Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revisionPrevious revision
Next revision		Previous revision
faq:start [2012/05/25 20:09] – [Q: How to remove noise ? How to restore old recordings (from vinyl/tape) ?] emrumfaq:start [2017/08/26 15:21] (current) – [Q: How to remove noise from recordings? How to restore old recordings (from vinyl/tape)?] jeb_ponderworthy.com
Line 1: Line 1:
 ====== Linux Audio User FAQ (Frequently Asked Questions) ====== ====== Linux Audio User FAQ (Frequently Asked Questions) ======
- 
-. 
- 
-. 
  
 ===== General ===== ===== General =====
Line 13: Line 9:
 ==== Q: How to optimize my system for audio / midi ? ==== ==== Q: How to optimize my system for audio / midi ? ====
  
-**A:** <del>Using a "real-time kernel" and setting priorities appropriate is an important step here</del>. This has often been told, but according to the jackd FAQ it is simply not true! See [[http://jackaudio.org/realtime_vs_realtime_kernel]] +**A:** For some uses, it can be helpful to run a realtime (RT) kernel, but generally this isn't necessary anymore. See the following JACK FAQ entry: [[http://jackaudio.org/faq/realtime_vs_realtime_kernel.html | Do I need a realtime kernel to use realtime scheduling?]]
-[[wiki:real_time_info|Articles and more information about real time operation]].+
  
 +In Linux kernels 3.0 and later, many of the additionally required realtime patches have been incorporated as standard. For those who are recording Audio, a standard non-realtime kernel may be sufficient for your needs, and running Jack with a non realtime kernel will work fine.
  
-In linux kernels 3.0 and later, many of the additionally required realtime patches have been incorporated as standard. For those who are recording Audio, a standard non-realtime kernel may be sufficient for your needs, and running Jack with a non realtime kernel will work fine.+You need to configure your system, however, to [[http://jackaudio.org/faq/linux_rt_config.html | allow JACK to use realtime scheduling]].
  
 +This wiki has some more [[wiki:real_time_info | articles and general information]] about real time operation.
  
-For those who write a lot of Midi, the standard kernel timing is set at 250Hz, and realtime kernels are generally set at 1000Hz. You may still have to use a realtime kernel to obtain accurate midi playback using the higher timing setting.+Those who produce a lot of MIDI I/O, may want to use a Linux kernel with non-standard timer interrupt frequency (aka "tick rate"). The standard frequency is set at 250 Hz, and realtime kernels are generally set at 1000 Hz. You may still have to use a realtime kernel to obtain accurate MIDI playback using the higher timing setting.
 ==== Q: Some of my applications sound a (half)tone too high/low, have a wrong pitch ? ==== ==== Q: Some of my applications sound a (half)tone too high/low, have a wrong pitch ? ====
 **A:** It's likely, that the sample-rate of the programs you're using doesn't match. **A:** It's likely, that the sample-rate of the programs you're using doesn't match.
Line 28: Line 25:
  
  
-==== Q: How to remove noise ? How to restore old recordings (from vinyl/tape) ? ====+==== Q: How to remove noise from recordings? How to restore old recordings (from vinyl/tape)? ====
 Some noises can be removed by surpressing specific frequencies, by applying EQs or Filters. Some noises can be removed by surpressing specific frequencies, by applying EQs or Filters.
 Audiofile editors as audacity and rezound offer different solutions for noise removal. Audiofile editors as audacity and rezound offer different solutions for noise removal.
Line 46: Line 43:
   * [[http://www.muenchen-surf.de/mpaar/| "Declick 2000" plugin - not open source, but priceless]]   * [[http://www.muenchen-surf.de/mpaar/| "Declick 2000" plugin - not open source, but priceless]]
  
 +==== Q: How to eliminate noise from live production? ====
 +Live noise has many causes, including ground-loops, and other equipment near and far injecting static of many kinds.  This includes including weak but audio-active USB signals, PC fan noise, firewire, et cetera, into powerline, ground, and thence into the system.  There are many approaches to this, and often more than one approach is needed.
  
