Linux-audio-dev

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7534 discussions

Re: [linux-audio-dev] swh plugins and fixing undenormalize

by eviltwin69＠cableone.net

I have a denormal fix without a branch but you probably don't want to see it ;-) It's pretty simple, just OR the bits of the exponent together which gives either 0 (denormal) or 1, typecast that to float, and then multiply the original float by that (0.0 or 1.0). Voila, no branch, but it is messy looking ;-) Jan On Thu, 24 Jun 2004 11:03 , Tim Blechmann <TimBlechmann(a)gmx.net> sent: >> Since the problem is denormalised numbers, has anybody thought of >> adding a small DC offset (1e-15) or alternating the >> addition/subraction of a small value? >of course it is possible to add a small dc offset ... but what if we are >working in a feedback loop? or even worse with a high pass filter? >if you alter addition/substraction and send it throuth a low pass filer? >the denormal problem is not a trivial one, but afaik a macro like this >is the only one working for sure... > >cheers .... tim > >-- >TimBlechmann(a)gmx.de','','','')">TimBlechmann(a)gmx.de ICQ: 96771783 > >After one look at this planet any visitor from outer space >would say "I want to see the manager."

21 years, 7 months

[linux-audio-dev] fixed point?

by derek holzer

hi all, I'm starting some work with audio applications on Familiar for the IPAQ. I was wondering if anybody here can point me in the direction of some fixed-point audio software for "investigative" purposes. Probably the holy grail of fixed-point audio would be a fixed-point MP3 or OGG encoder. I've been pouring through list archives and Google, trying to turn one up, but all I find are embedded, proprietary encoders. I know about MAD and Tremor [for mp3 and ogg repsectively], but both are decoders only. Anybody working on a fixed-point version of Ecasound, BTW? I've seen it already runs on the IPAQ, just very slowly... What about other harddisk recorders using fixed point? best, d. -- derek holzer ::: http://www.umatic.nl ---Oblique Strategy # 146: "Spectrum analysis"

21 years, 7 months

[linux-audio-dev] [ANN] swh-plugins 0.4.4

by Steve Harris

http://plugin.org.uk/releases/0.4.4/ * Fixes to build on recent gcc * New limiter for beter performance in JAMin * Denomal fixes from Tim Blechmann (general and specifially the flanger) * Many other things I've forgotten :( This release is largely untested, I released it because there are a number of important outstanding fixes. It may break some plugins, so beware. - Steve

21 years, 7 months

[linux-audio-dev] another jack q

by Dave Griffiths

Hi all, Bit of a dumb question I think, but I'm running jack realtime in softmode, and I'm getting sporadic cases of this: delay of 557251.000 usecs exceeds estimated spare time of 21355.000; restart ... too many consecutive interrupt delays ... engine pausing cycle execution failure, exiting DRIVER NT: could not run driver cycle jack main caught signal 12 Seems to run fine most of the time, but this appears repeatedly when it starts up occasionally, and shuts down jackd. I'm running quite old stuff here - jack (0.94.0) and audioslack ll kernel 2.4.21. Any ideas? cheers, dave

21 years, 7 months

[linux-audio-dev] updated VST/VSTi tutorial

by Dave Phillips

Greetings: I've recently updated my tutorial on using VST/VSTi plugins under Linux : http://www.djcj.org/LAU/quicktoots/toots/vst-plugins/ It now includes material regarding the fst project as well as the vstserver. Best regards, Dave Phillips

21 years, 7 months

[linux-audio-dev] libfishsound-0.6.3

by Conrad Parker

FishSound 0.6.3 Release ----------------------- libfishsound provides a simple programming interface for decoding and encoding audio data using Xiph.Org codecs (Vorbis and Speex). This release is available as a source tarball at: http://www.annodex.net/software/libfishsound/download/libfishsound-0.6.3.ta… This release fixes a bug in encoding to Speex format from a non-interleaved stereo PCM source, and closes a memory leak in the comments API. Additionally, the test suite has been expanded to cover all possible instances of encoding and decoding, and symmetrical trials of encode<->decode pipelines have been introduced. The test suite and example programs have also undergone rigorous testing of memory management and correctness of generated audio. About libfishsound ------------------ libfishsound by itself is designed to handle raw codec streams from a lower level layer such as UDP datagrams. When these codecs are used in files, they are commonly encapsulated in Ogg to produce Ogg Vorbis and Speex files. libfishsound is a wrapper around the existing codec libraries and provides a consistent, higher-level programming interface. It has been designed for use in a wide variety of applications; it has no direct dependencies on Annodex or Ogg encapsulation, though it is most commonly used in conjunction with liboggz to decode or encode Ogg encapsulated Vorbis or Speex files. FishSound has been developed and tested on GNU/Linux, Darwin/MacOSX and Win32. It probably also works on other Unix-like systems via GNU autoconf. For Win32: nmake Makefiles, Visual Studio .NET 2003 solution files and Visual C++ 6.0 workspace files are all provided in the source distribution. Full documentation of the FishSound API, customization and installation, and complete examples of Ogg Vorbis and Speex decoding and encoding are provided in the source tarball, and can be read online at: http://www.annodex.net/software/libfishsound/html/ FishSound is Free Software, available under a BSD-style license. More information is available online at the FishSound homepage: http://www.annodex.net/software/libfishsound/ enjoy :) -- Conrad Parker Senior Software Engineer, Continuous Media Web, CSIRO Australia http://www.annodex.net/ http://www.ict.csiro.au/cmweb/

