music-battery-test

#!/usr/bin/env ruby

$TEST_PERIOD = 60 * 61
$SAMPLE_PERIOD = 60 * 10
$CAPACITY = 1320
$RS = 20

class Array
  def mean
    self.inject(0) { |sum, x| sum + x } / size.to_f
  end
  def stddev
    Math.sqrt(self.inject(0) { |sum, x| sum + (x - mean) ** 2 } / size.to_f)
  end
  def stderr
    stddev / Math.sqrt(self.length)
  end
end

def get_capacity
  (`i2cget -y 2 0x55 0x0c w`.to_i(16) * 3570) / $RS / 1000
end

def mean_and_se(array)
  return array.mean, array.stderr
end

def run_measure(title)
  count = 0
  @samples = []
  @monitor = Thread.new do
    last = nil
    while true do
      c = get_capacity
      @samples << last - c if last
      last = c
      sleep($SAMPLE_PERIOD)
    end
  end
  yield
  @monitor.kill
  puts "== #{title} =="
  puts "samples: %s" % @samples.join(", ")
  @samples.map! { |x| x.to_f * 60 * 60 / $SAMPLE_PERIOD }
  puts "drain: %.2f±%.2fmA" % mean_and_se(@samples)
  puts "life: %.2f±%.2fh" % mean_and_se(@samples.map { |x| $CAPACITY / x })
end

sleep(10)

run_measure("baseline") do
  sleep($TEST_PERIOD)
end

@base_dir = "/home/user/MyDocs/test-music/"
@flac_file = @base_dir + "The XX - Islands.flac"
@mp3_file = @base_dir + "Interpol - Who Do You Think.mp3"
@vorbis_file = @base_dir + "Gorillaz - Last Living Soul.ogg"

@commands = [
  {:name => "av flac", :file => @flac_file, :pipe => "flacparse ! avdec"},
  {:name => "flac", :file =>@flac_file, :pipe => "flacdec" },
  {:name => "av mp3", :file =>@mp3_file, :pipe => "mp3parse ! avdec" },
  {:name => "nokiamp3", :file =>@mp3_file, :pipe => "mp3parse ! nokiamp3dec" },
  {:name => "av vorbis", :file =>@vorbis_file, :pipe => "oggdemux ! avdec" },
  {:name => "vorbis", :file =>@vorbis_file, :pipe => "oggdemux ! vorbisdec" },
]

@commands.each do |e|
  run_measure(e[:name]) do
    system("./gst-loop #{$TEST_PERIOD} filesrc location='#{e[:file]}' ! #{e[:pipe]} ! pulsesink")
  end
end