Hi,
I'm reading through the Alsa HOWTO and wondering if there are any buffer
setting or other options for setting internal buffer sizes in Alsa? I
normally set these things myself in jack, but in this case cannot.
One individual that I'm working with is getting excessive xruns on a
laptop. His BIOS does not seem to allow IRQs be set for any internal device.
His sound chip is on IRQ5, which is about as bad as it's going to get.
He is attempting to play a DVD to his screen and sound device, but is
getting excessive xruns. We're just searching around for ideas on how to
approach the problem.
If there are no module load options, might this be approached by setting
some buffer size in alsa itself and recompiling?
Anyway, thanks!
Mark
Hi everyone,
Just released the latest revision of the IETF Internet-Draft
to standardize the RTP packetization for MIDI. The document reflects
the comments submitted on the last document revision by several
LAD-folks (see the document change log for details ...).
While this draft isn't the "Last Call" document, we're
probably only a few revisions away from Last Call, so if anyone has
been holding off on the reviewing the memo and sending comments, now
is a good time to do so ... below is the abstract and document
download info:
---
>From: Internet-Drafts(a)ietf.org
Subject: I-D ACTION:draft-ietf-avt-mwpp-midi-rtp-05.txt
Date: Tue, 24 Sep 2002 07:52:50 -0400
A New Internet-Draft is available from the on-line Internet-Drafts
directories. This draft is a work item of the Audio/Video Transport
Working Group of the IETF.
Title : The MIDI Wire Protocol Packetization (MWPP)
Author(s) : J. Lazzaro, J. Wawrzynek
Filename : draft-ietf-avt-mwpp-midi-rtp-05.txt
Pages : 94
Date : 2002-9-23
The MIDI Wire Protocol Packetization (MWPP) is a general-purpose
RTP packetization for the MIDI command language. MWPP is suitable
for use in both interactive applications (such as the remote
operation of musical instruments) and content-delivery applications
(such as MIDI file streaming). MWPP is suitable for use over
unicast and multicast UDP, and defines tools that support the
graceful recovery from packet loss. MWPP may also be used over
reliable transport such as TCP. The SDP parameters defined for MWPP
support the customization of stream behavior (including the MIDI
rendering method) during session setup. MWPP is compatible with the
MPEG-4 generic RTP payload format, to support the MPEG 4 Audio
object types for General MIDI, DLS2, and Structured Audio.
A URL for this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-ietf-avt-mwpp-midi-rtp-05.txt
---
-------------------------------------------------------------------------
John Lazzaro -- Research Specialist -- CS Division -- EECS -- UC Berkeley
lazzaro [at] cs [dot] berkeley [dot] edu www.cs.berkeley.edu/~lazzaro
-------------------------------------------------------------------------
> david(a)gardena.net writes:
> you can't ask units about things,
> unless you have two cables - and that's not really part of the
> standard
Actually, it is. The System-Exclusive Universal ID command
space is general-purpose functionality that, in many cases,
assumes units talking to each other via cable pairs. See:
http://crystal.apana.org.au/~ghansper/midi_introduction/midi_sysex_universa…
for details. The simplest example is the Generic Handshaking
instructions, which do flow-control for big Sample Dumps via
a set of commands implementing ACK, NAK, WAIT, EOF, etc.
-------------------------------------------------------------------------
John Lazzaro -- Research Specialist -- CS Division -- EECS -- UC Berkeley
lazzaro [at] cs [dot] berkeley [dot] edu www.cs.berkeley.edu/~lazzaro
-------------------------------------------------------------------------
So who is orm, and are they available for comment?
So I think I have things narrowed down a little. It seems that he
cardbus/Digiface combo is stuck at a sample rate of 32k, even though the
/proc file states that it is at 48k. This dose not happen using the pci
interface.
The Control, Status, and Status2 registers seem correct. So I am lost on
where to go next. Any suggestions?
On Fri, 2002-07-05 at 17:03, Paul Davis wrote:
> >Just unwrapped my new thinkpad, so I am thinking of ordering the cardbus
> >interface for my hdsp. Has anyone gotten the cardbus to work with the
> >digiface box?
>
> it works (orm has reported it working). it seems very dependent on the
> kernel, cardbus utilities and possibly the underlying hardware. if
> these 2 succeed with their task of making the pcmcia card appear like
> a normal PCI device, then everything proceeds as normal. several
> people have combinations of these 3 that fail at this goal.
--
drh(a)niptron.com
Great spirits have always encountered violent opposition from mediocre
minds.
-- Albert Einstein
They laughed at Einstein. They laughed at the Wright Brothers. But
they
also laughed at Bozo the Clown.
-- Carl Sagan
Hi,
I haven't looked at the latest versions of Fruity for a while but started
working on something that is quite similiar to your description in the
beginning of this year. I have now reached a certain level where the core
signaling engine becomes usable.
I don't know if you have ever worked with buzz but I consider some sort of UI
quite similiar to its.
How does this sound to you?
mm
On Wednesday 04 September 2002 8:08 am, Tim Hockin wrote:
> I know someone on here once posted about doing a FruityLoops work-alike
> app. Are you still around?
