Waveform doesn't show for quiet files

[Christian Dannie Storgaard]

When importing (possibly also when recording) sound files that aren't that loud, no waveform is shown on the track.

[Christian Dannie Storgaard (cybolic)]

Test ogg file here

[John Green (john-thegreens)]

Interesting. This file has just a right hand channel. I converted it to mono in audacity and reimported it and the waveform very definitely shows. I think there is a bug in our level measurement if the left channel is missing.

[Luke Tilley (sinisterguy)]

the problem is in Event.py line 475:

if st.get_name() == "level":
 end = st["endtime"] / float(gst.SECOND)
 self.levels.append(DbToFloat(st["peak"][0]))
 self.loadingLength = int(end)

st["peak"] contains 2 values, one for each channel of the audio. We're currently only taking the measurement of the left channel. The only question is how do you properly represent a stereo file in one waveform? I was thinking of just doing the average of the two (which works to fix the problem btw) but i'm not sure if this is the proper method.

[Laszlo Pandy (laszlok)]

It turns out that where there is no audio, the level element gives us negative infinity, and anything added to negative infinity is still negative infinity. Now we check this before adding the values.