[PATCH] favor ffmpeg over deprecated avconv

[Eric Wong <e@80x24.org>]

When this project started avconv was favored in Debian,
but that hasn't been the case in many years.  Increase
the priority of ffmpeg to match the current situation in
Debian.
---
 Documentation/dtas-player.pod     |  10 +--
 Documentation/dtas-sourceedit.pod |   8 +--
 lib/dtas/source/av.rb             |   6 +-
 lib/dtas/source/av_ff_common.rb   |   8 +--
 lib/dtas/source/ff.rb             |   7 +-
 test/test_source_ff.rb            | 102 ++++++++++++++++++++++++++++++
 6 files changed, 117 insertions(+), 24 deletions(-)
 create mode 100644 test/test_source_ff.rb

diff --git a/Documentation/dtas-player.pod b/Documentation/dtas-player.pod
index 932441a..4cfdd12 100644
--- a/Documentation/dtas-player.pod
+++ b/Documentation/dtas-player.pod
@@ -70,10 +70,10 @@ To play audio on my favorite USB DAC directly to ALSA, I use:
 =head2 Seeking/playing audio from large video containers (e.g. VOB) fails
 
 This is a problem with large VOBs.  We recommend breaking up the
-VOB into smaller files or using L<avconv(1)> or L<ffmpeg(1)> to extract
-the desired audio stream.
+VOB into smaller files or using L<ffmpeg(1)> to extract
+the desired audio stream at C<$STREAM_NR>.
 
-      avconv -analyzeduration 2G -probesize 2G \
+      ffmpeg -analyzeduration 2G -probesize 2G \
         -i input.vob -vn -sn -c:a copy -map 0:$STREAM_NR output.ext
 
 =head1 ADVANCED EXAMPLES
@@ -115,7 +115,7 @@ No subscription is necessary to post to the mailing list.
 
 =head1 COPYRIGHT
 
-Copyright 2013-2020 all contributors L<mailto:dtas-all@nongnu.org>
+Copyright all contributors L<mailto:dtas-all@nongnu.org>
 
 License: GPL-3.0+ L<https://www.gnu.org/licenses/gpl-3.0.txt>
 
@@ -123,4 +123,4 @@ License: GPL-3.0+ L<https://www.gnu.org/licenses/gpl-3.0.txt>
 
 L<dtas-player_protocol(7)>, L<dtas-ctl(1)>, L<dtas-enq(1)>,
 L<dtas-sourceedit(1)>, L<dtas-sinkedit(1)>, L<sox(1)>, L<play(1)>,
-L<avconv(1)>, L<ffmpeg(1)>, L<screen(1)>, L<tmux(1)>
+L<ffmpeg(1)>, L<screen(1)>, L<tmux(1)>
diff --git a/Documentation/dtas-sourceedit.pod b/Documentation/dtas-sourceedit.pod
index 67ecabf..593bcf5 100644
--- a/Documentation/dtas-sourceedit.pod
+++ b/Documentation/dtas-sourceedit.pod
@@ -51,11 +51,7 @@ of a previous "dtas-ctl source cat sox" invocation:
 
 	$ dtas-sourceedit sox < saved.yml
 
-To change the way dtas-player calls avconv (part of libav):
-
-	$ dtas-sourceedit av
-
-To change the way dtas-player calls ffmpeg (lightly-tested):
+To change the way dtas-player calls ffmpeg:
 
 	$ dtas-sourceedit ff
 
@@ -77,7 +73,7 @@ No subscription is necessary to post to the mailing list.
 
