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Diffstat (limited to 'lib/dtas/fadefx.rb')
-rw-r--r-- | lib/dtas/fadefx.rb | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/lib/dtas/fadefx.rb b/lib/dtas/fadefx.rb new file mode 100644 index 0000000..7e0e65f --- /dev/null +++ b/lib/dtas/fadefx.rb @@ -0,0 +1,32 @@ +# Copyright (C) 2013, Eric Wong <normalperson@yhbt.net> and all contributors +# License: GPLv3 or later (https://www.gnu.org/licenses/gpl-3.0.txt) +require_relative '../dtas' +require_relative 'parse_time' + +class DTAS::FadeFX + include DTAS::ParseTime + attr_reader :out_prev, :in_main, :out_main, :in_next + F = Struct.new(:type, :len) + + def initialize(args) + args =~ /\Afade=([^,]*),([^,]*);([^,]*),([^,]*)\z/ or + raise ArgumentError, "bad fade format" + fades = [ $1, $2, $3, $4 ] + %w(out_prev in_main out_main in_next).each do |iv| + instance_variable_set("@#{iv}", parse!(fades.shift)) + end + end + + # q - quarter of a sine wave + # h - half a sine wave + # t - linear (`triangular') slope + # l - logarithmic + # p - inverted parabola + # default is 't' (sox defaults to 'l', but triangular makes more sense + # when concatenating + def parse!(str) + type = "t" + str.sub!(/\A([a-z])/, "") and type = $1 + F[type, parse_time(str)] + end +end |