 +**Related articles** 
 +  * [[http://www.audioholics.com/home-theater-connection/ground-loops-eliminating-system-hum-and-buzz|Ground Loops - Eliminating System Hum and Buzz]] 
 +  * [[http://lsn.ponderworthy.com/doku.php/cleaning_the_tone|Cleaning the Tone]]
  
 ==== Q: What about timers and timing ? ==== ==== Q: What about timers and timing ? ====
-Modern PCs provide good hardware timing sources. +For moderate to new hardware, TSC is the best hardware timing sources.  Old hardware may have timing issues with multi-core CPU where HPET (high-precision-event-timer) is preferable.
-One of it is the RTC (real-time-clock). Another one is the HPET (high-precision-event-timer), which is preferable due to higher accuracy.+
 Then there is a software layer (in the kernel) to make available the hw-timers to the applications, through different interfaces. Then there is a software layer (in the kernel) to make available the hw-timers to the applications, through different interfaces.
 One example is the usual system-timer. One example is the usual system-timer.
Line 63: Line 63:
 (see: priority settings, rtirq). (see: priority settings, rtirq).
  
-**How to know, if a HPET (hardware) is available?**+**How to know, if a TSC / HPET (hardware) is available?** 
 +  dmesg | grep -i tsc
   dmesg | grep -i hpet   dmesg | grep -i hpet
  
Line 69: Line 70:
   cat /proc/asound/timers   cat /proc/asound/timers
  
-**Related Kernel Options **+**How to config kernel for HPET?**
 <code> <code>
 # cat .config | grep -i hpet # cat .config | grep -i hpet
Line 89: Line 90:
 Related Articles: Related Articles:
 [[http://kerneltrap.org/node/6750| Article at kerneltrap.org]] [[http://kerneltrap.org/node/6750| Article at kerneltrap.org]]
 +[[http://btorpey.github.io/blog/2014/02/18/clock-sources-in-linux/]]
  
  
Line 308: Line 310:
  
 ==== Q: Is it possible to run VST plugins on Linux? ==== ==== Q: Is it possible to run VST plugins on Linux? ====
-**A:** Yes, there are different solutions: +**A:** First one has to distinguish between **native** Linux VST plug-ins and VST plugins built for other operating system (usually Windows). There is a growing number of native Linux plugins, which are available in VST format (see "Further resources" below) and an also growing number of host software for Linux supports native Linux VST plugins (see list below). Also there are some hosts or additional tools, which allow to run Windows VST plugins on Linux.
-  * [[http://www.joebutton.co.uk/fst/| fst-vst ]] +
-  * [[http://www.breakfastquay.com/dssi-vst/| dssi-vst ]] +
-  * wine with jack driver and a windows vst-host +
-  * wine with wine-asio to jack driver and a windows vst-host (see: [[http://wiki.jacklab.net/index.php/WineAsio_guide| WineAsio Guide]], [[http://people.jacklab.net/edogawa/files/wineasio/| wineasio download]], [[http://proaudio.tuxfamily.org/wiki/index.php?title=ASIO_with_Wineasio| Gentoo wineasio info]] +
-  * linux-native vst pluins (only availabe for open-sourced VSTs that compile on linux) (see: [[http://www.anticore.org/jucetice/?page_id=4|Jost]] )+
  
 +Windows VST plugins often come as two versions built for either 32-bit or 64-bit platforms. Some of the aforementioned tools only support 32-bit plugins, some both versions.
  
