Linux-audio-dev

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7513 discussions

Re: [linux-audio-dev] [ot] [rant] gcc, you let me down one time too many

by eviltwin69＠cableone.net

On Tue, 7 Jun 2005 10:18 , Paul Winkler <pw_lists(a)slinkp.com> sent: >On Mon, Jun 06, 2005 at 04:12:27PM -0500, Jan Depner wrote: >> I just have to respond to this. I have been writing code for 27 >> years and every time I get a neophyte programmer in they want to cut >> corners to save programming time. Here's the bottom line - if it saves >> you a day in coding but costs the user 3/4 of a second in application >> time would you consider that a good tradeoff? Not if you have over 100 >> users and they're having to deal with that 3/4 of a second 20 or so >> times a day, every day for a year. Remember, it's only hard for you to >> program it correctly once - it's a PITA for the user many times a day. > >I sort of agree, with the very large caveat that "once" is unlikely. >The time to write the code is often dwarfed by the time to maintain >the code. So your optimizations had damn well better be as readable >as you can make them, and well-commented. > Too true. That's why I comment like a madman ;-) Jan

20 years, 3 months

[linux-audio-dev] Re: Software controller for homemade edrums

by Juhana Sadeharju

>From: Olivier Guilyardi <ml(a)xung.org> > >http://www.samalyse.com/labs/edrum Because I don't want build anything, I would record drumming on whatever I find from our kitchen. The software should detect the pitch and volume of the hits. If only one microphone is used, choosing differently pitched objects for the controller makes it easier to separate the objects. Juhana -- http://music.columbia.edu/mailman/listinfo/linux-graphics-dev for developers of open source graphics software

20 years, 3 months

[linux-audio-dev] disaster day #1

by Dave Phillips

Greetings: I've been having some problems with my desktop machine during and after booting into Planet CCRMA RH9. At first I started getting some kernel panics booting into the system, then I started having trouble during operation of the system. X would suddenly freeze shortly after I started it, usually after the first mouse move. Okay, so I don't panic because I have another drive in the same box running FC3, so I figure I'll just boot into that system instead and transfer files before everything heads south. At first everything seemed fine on that drive, but soon after I started using it FC3 started showing the same symptoms with sudden reboots and total freezes of the machine. I've been able to transfer a lot of stuff to my laptop via the local network, but mounting the RH9 drive is very dangerous, things can freeze at any moment. Alas, there's still stuff on that drive that I'd like to retrieve. So there's something wrong with the box. Can anyone point me in the right direction to begin troubleshooting this machine ? Could it be RAM ? The graphics card ? Or what ?? And how can I test things on the hardware side, i.e., what utilities are indicated ? Any and all suggestions vastly appreciated. Best, dp

20 years, 3 months

[linux-audio-dev] Speech analysis

by Susan Cragin

Hi. I'm a lurker from the Open-Source Speech Recognition Initiative. We are starting to collect voice samples and need an audio program that can segment speech by word, or attempt to, by recognizinig all the silences and placing markers at each location. Any ideas? Thanks for any and all input. Susan R Cragin, Clerk OSSRI Open Source Speech Recognition Initiative http://www.ossri.org http://harvee.org/mailman/listinfo/ossri A Massachusetts Not-For-Profit Organization

20 years, 3 months

Re: [linux-audio-dev] Please test the RT rlimits patch for audio

by Jonathan Woithe

On Wed, Apr 27, 2005 at 08:13:21AM +1000, Luke Yelavich wrote: > Some distros, like Slackware do not use pam. How could this patch still > be used? I've written a small setuid utility which gives access to the new resource limits on an otherwise unpatched system (so long as a kernel with the new resource limits is running, of course). It should work regardless of whether PAM is installed, but my main motivation in writing it was to allow me to access the new functionality under Slackware 10.x (with a 2.6 kernel). Grab the tarball from http://www.physics.adelaide.edu.au/~jwoithe/set_rtlimits-1.0.0.tgz Sorry, no homepage yet. Read the enclosed README and manpage for full details. In short, a simple text file /etc/set_rtlimits.conf is used to configure which users (or groups) can run which programs with elevated realtime/nice priorities. The maximum priorities requestable is limited on a user+program basis, so a single user or group can have different maximum priorities for different programs if this is desired. Once set up, using it is as simple as inserting set_rtlimits in front of the program you wish to run (and its parameters). For example: set_rtlimits -r=100 /usr/local/bin/muse -a will run muse with the dummyaudio driver with a maximum realtime priority resource limit of 100. Note the full path to the program to execute is required so ordinary users can't just substitute their own binaries of the same name as "allowed" programs. It might not be the most secure program written (although I've tried to avoid gaping holes), but it gets the job done for me. Regards jonathan

