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IR convolution

Anonymous
2010-02-25
2013-05-28

  • Anonymous
    2010-02-25

    Are there any plans to implement Impulse Response convolution? It would be interesting to have it implemented in a changeable fashion, not like guitarix does.

     
  • Transmogrifox
    Transmogrifox
    2010-02-25

    I have been considering this.  A convolution algorithm itself is easy, as it's only an FIR filter.  Changing it "hot" is also easy.  Sometime around the release of 0.4.2, Josep and I were talking about it in IRC.  I don't know when exactly this will be added, but this is definitely laying on the table.

     
  • Transmogrifox
    Transmogrifox
    2010-02-26

    Hey, you pushed us over the edge.  Josep and I went to coding and came up with a rakarrack module able to do convolution. You can use it if you compile from git.  It is very preliminary right now, but it will improve dramatically over the next little bit now.  At the moment it uses some IR files that are hard-coded, but plan to add an option to browse for your own.

    The sound you'll notice is a little rough in this infancy stage.  There needs to be an envelope applied to trim the tail off the unused part of the IR.  As is the classic problem, your CPU won't handle any more than 100ms IR unless you have an incredible computer.  I'll be adding a computationally efficient way to handle longer IR's for things like reverb and room responses.

     
  • Transmogrifox
    Transmogrifox
    2010-02-26

    …and if you want to try your own IR files, you probably have to save over the sample files in the source.  you would then change preset and it would select whatever file is being pointed to…You can change "hot", but you have to do it by overwriting the sample file with the same file name :)

     
  • Transmogrifox
    Transmogrifox
    2010-02-26

    …one last note :)  do realize this isn't the way it is going to be….this is just while it is in testing phase.  We are developing continually…so if you keep up with git, you will get improvements as they come :)