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[SLUG] White noise at the end of a WAV file that only Audacity can't see
- To: slug <slug@xxxxxxxxxxx>
- Subject: [SLUG] White noise at the end of a WAV file that only Audacity can't see
- From: Mary Gardiner <mary@xxxxxxxxxxxx>
- Date: Tue, 21 Jul 2009 10:00:10 +1000
- User-agent: Mutt/1.5.18 (2008-05-17)
I am trying to re-encode some music files from Apple Lossless to FLAC
and there is a very short burst of white noise at the end of the file
that every music player *except* Audacity can see.
Here's what I am doing.
1. Convert the ALAC music files to WAV (I was originally going straight
to FLAC, but tried to cut some steps out in order to figure out which
step in the chain was producing the white noise).
Either of these tools produce the same effect:
alac-decoder -f output.wav input.m4a
ffmpeg -i input.m4a output.wav
2. Listen to the WAV files using any of the following tools:
All of them render about 1/4 second or so of white noise at the very
end of the playback. Further, this is preserved by "flac" when I
convert the WAV file to FLAC.
3. Think "oh well, I guess I can edit the white noise off with
Open WAV file in Audacity, discover that the white noise is not there
in Audacity (not in the waveform, not present when I use Audacity itself
to play it back)
4. Think "oh well, it's the least automatable setup ever, but if
Audacity doesn't render the white noise, I can at least use it to
export to FLAC!"
Do so, and discover that the resulting FLAC files still have the
white noise at the end when played in totem/Squeezecenter/Rhythmbox.
I've also had a friend with Apple hardware (an iPod) play the original
ALAC files and he reports that they do not contain a burst of white
noise at the end.
So I am out of ideas: does anyone know what the white noise is, why
Audacity can't see it and thus let me edit it off but still renders it,
or any tools that will allow me to produce FLAC files without a very
annoying burst of static at the end?
 I have Apple Lossless files because that's the only lossless format
that The Dandy Warhols are selling The Dandy Warhols Are Sound in.