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-rw-r--r--voctogui/lib/audioleveldisplay.py46
1 files changed, 37 insertions, 9 deletions
diff --git a/voctogui/lib/audioleveldisplay.py b/voctogui/lib/audioleveldisplay.py
index 1d91d35..1a4be14 100644
--- a/voctogui/lib/audioleveldisplay.py
+++ b/voctogui/lib/audioleveldisplay.py
@@ -12,9 +12,12 @@ class AudioLevelDisplay(object):
self.levelrms = []
self.levelpeak = []
self.leveldecay = []
+
+ # register on_draw handler
self.drawing_area.connect('draw', self.on_draw)
def on_draw(self, widget, cr):
+ # number of audio-channels
channels = len(self.levelrms)
if channels == 0:
@@ -22,44 +25,71 @@ class AudioLevelDisplay(object):
width = self.drawing_area.get_allocated_width()
height = self.drawing_area.get_allocated_height()
- margin = 2 # px
- channel_width = int((width - (margin * (channels - 1))) / channels)
+ # space between the channels in px
+ margin = 2
+
+ # 1 channel -> 0 margins, 2 channels -> 1 margin, 3 channels…
+ 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)
+ # normalize db-value to 0…1 and multiply with the height
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 ]
- cr.set_line_width(channel_width)
+ # set the line-width >1, to get a nice overlap
+ cr.set_line_width(2)
+
+ # iterate over all pixels
for y in range(0, height):
- pct = self.clamp(((y / height) - 0.6) / 0.42, 0, 1)
+
+ # calculate our place in the color-gradient, clamp to 0…1
+ # 0 -> green, 0.5 -> yellow, 1 -> red
+ color = self.clamp(((y / height) - 0.6) / 0.42)
for channel in range(0, channels):
+ # start-coordinate for this channel
x = (channel * channel_width) + (channel * margin)
+ # calculate the brightness based on whether this line is in the
+ # active region
+
+ # default to 0.25, dark
bright = 0.25
if int(y - decay_px[channel]) in range(0, 2):
+ # decay marker, 2px wide, extra bright
bright = 1.5
elif y < rms_px[channel]:
+ # rms bar, full bright
bright = 1
elif y < peak_px[channel]:
+ # peak bar, a little darker
bright = 0.75
- cr.set_source_rgb(pct * bright, (1-pct) * bright * 0.75, 0 * bright)
+ # set the color with a little reduced green
+ cr.set_source_rgb(
+ color * bright,
+ (1-color) * bright * 0.75,
+ 0
+ )
+ # draw the marker
cr.move_to(x, height-y)
cr.line_to(x + channel_width, height-y)
cr.stroke()
+ # draw a black line for the margin
cr.set_source_rgb(0,0,0)
cr.move_to(x + channel_width, height-y)
cr.line_to(x + channel_width + margin, height-y)
cr.stroke()
+ # draw db text-markers
cr.set_source_rgb(1, 1, 1)
for db in [-40, -20, -10, -5, -4, -3, -2, -1]:
text = str(db)
@@ -70,7 +100,6 @@ class AudioLevelDisplay(object):
cr.move_to((width-textwidth) / 2, height - y - textheight)
cr.show_text(text)
-
return True
def normalize_db(self, db):
@@ -80,10 +109,9 @@ class AudioLevelDisplay(object):
# -5db -> 0.25
# -0db -> 0.00 (very loud)
logscale = 1 - math.log10(-0.15 * db + 1)
- normalized = self.clamp(logscale, 0, 1)
- return normalized
+ return self.clamp(logscale)
- def clamp(self, value, min_value, max_value):
+ def clamp(self, value, min_value=0, max_value=1):
return max(min(value, max_value), min_value)
def level_callback(self, rms, peak, decay):