 =head1 COPYRIGHT
 
-Copyright 2013-2020 all contributors L<mailto:dtas-all@nongnu.org>
+Copyright all contributors L<mailto:dtas-all@nongnu.org>
 
 License: GPL-3.0+ L<https://www.gnu.org/licenses/gpl-3.0.txt>
 
diff --git a/lib/dtas/source/av.rb b/lib/dtas/source/av.rb
index 823b29f..dcebcfd 100644
--- a/lib/dtas/source/av.rb
+++ b/lib/dtas/source/av.rb
@@ -1,4 +1,4 @@
-# Copyright (C) 2013-2020 all contributors <dtas-all@nongnu.org>
+# Copyright (C) all contributors <dtas-all@nongnu.org>
 # License: GPL-3.0+ <https://www.gnu.org/licenses/gpl-3.0.txt>
 # frozen_string_literal: true
 require_relative '../../dtas'
@@ -13,9 +13,7 @@ class DTAS::Source::Av # :nodoc:
       'avconv -v error $SSPOS $PROBE -i "$INFILE" $AMAP -f sox - |' \
       'sox -p $SOXFMT - $TRIMFX $RGFX',
 
-    # this is above ffmpeg because this av is the Debian default and
-    # it's easier for me to test av than ff
-    "tryorder" => 1,
+    "tryorder" => 2,
   )
 
   def initialize
diff --git a/lib/dtas/source/av_ff_common.rb b/lib/dtas/source/av_ff_common.rb
index 3839272..c600c48 100644
--- a/lib/dtas/source/av_ff_common.rb
+++ b/lib/dtas/source/av_ff_common.rb
@@ -7,10 +7,10 @@
 require_relative '../xs'
 require_relative 'file'
 
-# Common code for libav (avconv/avprobe) and ffmpeg (and ffprobe)
-# TODO: newer versions of both *probes support JSON, which will be easier to
-# parse.  However, the packaged libav version in Debian 7.0 does not
-# support JSON, so we have an ugly parser...
+# Common code for ffmpeg/ffprobe and the abandoned libav (avconv/avprobe).
+# TODO: newer versions of both *probes support JSON, which will be easier
+# to parse.  libav is abandoned, nowadays, and Debian only packages
+# ffmpeg+ffprobe nowadays.
 module DTAS::Source::AvFfCommon # :nodoc:
   include DTAS::Source::File
   include DTAS::XS
diff --git a/lib/dtas/source/ff.rb b/lib/dtas/source/ff.rb
index 491e580..c337b42 100644
--- a/lib/dtas/source/ff.rb
+++ b/lib/dtas/source/ff.rb
@@ -1,12 +1,10 @@
-# Copyright (C) 2013-2020 all contributors <dtas-all@nongnu.org>
+# Copyright (C) all contributors <dtas-all@nongnu.org>
 # License: GPL-3.0+ <https://www.gnu.org/licenses/gpl-3.0.txt>
 # frozen_string_literal: true
 require_relative '../../dtas'
 require_relative 'av_ff_common'
 
 # ffmpeg support
-# note: only tested with the compatibility wrapper in the Debian 7.0 package
-# (so still using avconv/avprobe)
 class DTAS::Source::Ff  # :nodoc:
   include DTAS::Source::AvFfCommon
 
@@ -15,8 +13,7 @@ class DTAS::Source::Ff  # :nodoc:
       'ffmpeg -v error $SSPOS $PROBE -i "$INFILE" $AMAP -f sox - |' \
       'sox -p $SOXFMT - $TRIMFX $RGFX',
 
-    # I haven't tested this much since av is in Debian stable and ff is not
-    "tryorder" => 2,
+    "tryorder" => 1,
   )
 
