Differences

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

--- faq:start [2011/06/22 16:25] – emrum
+++ faq:start [2013/07/16 23:33] – the_aviv
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 ====== Linux Audio User FAQ (Frequently Asked Questions) ======
-.
-.
 ===== General =====
@@ Line 16: / Line 12: @@
 [[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 ? ====
 **A:** It's likely, that the sample-rate of the programs you're using doesn't match.
@@ Line 33: / Line 34: @@
   * [[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://www.cedaraudio.com/| CedarAudio Company ]] - with some tech. info
 **Applications**
   * [[http://gwc.sourceforge.net/| The Gnome Wave Cleaner Project]]
@@ Line 133: / Line 135: @@
-==== Q: How to setup the JACK audio server? (jackd) ====
+==== Q: How to set up the JACK audio server? (jackd) ====
@@ Line 148: / Line 150: @@
 ==== Q: What is an xrun? ====
-**A:** A buffer-underflow (a buffer (a count of bytes or samples) is requested that has not been filled yet)
+**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.
-//Wouldn't it be more accurate to say something like: "a buffer is not filled in time for the requesting software to use it"--or "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" (possibly adding "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 =====
@@ Line 204: / Line 203: @@
 is what you see in the 'MIDI' tab in qjackctl.
-**Currently the two midi routing system coexist, and this
+**Currently the two MIDI routing systems coexist, and this
 leads to some confusion.**
@@ Line 296: / Line 295: @@
 (on debian/ubuntu: apt-get install midisport-firmware alsa-firmware-loaders)
-Due to a missing audio standard for USB 2.0, support for USB 2.0 devices is less than rare (~non-existent for soundcards).
+Support for USB 2.0 devices is also increasingly common.
 .
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+{{tag>howtos_and_faqs}}