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Bug 649969 - [audiotestsrc] Add more noise variants
[audiotestsrc] Add more noise variants
Status: RESOLVED FIXED
Product: GStreamer
Classification: Platform
Component: gst-plugins-base
unspecified
Other Linux
: Normal enhancement
: 0.10.36
Assigned To: GStreamer Maintainers
GStreamer Maintainers
Depends on:
Blocks:
 
 
Reported: 2011-05-11 14:23 UTC by Stefan Sauer (gstreamer, gtkdoc dev)
Modified: 2011-06-15 17:42 UTC
See Also:
GNOME target: ---
GNOME version: ---



Description Stefan Sauer (gstreamer, gtkdoc dev) 2011-05-11 14:23:16 UTC
audiotestsrc can do
(5): white-noise      - White uniform noise
(6): pink-noise       - Pink noise
(9): gaussian-noise   - White Gaussian noise

http://en.wikipedia.org/wiki/Colors_of_noise knows more noise-flavours that could be added.
Comment 1 David Schleef 2011-05-11 20:24:04 UTC
Can we please rename "silence" to "black-noise"?
Comment 2 Sebastian Dröge (slomo) 2011-05-17 07:14:50 UTC
Is someone going to work on this?
Comment 3 Stefan Sauer (gstreamer, gtkdoc dev) 2011-05-17 10:05:03 UTC
(In reply to comment #1)
> Can we please rename "silence" to "black-noise"?

Seriously?

(In reply to comment #2)
> Is someone going to work on this?

If none else does, I will.
Brownian (Red) Noise: http://vellocet.com/dsp/noise/VRand.html
  // returns brown noise random number in the range -0.5 to 0.5
  //
  inline float brown(void)
  {
    while (true)
    {
      float  r = white();
      m_brown += r;
      if (m_brown<-8.0f || m_brown>8.0f) m_brown -= r;
      else break;
    }
    return m_brown*0.0625f;
  }

Blue should be white-pink and violet should be white-red if I don't overlook anything (need to verify the spectrum). Have not found anything for gray yet.
Comment 4 Stefan Sauer (gstreamer, gtkdoc dev) 2011-05-19 11:40:17 UTC
http://www.dsprelated.com/showmessage/4875/1.php (more links on the site)
Comment 5 Stefan Sauer (gstreamer, gtkdoc dev) 2011-05-25 20:40:52 UTC
commit 1cf831e74ec1231137ec3cbbd8b8cab5eb0c4749
Author: Stefan Kost <ensonic@users.sf.net>
Date:   Wed May 25 23:40:26 2011 +0300

    audiotestsrc: add red (brownian) noise generator
    
    Add another noise generator which produces a quite dark noise color.
    
    Fixes parts of #649969.
Comment 6 Stefan Sauer (gstreamer, gtkdoc dev) 2011-05-25 21:14:21 UTC
commit 5cd0e0f666699e9c49ee4f9646118b596cd351ed
Author: Stefan Kost <ensonic@users.sf.net>
Date:   Thu May 26 00:17:40 2011 +0300

    audiotestsrc: add blue and violet noise by using spectral inversion
    
    Add blue and violet noise by spectral inversion of pink and red noise.
    Fixes #649969