From 27157b3a8cf6d2e37d80dfa130b56711dcb8cd28 Mon Sep 17 00:00:00 2001
From: Eric Wong <normalperson@yhbt.net>
Date: Thu, 17 Oct 2013 06:36:28 +0000
Subject: fadefx: initial commit

This allows parsing and will eventually interact with trimfx.
---
 lib/dtas/fadefx.rb | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 lib/dtas/fadefx.rb

(limited to 'lib')

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
-- 
cgit v1.2.3-24-ge0c7