Hi all,
I've had an interesting discussion with a professor and a distinguished
member of the electroacoustic music community regarding audio latencies
which made me realize that I did not understand the issue in its
entirety. Hence, I looked around the net in order to educate myself.
I soon stumbled across the following site:
http://old.lwn.net/1999/0916/a/latency.html
Admittedly, it's quite old but that, if anything speaks only in Linux's
favor in terms of its pro-audio readiness. At any rate, I was checking
out the benchmark data and was wondering as to how did this
person/software app get to the 0.73ms buffer fragment that is equal to
128bytes? In other words, what sampling rate was used?
128 bytes in 44100Hz sampling rate = 3ms
128 bytes in 88200Hz sampling rate = 1.45ms
128 bytes in 176400Hz sampling rate = 0.725ms (this one being obviously
closest, but at the same time, what kind of hardware supports this
sampling rate, especially in 1999 when this test was done?)
128 bytes in 192000Hz sampling rate = 0.3ms
So what gives? It seems like it is some kind of a 176k-ish sampling rate
that, AFAIK does not exist.
Furthermore, my question is what app was used to produce those
graphs/results and whether these latency tests take into account
hardware latencies (i.e. DSP converters, PCI->CPU->PCI->output etc.), in
other words, is this latency that is achievable with the following
setup:
Input->soundcard->cpu(with some kind of DSP)->soundcard->Output
Your help on this matter is greatly appreciated!
Ivica Ico Bukvic, composer & multimedia sculptor
http://meowing.ccm.uc.edu/~ico
-------- directBOX Reply ---------------
From: clemens(a)ladisch.de
To : linux-audio-user(a)music.columbia.edu
Date: 06.10.2003 15:52:02
hexe_2003(a)directbox.com wrote:
> ESS-Solo1
MIDI on the ES1938 doesn't work (because ESS' documentation isn't).
Get another sound card.
Regards,
Clemens
-----
REALLY ?!??!?!?! Well, that also sounds possible :(((((((((((((
baaad :) ; Well, if its true ( I'll check that :) ): THX A LOT !!!!
( I thought something like ' I bought a 89 EUR MIDI-keyboard and it doesn't work '
greez, Sascha Retzki
---------
Well, I want to add this question :
Does a ES1371 work ? ( it is the name Knoppix tells me, that is 'hwdetect' and this
should be the OSS-Layer ...)
greez, Sascha Retzki
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two years ago i did a bunch of testing on latency to find the best kernel
and patches for my system, and got some damn good results with several
kernels (the best being 2.4.12-ac3-pe (alan cox's patch and pre-emptive
kernel patch using alsa on suse 7.3 with gcc 2.96 20000731). i now have a
new computer with gentoo linux and alsa 0.9.6, and can only get 16 ms
latency with perfect results. same soundcard - m-audio audiophile 2496
(ice1712). i've used kernel 2.4.20 with pe, ll, and some other options,
compiling with gcc version 3.2.3 20030422, and i get the same result with
all of them (as well as without pe or ll).
does anyone know what the problem could be? alsa version? gcc version?
kernel version? hardware (eth0 and soundcard share irq - never thought to
test without eth0 loaded)? i'd like to get latency under 4 ms.
thanks for your input,
dave
hello - I think this is a simple question - right now when I record into
ardour, there's dang near a half second delay before it actually spits it
back out - that delay is reflected in the recording, too - I didn't THINK
this was happening yesterday...
is this a latency thing? I know I haven't maximized my latency, I'm running
the redhat kernel from planet ccrma, not the actual planet ccrma kernel and
when I check to see if low latency is turned on, I find that I don't even
have a low latency patch :)
the weird thing is I SWEAR is wasn't happening yesterday :)
--
--------------
Aaron Trumm
NQuit
www.nquit.com
--------------
-------- directBOX Reply ---------------
From: clemens(a)ladisch.de
To : linux-audio-user(a)music.columbia.edu
Date: 06.10.2003 15:52:02
hexe_2003(a)directbox.com wrote:
> ESS-Solo1
MIDI on the ES1938 doesn't work (because ESS' documentation isn't).
Get another sound card.
Regards,
Clemens
-----
REALLY ?!??!?!?! Well, that also sounds possible :(((((((((((((
baaad :) ; Well, if its true ( I'll check that :) ): THX A LOT !!!!
( I thought something like ' I bought a 89 EUR MIDI-keyboard and it doesn't work '
greez, Sascha Retzki
__________________________________________________
Verpassen Sie keine eBay-Auktion und bieten Sie bequem
und schnell über das Telefon mit http://www.telefonbieten.de
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-------- directBOX Reply ---------------
From: holborn(a)telefonica.net
To : linux-audio-user(a)music.columbia.edu
Date: 04.10.2003 15:16:56
On Sábado, 4 de Octubre de 2003 13:56, hexe_2003(a)directbox.com wrote:
> Hello!
>
> I bought a Midi-Keyboard yesterday and now I'd like to connect it to my
> Soundcard. ( ESS-Solo1 , alsa-driven (configured correctly))
> Well, Am I right that I use aconnect to connect my External Midi-Port
> (which should be the midi-in port, right?) to my internal FM synth to make
> music with rosegarden4 and adour and so on ?
>
Keyboard "OUT" to Computer "IN" is the way ... then use aconnect.
Josep
----------------
Well, I thought exactly the same. Maybe I'll try another way ... Do you know
possibilities to connect a MIDI-keyboard to applications via the OSS-layer ?
Or can I make something wrong with alsa, too ?
I used 'aconnect 64 65' , where 64 is my External MIDI port and 65 is
the internal FM synthesizer... .
__________________________________________________
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Hello!
I bought a Midi-Keyboard yesterday and now I'd like to connect it to my Soundcard.
( ESS-Solo1 , alsa-driven (configured correctly))
Well, Am I right that I use aconnect to connect my External Midi-Port (which should be
the midi-in port, right?) to my internal FM synth to make music with rosegarden4 and
adour and so on ?
greez Sascha Retzki
__________________________________________________
Verpassen Sie keine eBay-Auktion und bieten Sie bequem
und schnell über das Telefon mit http://www.telefonbieten.de
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-------- directBOX Reply ---------------
From: guy.clotilde(a)wanadoo.fr
To : linux-audio-user(a)music.columbia.edu
Date: 06.10.2003 14:38:27
On Sun, 05 Oct 2003 16:01:21 +0200, hexe_2003(a)directbox.com wrote / a écrit:
> Hello again,
>
> Iam the guy with the Midi-keyboard!! I've heared that some MIDI-keyboards don't
> send a note-off event, so they just send another note-on event.
I never heard of|used such keyboard.
----------
Well, I also contacted the maintainer of the keyboard, and as it looks like on this list and in the
mail of the maintainer, it just could be a driver problem :) ...
That is REALLY good ( software is free, we all know :)) ), but .. what is wrong ?
Maybe I try the OSS-drivers, but I don't know howto set-up the OSS-drivers with midi ...
Could you give me some advices ??
greez, Sascha Retzki
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Hello again,
Iam the guy with the Midi-keyboard!! I've heared that some MIDI-keyboards don't
send a note-off event, so they just send another note-on event. I don't know if mine
is such a stupid midi-keyboard, so maybe some guys at lau know it:
Evolution MK 149
greez, Sacha Retzki
__________________________________________________
Verpassen Sie keine eBay-Auktion und bieten Sie bequem
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