20 years, 3 months

[linux-audio-dev] ANN: set_rtlimits for PAM-less systems and perhaps others

by Jonathan Woithe

With the recent adoption of the realtime rlimits patch into the mainline kernel, people have needed a way of utilising this for their music software. There is apparently a PAM module out there which can be used if one's system uses PAM, but for people on Slackware (which doesn't use PAM) - and perhaps other distributions as well - this is not an available option. set_rtlimits is a small program I hacked up over the weekend to allow controlled non-priviledged access to realtime scheduling through the new RTPRIO resource limit. set_rtlimits needs to be setuid root but it only runs at elevated priviledges when setting the resource limits. Furthermore, the users who are permitted to use set_rtlimits are controlled through a hardcoded central configuration file (/etc/set_rtlimits.conf), as are the programs those users can run via set_rtlimits and the maximum realtime and nice priorities the users can request for each program. Programs must be specified using absolute paths, so a malicious user can't just run their own ardour binary, for example. There is no homepage for this yet; simply grab the source from http://www.physics.adelaide.edu.au/~jwoithe/set_rtlimits-1.0.0.tgz Documentation is by way of the included README and manpage. Note that this is not polished software. It's not autoconf-ised, although hopefully it won't require too much tweaking to compile on a variety of systems. It probably isn't written in a very portable way, and although it poses no security issues to the best of my knowledge (beyond the usual issues with setuid root programs and realtime priorities) it has not been extensively audited. Having said that it gets the job done for me and might be useful for others. My time is limited at present which is why the rough edges remain. Development was done under Slackware 10.0 running kernel 2.6.12-rc5. Using this program I have successfully run Ardour 0.9beta29 and muse 0.7.2pre1 with Jack 0.99.73 under 2.6.12-rc5 for short periods. Bug reports, improvements, suggestions and patches are welcome; send to the email address included in the tarball documentation. Regards jonathan

20 years, 3 months

[linux-audio-dev] OT: Survey facing design patterns and communication

by Nico

Hello everybody! We are a group of students at "Freie Universitaet Berlin". As part of our computer science studies we are going to do a survey facing the use of design patterns in communication. Examples of design patterns are "Abstract Factory", "Singleton", "Composite", "Iterator" and "Listener". If you know what we are talking about, you are welcome to take part in our survey. It takes about 5 minutes to fill out the form. Just jump to: http://study.beatdepot.de If you agree, we will send you the results of our survey. Thanks in advance for your participation! And sorry for the interruption of your discussion.

20 years, 3 months

[linux-audio-dev] Algorithm for displaying waveforms

by Them

For a small application I am developing, I need to display waveforms (read-only) from audio data loaded into my application using libsndfile. My question is about displaying a waveform in a GUI window -- I have searched around the net looking for general algorithms but haven't seen anything that describes this. I haven't tried coding this yet, so I am asking if someone can describe the basic algorithm or point me in the right direction to a book, web site, the source file in Ardour or whatever. Even just a high-level description of the basic algorithm would be good -- I am thinking somewhere along the lines that I am taking the values of samples and drawing line segments from point to point. Thanks in advance! -- Brett

20 years, 3 months

[linux-audio-dev] 30db loudness difference at these cases

by Andrew Gaydenko

Hi, All! I'm rather frustrated with my situation, so I'm not sure which mailing list is the most appropriate for my question. I have Terratec Aureon 7.1 Space card which is used with ICE1724 alsa driver (1.0.8, 1.0.9a). An appropriate .asoundrc fragment is shown below. All works fine except for at some cases a sound level is about 30db lower rather at another cases. Of course, alsamixer settings are the same. --- "Normal" cases are: --- 1. Playing back with aqualung this way: aqualung -o alsa -d default 2. Using any JACK-enabled app (ReZound, aqualung) --- "-30db" cases are: --- 1. aplay -d default <file> 2. xine engine with any frontend (amaroK, Kaffeine) Will anybody be so kind to suggest steps to find this difference reason? Andrew ////////////////// .asoundrc fragment //////////////////////////// pcm.!default { type plug slave { pcm "2x4" format S32_LE } } pcm.2x4 { type route slave.pcm surround71 slave.channels 8 ttable.0.0 0.05 ttable.1.1 0.05 ttable.0.2 1 ttable.1.3 1 ttable.0.4 1 ttable.1.5 1 ttable.0.6 1 ttable.1.7 1 }

20 years, 3 months

[linux-audio-dev] Objective-C (was: gcc, you let me down...)

by Toby

Tim Goetze wrote: > I'm pretty much sold on Python as my high-level language of choice and > very reluctant to diversify in computer language literacy any further. I feel your pain. Python is by far my favorite language ever. However, I've recently been looking for an alternative *compiled* object-oriented language, because let's face it, Python is on average 10 times slower than C. Sometimes you just can't afford it. Enter Objective-C: - STRICT SUPERSET OF C: every valid C program is a valid ObjC program. This makes it trivial to include or link to C code and libraries and to mix procedural, object-oriented and ASM code in the same *file*. - SIMPLE: ObjC is plain C with one syntax addition and a few new keywords. It only extends the C language to support Smalltalk-like object-oriented features, because that's all you're going to need. No more operator overloading, templates, references, 'const', etc. - DYNAMICALLY TYPED: messages (method calls) are delivered according to the dynamic type of the target object, not to some static type. This is how Python works. You can even send an object a message that is not specified in its interface. This might seem like a bad idea, but instead it allows for powerful delegation-based design patterns. - FAST: Objective-C performs dynamically bound message calls very quickly, about 1.5-2.0 times as long as a plain C function call! Objective-C is the language of choice for MacOS X development. GCC compiles it very well too. Using GNUstep (optional) as the system and GUI framework, you can make a GUI program that compiles almost without changes on both GNU/Linux and MacOS X! (Windows port in the working.) > > Well I really like to separate C and C++. C is unashamedly a low > > level language. C++ OTOH tries to be both low level and high level. > > In comparison to C, C++ is a poor low level language. Compared to > > Python or Ocaml, C++ is a poor high level language. Objective-C can be as low-level as C (including #define, ASM...) and as high-level as Python (albeit a bit more verbose) IN THE SAME FUNCTION! Toby -- One theory states that if anyone ever learns how to use all of Emacs, it will instantly disappear and be replaced by something even more bizarre and inexplicable. Another theory states that that's how VI was invented.

20 years, 3 months

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Linux-audio-dev