21 years, 7 months

[linux-audio-dev] [ANN] TAP-plugins 0.6.0 +more

by Tom Szilagyi

TAP-plugins 0.6.0 released. TAP Reverb Editor initially released. Homepage: http://tap-plugins.sf.net OK, here we go: * New plugin: TAP Fractal Doubler. Suitable for doubling tracks containing vocals, acoustic/electric guitars, bass and just about any other instrument. The effect is created by applying small changes to the pitch and timing of the incoming signal. The changes are created by a one-dimensional random fractal line producing pink noise. Special thanks to Jan Depner for suggesting this plugin and pointing me to useful information about fractals. * New plugin: TAP Reflector. This plugin creates a psychedelic reverse audio effect. It is especially worth trying this plugin on sustained guitar and vocal tracks. Percussive sounds also create a very characteristic atmosphere when played in a backward-ish style. * New plugin: TAP Pink/Fractal Noise. This plugin came to life as a secondary product of the development of TAP Fractal Doubler. It generates pink noise by means of a one-dimensional random fractal line generated by the midpoint displacement method. Yes, it's Reverb time again! * Vastly enhanced the internal workings of TAP Reverberator. As a result, the sonic quality of reverberation got much better. (Well, at least, now it *IS* real reverberation.) If you tried it once, and found it sounded like hell, you definitely need to check it out now! * Long-long-standing denormal float (or whatever) problems causing occasional runaway CPU-usage led to the complete re-implementation of the internal DSP algorithm of the reverb using fixed-point arithmetics. This inherently fixes denormal problems. However, the option to use the previous floating-point DSP code remains as a #define which you can set before compiling. The default is to use fixed-point math. Very special thanks to Jan Depner for spending his time with repeatedly testing the reverb and sharing his insights. * A new application named TAP Reverb Editor has been written. It is a standalone JACK app, with a GTK+-2 user interface. It works and sounds the same as the LADSPA version (TAP Reverberator), but has extended features that support direct editing of Reverb Types, with immediate visual and sonic feedback. You can design new Reverb Types easily, and 'backporting' these into the LADSPA version is also a breeze. This program is available as a separate package called TAP-reverbed. * Introducing some new Reverb Types: I made these for some acoustic guitar tracks: * Ambience * Ambience (Thick) * Ambience (Thick) - HD ...and these for fun: * Cathedral * Cathedral - HD Other changes: * TAP Dynamics plugins (both Mono and Stereo) were also affected by a runaway CPU-usage issue. It was fixed in the same way as with the reverb: by converting the internals to use fixed point math by default. (The #define option to use floating point math still remains.) * Applied patch from Luke Yelavich to clean up the Makefile a bit. * Complete website/docs redesign. The documentation for TAP-plugins and the user manual for TAP Reverb Editor is now available for download as a separate package called TAP-plugins-doc. Hope you enjoy this release. Please report any problems. Tom

21 years, 7 months

[linux-audio-dev] Re: Audio over Ethernet / Livewire

by John Lazzaro

> From: Steve Harris <S.W.Harris(a)ecs.soton.ac.uk> > Subject: Re: [linux-audio-dev] Audio over Ethernet / Livewire > > [...] RTP-MIDI [...] Thanks, Steve. A lot of work has gone into RTP MIDI, to get consensus across a wide range of interests -- the IETF, MPEG, the MMA, and the computer music community. I should note we're not there yet (i.e. we haven't started the vetting process that ends, if successful, in RFCs) , but we're getting ever closer to Last Call (the start of the process). The most recent documents are here: http://www.cs.berkeley.edu/~lazzaro/sa/pubs/txt/current-rtp-midi.txt http://www.cs.berkeley.edu/~lazzaro/sa/pubs/txt/current-guide.txt Also note that the RTP-MIDI network stack in sfront: http://www.cs.berkeley.edu/~lazzaro/sa/index.html has been re-licensed under the BSD license, the stack resides in sfront/src/lib/nsys/. I also have the stack in a tar file that only contains BSD-licensed files -- let me know if you need a copy and I'll send it along. The stack is more for reading than for using -- I think the best RTP MIDI implementations will start with a clean slate. --- John Lazzaro http://www.cs.berkeley.edu/~lazzaro lazzaro [at] cs [dot] berkeley [dot] edu ---

21 years, 7 months

[linux-audio-dev] [ANN] TAP-plugins 0.6.0 +more

by Tom Szilagyi

21 years, 7 months

[linux-audio-dev] Audio over Ethernet / Livewire

by Frank van de Pol

While surfing the web I came across an interesting paper regarding Audio over Ethernet in low-latency low-jitter professional studio environments. I don't know to what extent the proposed scheme is open or patented or whatsoever. http://www.telos-systems.com/techtalk/ethernet4audio/NAB03_CHURCH_FINAL_2.p… Have fun, Frank. -- +---- --- -- - - - - | Frank van de Pol -o) A-L-S-A | FvdPol(a)coil.demon.nl /\\ Sounds good! | http://www.alsa-project.org _\_v | Linux - Why use Windows if we have doors available?

21 years, 7 months

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Linux-audio-dev