Hi
I encounter 2 problems, first one:
there is a lot of clipping in vorbis from -q5 to -q10, You can see it on screenshots (in all screenshots first wave is source wav, second vorbis -q8 encoded with aoTuV 5.61).
Encoding to vorbis files that are very close to clipping gives output file with actual clipping, is there maby a way to tell encoder that if wave goes to close to clipping, have higher bitrate to avoid it.
I know You can use ReplayGain to avoid clipping, but it`s not default option, i`v made package of source and test files from -q5 to -q8 (aoTuV 5.61), the *.ogg files have calculated peak value in tags and You can simply play them in foobar2000, put volume a bit up and see how much of clipping is inside that files, for comparison You can use source file or aply ReplayGain - avoid clipping accordin to peak by track.
To clean up someone else's TOS#8 mess...
OK, the udial.wav sample provided is incredibly ABXable and annoying at -q5 with the Linux static gcc4 oggenc-aotuv b5.61 linked from the wiki, it shows a weird distortion that may or may not be (EDIT: Upon further review, it apparently is) related to clipping.
foo_abx 1.3.1 report
foobar2000 v0.9.5.1
2009/01/08 23:22:53
File A: D:\clipping\udial.wav
File B: D:\clipping\udial-q5.ogg
23:22:53 : Test started.
23:24:06 : 01/01 50.0%
23:25:16 : 02/02 25.0%
23:25:34 : 03/03 12.5%
23:25:43 : 04/04 6.3%
23:25:53 : 05/05 3.1%
23:26:04 : 06/06 1.6%
23:26:23 : 07/07 0.8%
23:26:59 : 08/08 0.4%
23:27:04 : Test finished.
It's easily ABXable at -q6 with the same distortion, only less of it.
foo_abx 1.3.1 report
foobar2000 v0.9.5.1
2009/01/08 23:27:30
File A: D:\clipping\udial.wav
File B: D:\clipping\udial-q6.ogg
23:27:30 : Test started.
23:27:49 : 01/01 50.0%
23:28:02 : 02/02 25.0%
23:28:14 : 03/03 12.5%
23:28:25 : 04/04 6.3%
23:29:31 : 05/05 3.1%
23:29:54 : 06/06 1.6%
23:30:03 : 07/07 0.8%
23:30:15 : 08/08 0.4%
23:30:18 : Test finished.
----------
Total: 8/8 (0.4%)
At -q7, it's still fairly ABXable though the distortion isn't as annoying. I could probably live with it.
foo_abx 1.3.1 report
foobar2000 v0.9.5.1
2009/01/08 23:31:54
File A: D:\clipping\udial.wav
File B: D:\clipping\udial-q7.ogg
23:31:54 : Test started.
23:32:19 : 01/01 50.0%
23:32:25 : 02/02 25.0%
23:32:34 : 03/03 12.5%
23:32:50 : 04/04 6.3%
23:32:56 : 05/05 3.1%
23:33:06 : 06/06 1.6%
23:33:13 : 07/07 0.8%
23:33:23 : 08/08 0.4%
23:33:24 : Test finished.
----------
Total: 8/8 (0.4%)
At q8, it's still easly ABXable
foo_abx 1.3.1 report
foobar2000 v0.9.5.1
2009/01/08 23:34:46
File A: D:\clipping\udial.wav
File B: D:\clipping\udial-q8.ogg
23:34:46 : Test started.
23:34:58 : 01/01 50.0%
23:35:07 : 02/02 25.0%
23:36:33 : 03/03 12.5%
23:36:39 : 04/04 6.3%
23:36:46 : 05/05 3.1%
23:36:54 : 06/06 1.6%
23:36:59 : 07/07 0.8%
23:37:08 : 08/08 0.4%
23:37:11 : Test finished.
----------
Total: 8/8 (0.4%)
Still fairly ABXable at -q9.
foo_abx 1.3.1 report
foobar2000 v0.9.5.1
2009/01/08 23:38:01
File A: D:\clipping\udial.wav
File B: D:\clipping\udial-q9.ogg
23:38:01 : Test started.
23:38:23 : 01/01 50.0%
23:38:29 : 02/02 25.0%
23:38:44 : 03/03 12.5%
23:38:52 : 04/04 6.3%
23:39:00 : 05/05 3.1%
23:39:09 : 06/06 1.6%
23:39:19 : 07/07 0.8%
23:39:24 : 08/08 0.4%
23:39:26 : Test finished.
----------
Total: 8/8 (0.4%)
At -q10, it may actually be worse than -q9.
foo_abx 1.3.1 report
foobar2000 v0.9.5.1
2009/01/08 23:40:20
File A: D:\clipping\udial.wav
File B: D:\clipping\udial-q10.ogg
23:40:20 : Test started.
23:41:25 : 01/01 50.0%
23:41:32 : 02/02 25.0%
23:41:44 : 03/03 12.5%
23:41:54 : 04/04 6.3%
23:42:08 : 05/05 3.1%
23:42:21 : 06/06 1.6%
23:42:30 : 07/07 0.8%
23:42:37 : 08/08 0.4%
23:42:40 : Test finished.
----------
Total: 8/8 (0.4%)
All of this was done with replaygain off.
With replaygain on in the abx tester, I don't think I can ABX it, but there's a strange noise (sounds kinda like an alien ray gun in some cheesy low-budget sci-fi film) on both the lossless and lossy copies (WINE bug? foobar abx plugin and diskwrriter plugin applying track gain while completely disregarding the maximum gain that can be applied without causing clipping?).