logarithmic audio display, fixes #28

1 files changed, 44 insertions, 18 deletions

diff --git a/voctogui/lib/audioleveldisplay.py b/voctogui/lib/audioleveldisplay.py
index f74c3f5..5aaf088 100644
--- a/voctogui/lib/audioleveldisplay.py
+++ b/voctogui/lib/audioleveldisplay.py
@@ -1,4 +1,4 @@
-import logging
+import logging, math
 from gi.repository import Gst, Gtk
 
 class AudioLevelDisplay(object):
@@ -10,6 +10,8 @@ class AudioLevelDisplay(object):
 		self.drawing_area = drawing_area
 
 		self.levelrms = []
+		self.levelpeak = []
+		self.leveldecay = []
 		self.drawing_area.connect('draw', self.on_draw)
 
 	def on_draw(self, widget, cr):
@@ -20,32 +22,56 @@ class AudioLevelDisplay(object):
 
 		width = self.drawing_area.get_allocated_width()
 		height = self.drawing_area.get_allocated_height()
+		margin = 2 # px
 
-		strip_width = int(width / 2)
-		#self.log.debug('width: %u, strip_width: %u', width, strip_width)
+		channel_width = int((width - (margin * (channels - 1))) / channels)
+		# self.log.debug(
+		# 	'width: %upx filled with %u channels of each %upx '
+		# 	'and %ux margin of %upx',
+		# 	width, channels, channel_width, channels-1, margin)
 
-		cr.set_line_width(strip_width)
+		rms_px   = [ self.normalize_db(db) * height for db in self.levelrms ]
+		peak_px  = [ self.normalize_db(db) * height for db in self.levelpeak ]
+		decay_px = [ self.normalize_db(db) * height for db in self.leveldecay ]
 
-		maxdb = -75
+		cr.set_line_width(channel_width)
+		for y in range(0, height):
+			pct = y / height
 
-		for idx, level in enumerate(self.levelrms):
-			level = level / maxdb
+			for channel in range(0, channels):
+				x = (channel * channel_width) + (channel * margin)
 
-			x = idx * strip_width + strip_width/2
-			#self.log.debug('x: %u', x)
+				bright = 0.25
+				if y < rms_px[channel]:
+					bright = 1
+				# elif abs(y - peak_px[channel]) < 3:
+				# 	bright = 1.5
+				elif y < decay_px[channel]:
+					bright = 0.75
 
-			cr.move_to(x, height)
-			cr.line_to(x, height * level)
+				cr.set_source_rgb(pct * bright, (1-pct) * bright, 0 * bright)
 
-			if idx % 2 == 0:
-				cr.set_source_rgb(1, 0, 0)
-			else:
-				cr.set_source_rgb(0, 1, 0)
-
-			cr.stroke()
+				cr.move_to(x, height-y)
+				cr.line_to(x + channel_width, height-y)
+				cr.stroke()
 
 		return True
 
-	def level_callback(self, peaks, rms):
+	def normalize_db(self, db):
+		# -60db -> 1.00 (very quiet)
+		# -30db -> 0.75
+		# -15db -> 0.50
+		#  -5db -> 0.25
+		#  -0db -> 0.00 (very loud)
+		logscale = math.log10(-0.15* (db) +1)
+		normalized = 1 - self.clamp(logscale, 0, 1)
+		return normalized
+
+	def clamp(self, value, min_value, max_value):
+		return max(min(value, max_value), min_value)
+
+	def level_callback(self, rms, peak, decay):
 		self.levelrms = rms
+		self.levelpeak = peak
+		self.leveldecay = decay
 		self.drawing_area.queue_draw()