I just tested --underlap 2 vs --underlap 8, --underlap 8 is always better & ABXable.
foo_abx 1.3.3 report
foobar2000 v0.9.6.4
2009/04/17 11:26:04
File A: C:\00- Therion (Artefact+Context) V1.1.3j -Q 0 --underlap 2.lossy.flac
File B: C:\00- Therion (Artefact+Context) V1.1.3j -Q 0 --underlap 8.lossy.flac
11:26:04 : Test started.
11:26:27 : 01/01 50.0%
11:26:53 : 02/02 25.0%
11:27:15 : 03/03 12.5%
11:27:48 : 04/04 6.3%
11:28:22 : 05/05 3.1%
11:28:44 : 06/06 1.6%
11:29:06 : 07/07 0.8%
11:29:25 : 08/08 0.4%
11:29:27 : Test finished.
----------
Total: 8/8 (0.4%)
foo_abx 1.3.3 report
foobar2000 v0.9.6.4
2009/04/17 11:29:42
File A: C:\01- Abfahrt Hinwil (Artefact Only) V1.1.3j -Q 0 --underlap 2.lossy.flac
File B: C:\01- Abfahrt Hinwil (Artefact Only) V1.1.3j -Q 0 --underlap 8.lossy.flac
11:29:42 : Test started.
11:29:55 : 01/01 50.0%
11:30:05 : 02/02 25.0%
11:30:15 : 03/03 12.5%
11:30:22 : 04/04 6.3%
11:30:31 : 05/05 3.1%
11:30:42 : 06/06 1.6%
11:30:50 : 07/07 0.8%
11:30:58 : 08/08 0.4%
11:30:59 : Test finished.
----------
Total: 8/8 (0.4%)
Then I tested -Q 0 --underlap 2 Vs. -Q 0.5 in order to see if --underlap 2 was better or worse than --underlap 5 (which I previously tested & is near to a 0.5 gain in the scale), first I add some trouble catching a difference but then I catched something & then it was a 100% success so I went up to 20 trials to erease the first failures. It was even easier on Abfahrt Hinwil which was a 8/8 from the start. The conclusion is --underlap 2 is worst than a 0.5 increase in the scale. --underlap is a time greedy parameter but it does improve quality in a very scalable way:
--underlap 2 < --underlap 5 (+0.5 increase in the scale) < --underlap 8, but --underlap 8 is very slow.
foo_abx 1.3.3 report
foobar2000 v0.9.6.4
2009/04/17 11:33:05
File A: C:\11- Lossywav Test\00- Therion (Artefact+Context) V1.1.3j -Q 0 --underlap 2.lossy.flac
File B: C:\11- Lossywav Test\00- Therion (Artefact+Context) V1.1.3j -Q 0.5.lossy.flac
11:33:05 : Test started.
11:33:39 : 00/01 100.0%
11:36:06 : 01/02 75.0%
11:36:27 : 02/03 50.0%
11:37:32 : 02/04 68.8%
11:38:06 : 02/05 81.3%
11:38:56 : 03/06 65.6%
11:39:13 : 04/07 50.0%
11:39:26 : 05/08 36.3%
11:39:37 : 06/09 25.4%
11:39:49 : 07/10 17.2%
11:40:02 : 08/11 11.3%
11:40:14 : 09/12 7.3%
11:40:26 : 10/13 4.6%
11:40:33 : 11/14 2.9%
11:40:47 : 12/15 1.8%
11:41:06 : 13/16 1.1%
11:41:19 : 14/17 0.6%
11:41:34 : 15/18 0.4%
11:42:02 : 16/19 0.2%
11:42:32 : 17/20 0.1%
11:42:37 : Test finished.
----------
Total: 17/20 (0.1%)
foo_abx 1.3.3 report
foobar2000 v0.9.6.4
2009/04/17 11:44:12
File A: C:\01- Abfahrt Hinwil (Artefact Only) V1.1.3j -Q 0 --underlap 2.lossy.flac
File B: C:\01- Abfahrt Hinwil (Artefact Only) V1.1.3j -Q 0.5.lossy.flac
11:44:12 : Test started.
11:44:57 : 01/01 50.0%
11:45:17 : 02/02 25.0%
11:45:37 : 03/03 12.5%
11:45:56 : 04/04 6.3%
11:46:11 : 05/05 3.1%
11:46:29 : 06/06 1.6%
11:46:49 : 07/07 0.8%
11:47:07 : 08/08 0.4%
11:47:09 : Test finished.
----------
Total: 8/8 (0.4%)
I tried too ABX -q 0 --sortspread 3 Vs. -q 0 --sortspread 7, but I failed, it seems --sortspread is not as scalable as --underlap. Unlike --underlap it seems --sortspread is a flat ~0.5 quality increase in the scale that doesn't improve much if you increase the parameter.
It remains to be tested for transparency but IMHO swallowing (-q 1.5 --sortspread 3 --analyses 5) or (-q 2 --sortspread 3 --analyses 5) as the new -portable might be a good start if --underlap is too CPU greedy. (-q 2 --sortspread 3 --analyses 5) is for almost sure already transparent with no drawback ... in fact all that remains to be tested is how far (-q 1.5 --sortspread 3 --analyses 5) is from being transparent. Also what is the min/max for --analyses, I know from --help the default is 2 but is there any logic behind 5 analyses instead of more or less, do you have a preference for --analyses ? Is 5 random ?