alexhemy / audacity

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AIFF files created by Audacity from recorded or generated data import intermittently (but at times very frequently) as noise - files play fine in other software. #21

Open GoogleCodeExporter opened 9 years ago

GoogleCodeExporter commented 9 years ago
* GA: Much of the time, 1.3.7 or later on Windows cannot be relied on to
import files exported with the explicit "AIFF (Apple) signed 16 bit PCM"
filter. Appears to affect exports from recorded data (at any Defauit Sample
Rate), or from tones generated at 24-bit. Same problem occurs with the AIFF
24-bit option accessed with "Options" button, but not apparently the
comparable 16-bit option. Export Multiple seems affected the same way as
regular export. Tested at 44100 Hz, reading directly. On Mac, a user 22
March 09 reports 1.3.7 "suddenly" producing noise when importing AIFF files
where it did not before in many similar imports - user changed default
sample format to 24-bit at about the same time. More details here.

 * LL: Gale, have you been able to find a pattern to recreate this? I've
tried numerous variations on OSX and Windows and it always seems to import ok.

 * GA: Are you using a release build? In ANSI Release from HEAD, I created
a chirp tone in 24-bit quality, recorded it using stereo mix then exported
only the recorded track using the explicit (no options available) AIFF
(Apple) signed 16-bit PCM choice. I changed Quality to 32-bit, closed the
tracks and repeated the generation, record and export. I am not getting
noise on importing the files back into Audacity but what I can replicate is
that about half the time the files will crash both HEAD and 1.3.7 Unicode
Release; if they don't crash they import properly. So behaviour compared to
when I last tested is not the same. I have tried importing with the "All
supported files" and "FFmpeg-compatible files" filter and the problem is
identical. In 1.2.6 I can import these files dozens of times without problem. 

Original issue reported on code.google.com by James.K....@gmail.com on 25 Sep 2009 at 6:12

GoogleCodeExporter commented 9 years ago

Original comment by James.K....@gmail.com on 25 Sep 2009 at 6:12

GoogleCodeExporter commented 9 years ago
I'd expect bugs around using 24-bit as the native sample format in Audacity. 
They
have been there since the dawn of time (I remember reproducing one in audacity 
1.2.3
or so, which didn't affect either 16-bit int or 32-bit float), and include 
various
forms of byte swap and failure to de-interleave the "two samples in 3 16-bit 
words"
encoding which is possible (although not universal) in 24-bit files.

I would be tempted to put a health warning on 24-bit native mode as "may be 
broken,
will take patches but we aren't working on it" and then any report which comes 
from
someone running in 24-bit data format gets ignored. Do we have any definite 
reports
of this from Audacity in default configuration (which will give identical 
results to
24-bit mode, but frequently quicker)?

Original comment by RichardAsh1981 on 28 Sep 2009 at 8:11