>
> I have been tossing about this idea for a free, high quality,
> well-architected, virtual studio for a while. If I had a collaborator or
> two, I'd probably be more inclined to do it.
>
> Anyone? My thoughts so far:
> * a plugin API like LADSPA but less 'S'
> * a modular-synth core engine
> * layered control - modular synth, or a Fruity-like interface on top
> * written in C
> * clean code, modular, extensible, blah blah...
>
> There is a ton of code waiting to be borrowed. Whole portions may not need
> to be written. I haven't investigated THAT far yet.
>
> Tim
We are using LynxOne soundcard with OSS driver in digital mode with external clock option.
We want to check the presense of Digital clock, before starting the audio process.
Initially, we thought of using the input H/W buffer sample count to check that. But it does not work always. Sometime even with valid external clock, driver won't place any data in the hardware buffer even after few minutes.
Did you come across this problem?
Also we have to delay the Timecode. We are not using MIDI feature. But time code comes only in MIDI port. Is it easy to change the timecode (LTC) in the MIDI stream?
-----Original Message-----
From: Paul Davis [mailto:pbd@op.net]
Sent: Thursday, September 19, 2002 7:16 AM
To: linux-audio-dev(a)music.columbia.edu
Subject: Re: [linux-audio-dev] Basic information
>>> Hi. Could anyone point me to some very basic information to give me
>>> some
>>> idea of programming for sound in linux.
>>
>> we can't even begin to answer such a nebulous question i'm afraid.
>
>why not? I would just start to have a look at other sound applications
>and
>try to understand what they do. That's actually how I did it. And then
>you
>can get yourself a working installation of alsa and try to build the
>existing documentation. In the meantime there's even a small primer,
>how to open a sound device and make some noise.
because its far from clear that this is the right thing to do with an
SC port. if you don't know what SC is, you might not realize that the
way 95% of all linux audio applications are written doesn't fit with
SC's basic architectural model at all. many people think that writing
a soundapp consists of opening a device, dumping some data to it and
closing it. some programs can do that, but SC cannot.
i don't know how much the questioner knows about the internal design
of SC. its therefore not possible to answer the question until he pins
down what he wants to do.
--p
_______________________________________________
linux-audio-dev mailing list
linux-audio-dev(a)music.columbia.edu
http://music.columbia.edu/mailman/listinfo/linux-audio-dev
Hi. Thanks to everyone for the advice. I've been poking around
in a number of sources (including the Supercollider code), and
it appears that I need to spend a bit more time on various
learning curves. My immediate aim is to install WindowMaker
and GNUStep on my linux box (tried to do so on a solaris box
but encountered 'difficulties' :-(), and write a few simple gui
applications in objective-c. After that, I can have another
look at the task at hand. SC does use core-audio, and I've
noted the advice to use JACK.
Hopefully I'll resurface on this problem in a while!
Cheers,
Ross-c
Hi there,
Do you (or the list) happen to know if anyone has considered making TiMidity++
a LADSPA host?
I was thinking it might be fun to have a midi sequencer with a rather large
library of MIDI controllers. I was thinking of using Non-Registered
Parameters - one to select the LADSPA plug in (by number), one to set its
position in the plugin chain, and as many more as is required to control it -
unless someone fancies getting the LADSPA plugins allocated numbers by the
MIDI Manufacturers Association...
I did an archive search on "timidity" and found nothing -- is software
sequencing off topic or is there somewhere else I should go to discuss
changes to TiMidity++?
Thanks,
-- Peter
Hi. Thanks of the responses (I only just got the linux-audio-dev digest).
As some people have noticed, my queries are at an early stage. No, I don't
yet know too much about the way that the SC code works.
(i) Yes, the gui is going to be the major problem. However, while I have
only used the demo version, and not the latest version, I don't remember
*that* much complexity in the gui. The graphic version may be more
tricky.
(ii) What I meant by a source code to source code cross-compiler is this:
I don't want to be in the situation where I port one version of SC (providing
that this ever happens, I'm still asking questions on the SC-dev list to
find out the status of any linux port), and then have to do the same work
for a later port. What I wanted to do is the following: Find the Mac-specific
OS calls in the SC code, and understand what they do (sound, gui, and other).
Then, write an extra module of code declaring the same functions, with
linux specific code to achieve the same effect. Yes, I know this is likely
to be complex, and may require the creation of a fairly large number of
objects. Then, for things that cannot be so easily fixed, like OS and/or
gui toolkit #includes, write a program that will modify the source code into
a form so that any more missing bits can be fixed. If I can do this, then
hopefully the effort in porting future mac OS releases would be much easier.
I.e. unlike a traditional source code to source code cross-compiler that
would compile (e.g.) fortran to C, I'll be compiling max-os specific c/c++ into
linux c/c++, hopefully eased by the creation of a set of libraries of
'faked' mac os x calls.
(iii) Basic linux audio code samples will be of use, as I need to understand
both systems to do the patching described in (ii). So, I'll look some up.
And, (iv), though I should have mentioned this more explicitly in my first
email, I'm also interested to know if someone's doing this already.
Cheers,
Ross-c
