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faq:start [2012/03/18 17:36] – rootfaq:start [2016/03/20 12:28] – [Q: Is it possible to run VST plugins on Linux?] Replace dead link, mark another link as deprecated content spotlightkid
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 ====== Linux Audio User FAQ (Frequently Asked Questions) ====== ====== Linux Audio User FAQ (Frequently Asked Questions) ======
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-. 
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 ===== General ===== ===== General =====
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 [[wiki:real_time_info|Articles and more information about real time operation]]. [[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.
 +
 +
 +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.
 ==== 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.
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   * [[http://en.wikipedia.org/wiki/Audio_restoration| wikipedia - Audio restoration]]   * [[http://en.wikipedia.org/wiki/Audio_restoration| wikipedia - Audio restoration]]
   * [[http://wiki.librivox.org/index.php/Detailed_Audacity_Noise_Removal| librivox wiki - Detailed: Noise removal with Audacity]]   * [[http://wiki.librivox.org/index.php/Detailed_Audacity_Noise_Removal| librivox wiki - Detailed: Noise removal with Audacity]]
 +  * [[http://www.cedaraudio.com/| CedarAudio Company ]] - with some tech. info
 **Applications** **Applications**
   * [[http://gwc.sourceforge.net/| The Gnome Wave Cleaner Project]]   * [[http://gwc.sourceforge.net/| The Gnome Wave Cleaner Project]]
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 ==== 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.
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 (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
  
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   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
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 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/]]
  
  
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 **A:** A buffer is not filled in time for the requesting software to use it. Sound data does not arrive fast enough so that the requesting software has a continuous stream of data, in other words, the requesting software runs out of sound data. This is because some part of the system is not fast enough to keep up. **A:** A buffer is not filled in time for the requesting software to use it. Sound data does not arrive fast enough so that the requesting software has a continuous stream of data, in other words, the requesting software runs out of sound data. This is because some part of the system is not fast enough to keep up.
 +
 +An obvious fix for this is increasing the period size. If you're running jack with 128, for example, and you're getting regular X-runs, then increasing the size to 256 may help immediately, and solve the problem.
 +
  
 ===== MIDI ===== ===== MIDI =====
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 **Related sites:** **Related sites:**
-  * [[http://quicktoots.linuxaudio.org/toots/vst-plugins/]] - a more detailed introduction +  * [[http://linux-sound.org/linux-vst-plugins.html]] - VST/VSTi Plugins For Linux 
-  * [[http://ladspavst.linuxaudio.org/]] - Linux Compatibility of Plugins+  * [[http://quicktoots.linuxaudio.org/toots/vst-plugins/]] - a more detailed introduction (**Depretcated** page)
  
-**Note:** Instead of VST, you will soon prefere to use **Linux plugin technologie** :-) [[apps:all:LADSPA]], [[apps:all:DSSI]] and [[apps:categories:LV2]]+**Note:** Instead of VST, you may prefer to use **Linux plugin technologies** like [[apps:categories:LV2 | LV2]], [[apps:all:LADSPA]], and [[apps:all:DSSI]].
  
  
  
 {{tag>howtos_and_faqs}} {{tag>howtos_and_faqs}}
faq/start.txt · Last modified: 2017/08/26 17:21 by jeb_ponderworthy.com