Ubuntu
audacity package

  1. Bug #602934
  2. Comment #46

Comment 46 for bug 602934

Revision history for this message
In , Gale (gale) wrote :

(In reply to comment #33)
> 1) No extreme time differences between m4a and other ffmpeg formats.
> 2) The native exporter is faster than faac
> 3) Faac exported files sound better
> 4) Any file imported with faad gets imported as stereo
> This was all done on the Mac...
 Thanks for your tests, Leland. BTW, switching between different versions of
FFmpeg in Windows is seamless after applying your attached patch - no need for
restart. Excellent! Would still be an ideal "sometime" to have it picked up at
once when installed in the expected place while Audacity is open.

Interesting about 2). I'll see if I find that on my Linux netbook. Given how
slow native exports are for me, how long will faac exports take? Even if 2) is
generally true, I don't think it outweighs 3).

Your speed difference using faac between M4A and other exports is nearly 3x.
I've tested exporting via "M4A files" on Windows 7 x64 desktop using faac/0.6.1
from a copied in 4 minute WAV, then repeated for the same WAV read directly.
WMA, FLAC and OGG take about 40 seconds. AC3 takes about 20 seconds. M4A takes
about 70 seconds. WAV takes about 12 seconds. No significant differences if
source was copied in or not.

1) could still be an issue on slower machines. But here are more tests,
exporting a generated 4 minutes mono tone to M4A:

Win 7 x64 desktop/0.6.1/faac:
"M4A files" - 35 seconds
(external program) - 100 seconds

Ubuntu 10.10 netbook/0.6/native
"M4A files" - 120 seconds
(external program) - 30 seconds

By comparison here are exports to MP3:

Win 7 x64 desktop:
"MP3 files" - 20 seconds
(external program - lame 3.98.4 ) - 100 seconds

Ubuntu 10.10 netbook:
"MP3 files" - 25 seconds
(external program - lame 3.98.4 ) - 25 seconds

All results are repeatable give or take a few seconds.

Those differences between Audacity CLI and GUI for M4A and MP3 on Windows, and
in the other direction on Ubuntu between Audacity CLI and GUI for M4A don't
look "expected" or "reasonable" to me?

I don't think we can do anything about 4) - importing mono as stereo?