From 37eae22446feb5a805d9cd59f6ad54362829189f Mon Sep 17 00:00:00 2001
From: Eric Wong <e@80x24.org>
Date: Wed, 28 Jan 2015 07:44:05 +0000
Subject: player: support the "trim" parameter

This feature is intended to allow users to "zoom-in" on a
particular portion of a track to tweak parameters (either
with dtas-sourceedit(1) or via playback of splitfx YAML files).
This may be combined with looping the tracklist
(via "tl repeat").
---
 lib/dtas/source/av_ff_common.rb | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

(limited to 'lib/dtas/source/av_ff_common.rb')

diff --git a/lib/dtas/source/av_ff_common.rb b/lib/dtas/source/av_ff_common.rb
index 03526d2..189e135 100644
--- a/lib/dtas/source/av_ff_common.rb
+++ b/lib/dtas/source/av_ff_common.rb
@@ -19,8 +19,8 @@ module DTAS::Source::AvFfCommon # :nodoc:
   attr_reader :precision # always 32
   attr_reader :format
 
-  def try(infile, offset = nil)
-    rv = source_file_dup(infile, offset)
+  def try(infile, offset = nil, trim = nil)
+    rv = source_file_dup(infile, offset, trim)
     rv.av_ff_ok? or return
     rv
   end
@@ -101,10 +101,20 @@ module DTAS::Source::AvFfCommon # :nodoc:
     ! @astreams.compact.empty?
   end
 
-  def sspos(offset)
-    offset =~ /\A(\d+)s\z/ or return "-ss #{offset}"
-    samples = $1.to_f
-    sprintf("-ss %0.9g", samples / @format.rate)
+  def sspos
+    return unless @offset || @trim
+    off = offset_samples / @format.rate.to_f
+    sprintf('-ss %0.9g', off)
+  end
+
+  def av_ff_trimfx # for sox
+    return unless @trim
+    tbeg, tlen = @trim # Floats
+    tend = tbeg + tlen
+    off = offset_samples / @format.rate.to_f
+    tlen = tend - off
+    tlen = 0 if tlen < 0
+    sprintf('trim 0 %0.9g', tlen)
   end
 
   def select_astream(as)
@@ -150,8 +160,9 @@ module DTAS::Source::AvFfCommon # :nodoc:
     # make sure these are visible to the source command...
     e["INFILE"] = @infile
     e["AMAP"] = amap
-    e["SSPOS"] = @offset ? sspos(@offset) : nil
+    e["SSPOS"] = sspos
     e["RGFX"] = rg_state.effect(self) || nil
+    e["TRIMFX"] = av_ff_trimfx
     e.merge!(@rg.to_env) if @rg
 
     @pid = dtas_spawn(e, command_string, opts)
-- 
cgit v1.2.3-24-ge0c7