3 files changed, 9 insertions, 0 deletions
diff --git a/lib/dtas/source/av_ff_common.rb b/lib/dtas/source/av_ff_common.rb
index 0fb3ace..58d9f54 100644
--- a/lib/dtas/source/av_ff_common.rb
+++ b/lib/dtas/source/av_ff_common.rb
@@ -19,6 +19,7 @@ module DTAS::Source::AvFfCommon # :nodoc:
  
    attr_reader :precision # always 32
    attr_reader :format
+  attr_reader :duration
  
    def try(infile, offset = nil, trim = nil)
      rv = source_file_dup(infile, offset, trim)
diff --git a/lib/dtas/source/sox.rb b/lib/dtas/source/sox.rb
index 9d128a6..db1ace2 100644
--- a/lib/dtas/source/sox.rb
+++ b/lib/dtas/source/sox.rb
@@ -53,6 +53,10 @@ class DTAS::Source::Sox # :nodoc:
      @format ||= DTAS::Format.from_file(@env, @infile)
    end
  
+  def duration
+    samples / format.rate.to_f
+  end
+
    # This is the number of samples according to the samples in the source
    # file itself, not the decoded output
    def samples
diff --git a/lib/dtas/source/splitfx.rb b/lib/dtas/source/splitfx.rb
index d824959..f746bee 100644
--- a/lib/dtas/source/splitfx.rb
+++ b/lib/dtas/source/splitfx.rb
@@ -107,6 +107,10 @@ class DTAS::Source::SplitFX < DTAS::Source::Sox # :nodoc:
      @sox.samples
    end
  
+  def duration
+    @sox.duration
+  end
+
    def source_defaults
      SPLITFX_DEFAULTS
    end