   def initialize
diff --git a/test/test_source_ff.rb b/test/test_source_ff.rb
new file mode 100644
index 0000000..e53e72e
--- /dev/null
+++ b/test/test_source_ff.rb
@@ -0,0 +1,102 @@
+# Copyright (C) all contributors <dtas-all@nongnu.org>
+# License: GPL-3.0+ <https://www.gnu.org/licenses/gpl-3.0.txt>
+# frozen_string_literal: true
+require './test/helper'
+require 'dtas/source/ff'
+require 'tempfile'
+
+class TestSourceFf < Testcase
+  def teardown
+    @tempfiles.each(&:close!)
+  end
+
+  def setup
+    @tempfiles = []
+  end
+
+  def x(cmd)
+    system(*cmd)
+    assert $?.success?, cmd.inspect
+  end
+
+  def new_file(suffix)
+    tmp = Tempfile.new(%W(tmp .#{suffix}))
+    @tempfiles << tmp
+    cmd = %W(sox -r 44100 -b 16 -c 2 -n #{tmp.path} trim 0 1)
+    return tmp if system(*cmd)
+    nil
+  end
+
+  def test_flac
+    return if `which metaflac`.strip.size == 0
+    tmp = new_file('flac') or return
+
+    x(%W(metaflac --set-tag=FOO=BAR #{tmp.path}))
+    x(%W(metaflac --add-replay-gain #{tmp.path}))
+    source = DTAS::Source::Ff.new.try(tmp.path)
+    assert_equal source.comments["FOO"], "BAR", source.inspect
+    rg = source.replaygain('track_gain')
+    assert_kind_of DTAS::ReplayGain, rg
+    assert_in_delta 0.0, rg.track_peak.to_f, 0.00000001
+    assert_in_delta 0.0, rg.album_peak.to_f, 0.00000001
+    assert_operator rg.album_gain.to_f, :>, 1
+    assert_operator rg.track_gain.to_f, :>, 1
+  end
+
+  def test_mp3gain
+    return if `which mp3gain`.strip.size == 0
+    a = new_file('mp3') or return
+    b = new_file('mp3') or return
+
+    # redirect stdout to /dev/null temporarily, mp3gain is noisy
+    File.open("/dev/null", "w") do |null|
+      old_out = $stdout.dup
+      $stdout.reopen(null)
+      begin
+        x(%W(mp3gain -q #{a.path} #{b.path}))
+      ensure
+        $stdout.reopen(old_out)
+        old_out.close
+      end
+    end
+
+    source = DTAS::Source::Ff.new.try(a.path)
+    rg = source.replaygain('track_gain')
+    assert_kind_of DTAS::ReplayGain, rg
+    assert_in_delta 0.0, rg.track_peak.to_f, 0.00000001
+    assert_in_delta 0.0, rg.album_peak.to_f, 0.00000001
+    assert_operator rg.album_gain.to_f, :>, 1
+    assert_operator rg.track_gain.to_f, :>, 1
+  end
+
+  def test_offset
+    tmp = new_file('flac') or return
+    source = DTAS::Source::Ff.new.try(*%W(#{tmp.path} 5s))
+    assert_equal 5, source.offset_samples
+
+    source = DTAS::Source::Ff.new.try(*%W(#{tmp.path} 1:00:00.5))
+    expect = 1 * 60 * 60 * 44100 + (44100/2)
+    assert_equal expect, source.offset_samples
+
+    source = DTAS::Source::Ff.new.try(*%W(#{tmp.path} 1:10.5))
+    expect = 1 * 60 * 44100 + (10 * 44100) + (44100/2)
+    assert_equal expect, source.offset_samples
+
+    source = DTAS::Source::Ff.new.try(*%W(#{tmp.path} 10.03))
+    expect = (10 * 44100) + (44100 * 3/100.0)
+    assert_equal expect, source.offset_samples
+  end
+
+  def test_offset_us
+    tmp = new_file('flac') or return
+    source = DTAS::Source::Ff.new.try(*%W(#{tmp.path} 441s))
+    assert_equal 10000.0, source.offset_us
+
+    source = DTAS::Source::Ff.new.try(*%W(#{tmp.path} 22050s))
+    assert_equal 500000.0, source.offset_us
+
+    source = DTAS::Source::Ff.new.try(tmp.path, '1')
+    assert_equal 1000000.0, source.offset_us
+  end
+end if `which ffprobe 2>/dev/null` =~ /ffprobe/ &&
+       `which ffmpeg 2>/dev/null` =~ /ffmpeg/