-**List of windows vst-hosts:**+If a Windows VST plugin doesn't work with any of the tools listed below, it is also possible to run a Windows VST host program under Linux via Wine and route its audio output to JACK (with or without WineASIO). 
 + 
 +**Note:** Instead of VST, you may prefer to use open plugin technologies like [[apps:categories:LV2 | LV2]], [[apps:all:LADSPA]], and [[apps:all:DSSI]]. 
 + 
 +**Linux VST hosts:** 
 + 
 +Open Source: 
 + 
 +  * [[http://ardour.org | Ardour]] 
 +  * [[http://www.audacityteam.org/ | Audacity]] 
 +  * [[http://kxstudio.linuxaudio.org/Applications:Carla | Carla]] 
 +  * [[http://www.anticore.org/jucetice/?page_id=4 | Jost]] 
 +  * [[https://lmms.io/ | LMMS]] 
 +  * [[http://www.muse-sequencer.org/ | Muse Sequencer]] 
 +  * [[http://qtractor.sourceforge.net/ | Qtractor]] 
 +  * [[http://users.notam02.no/~kjetism/radium/ | Radium]] 
 + 
 +Proprietary: 
 + 
 +  * [[http://www.bitwig.com/ | Bitwig]] 
 +  * [[http://energy-xt.com/ | energyXT]] 
 +  * [[http://www.renoise.com/  | Renoise]] 
 +  * [[http://tracktion.com | Tracktion]] 
 + 
 +**Note:** Some Linux plugin hosts only provide VST support, if you enable it at compile time with appropriate options. 
 + 
 + 
 +**Linux-Hosts with Windows VST support:** 
 + 
 +  * [[http://kxstudio.linuxaudio.org/Applications:Carla | Carla]] 
 +  * [[http://www.breakfastquay.com/dssi-vst/| dssi-vst]] 
 +  * [[http://www.joebutton.co.uk/fst/| fst-vst]] 
 + 
 +**Windows VST hosts:** 
 + 
 +  * [[http://www.reaper.fm/ | REAPER]]
   * [[http://www.hermannseib.com/|VSTHost and SAVIHost by Hermann Seib (source available !)]]   * [[http://www.hermannseib.com/|VSTHost and SAVIHost by Hermann Seib (source available !)]]
-  * [[http://www.dontcrack.com/freeware/downloads.php/id/4228/software/MiniHost/| MiniHost by Tobybear]] +  * [[http://www.tobybear.de/files.html | MiniHost by Tobybear]] 
-  * [[http://www.dontcrack.com/freeware/downloads.php/id/4076/software/MissWatson/| MissWatson (command-line) ]]+  * [[http://teragonaudio.com/MrsWatson | MrsWatson]] (command-line)
   * [[http://www.kreatives.org/kristal/|KRISTAL Audio Engine by Matthias Juwan (free for non-commercial) ]]   * [[http://www.kreatives.org/kristal/|KRISTAL Audio Engine by Matthias Juwan (free for non-commercial) ]]
  
-**List of linux vst-hosts:** 
-  * [[http://www.anticore.org/jucetice/?page_id=4| Jost linux native VST-Host ]] 
-  * Note: Some linux-apps can run vst plugins, if they are being compiled with appropriate options. 
  
 +**Running Windows VST hosts on Linux**
 +
 +  * Using Wine with its ALSA driver (optionally [[http://gamesplusone.com/alsa_to_jack.html | forwarding Wine's ALSA output to JACK]]).
 +  * Using Wine with WineASIO to JACK driver:
 +    * [[http://wineasio.sourceforge.net/ | WineASIO homepage]]
 +    * [[https://lkubuntu.wordpress.com/2014/01/09/how-to-set-up-wineasio/ | How to setup WineASIO]] (Ubuntu and Arch Linux)
 +    * [[http://proaudio.tuxfamily.org/wiki/index.php?title=ASIO_with_Wineasio| Gentoo WineASIO info]]
  
-**Related sites:** 
-  * [[http://quicktoots.linuxaudio.org/toots/vst-plugins/]] - a more detailed introduction 
-  * [[http://ladspavst.linuxaudio.org/]] - Linux Compatibility of Plugins 
  
-**Note:** Instead of VST, you will soon prefere to use **Linux plugin technologie** :-) [[apps:all:LADSPA]], [[apps:all:DSSI]] and [[apps:categories:LV2]]+**Further resources:**
  
 +  * [[http://linux-sound.org/linux-vst-plugins.html]] - VST/VSTi Plugins For Linux
 +  * [[http://quicktoots.linuxaudio.org/toots/vst-plugins/]] - a more detailed introduction (**Deprecated** page)
  
  
 {{tag>howtos_and_faqs}} {{tag>howtos_and_faqs}}
faq/start.1337976563.txt.gz · Last modified: by emrum