 28, 2004 12:43 PM > To: 'A list for linux audio users'; 'The Linux Audio Developers' Mailing > List' > Subject: Re: [linux-audio-dev] re: [linux-audio-user] A bit of good news - > -paper now available for your viewing pleasure and/or comments > > I'm not really happy about the bit about JACK saying "as well as > potentially multiple soundcards"... it seems unlikly to me that JACK will > ever support that directly (without wordclock-like sync, when any system > should be able to do it). > > Thanks for the timemachine plug though :) > > - Steve
Re: [linux-audio-dev] re: [linux-audio-user] A bit of good news -- paper now available for your viewing pleasure and/or comments
I'm not really happy about the bit about JACK saying "as well as potentially multiple soundcards"... it seems unlikly to me that JACK will ever support that directly (without wordclock-like sync, when any system should be able to do it). Thanks for the timemachine plug though :) - Steve
RE: [linux-audio-dev] re: [linux-audio-user] A bit of good news -- paper now available for your viewing pleasure and/or comments
Oops, apologies for that. I will fix that shortly! Thanks for pointing that out! Best wishes, Ivica Ico Bukvic, composer & multimedia sculptor http://meowing.ccm.uc.edu/~ico/ > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > Sent: Friday, May 28, 2004 10:13 AM > To: ''A list for linux audio users''; ''The Linux Audio Developers' > Mailing List''; ''Ivica Ico Bukvic'' > Subject: Re: [linux-audio-dev] re: [linux-audio-user] A bit of good news - > - paper now available for your viewing pleasure and/or comments > > Very nice. I like the fact that you didn't sugar-coat it. There can be > problems > but it's usually worth the effort. I was disappointed that you didn't > mention > JAMin - AFAIK the only serious audio mastering software for Linux ;-) > > Jan > > > On Fri, 28 May 2004 00:05 , 'Ivica Ico Bukvic' <[EMAIL PROTECTED]> sent: > > >Ok, so the rough version of the paper (following initial 10-hour > revisions > >that converted my brain into a gray mush) is now available in the PDF > format > >from my website. If you are interested in providing some feedback as to > how > >I can make the paper even better, please let me know asap as I only have > >another day or so before I need to turn-in the paper. > > > >Also please note that the paper will be available in the ICMC proceedings > as > >a short version that lacks chapters 7 and 9 due to space constraints. The > >full paper will be available online-only. > > > >The url to the PDF is as follows: > >http://meowing.ccm.uc.edu/~ico/temp_online.pdf > > > >Any comments and/or suggestions are welcome and appreciated (although I > >honestly cannot guarantee that all of them will make it into final > revision > >due to aforementioned deadline). > > > >Time to hit the sack... > >Best wishes, > > > >Ivica Ico Bukvic, composer & multimedia sculptor > >http://meowing.ccm.uc.edu/~ico/ > > > > > > > >
Re: [linux-audio-dev] re: [linux-audio-user] A bit of good news -- paper now available for your viewing pleasure and/or comments
Very nice. I like the fact that you didn't sugar-coat it. There can be problems but it's usually worth the effort. I was disappointed that you didn't mention JAMin - AFAIK the only serious audio mastering software for Linux ;-) Jan On Fri, 28 May 2004 00:05 , 'Ivica Ico Bukvic' <[EMAIL PROTECTED]> sent: >Ok, so the rough version of the paper (following initial 10-hour revisions >that converted my brain into a gray mush) is now available in the PDF format >from my website. If you are interested in providing some feedback as to how >I can make the paper even better, please let me know asap as I only have >another day or so before I need to turn-in the paper. > >Also please note that the paper will be available in the ICMC proceedings as >a short version that lacks chapters 7 and 9 due to space constraints. The >full paper will be available online-only. > >The url to the PDF is as follows: >http://meowing.ccm.uc.edu/~ico/temp_online.pdf > >Any comments and/or suggestions are welcome and appreciated (although I >honestly cannot guarantee that all of them will make it into final revision >due to aforementioned deadline). > >Time to hit the sack... >Best wishes, > >Ivica Ico Bukvic, composer & multimedia sculptor >http://meowing.ccm.uc.edu/~ico/ > > >
