Quicktime TVBR vs Nero AAC
Reply #53 – 2011-02-26 01:09:21
/mnt , have you tried this sample with qt aac?beats.tak If not - try to encode it with qaac -V 127 -q2 and listen It looks like quicktime's vbr algoritm problem... The VBR on QuickTime seems to be buggy:foo_abx 1.3.4 report foobar2000 v1.1.4 2011/02/26 00:50:11 File A: C:\Downloads\beats.tak File B: C:\Temp\beats tvbr 127.m4a 00:50:11 : Test started. 00:50:18 : 01/01 50.0% 00:50:21 : 02/02 25.0% 00:50:27 : 03/03 12.5% 00:50:30 : 04/04 6.3% 00:50:34 : 05/05 3.1% 00:50:38 : 06/06 1.6% 00:50:44 : 07/07 0.8% 00:50:49 : 08/08 0.4% 00:50:54 : 09/09 0.2% 00:51:02 : 10/10 0.1% 00:51:07 : 11/11 0.0% 00:51:12 : 12/12 0.0% 00:51:27 : 13/13 0.0% 00:51:29 : 14/14 0.0% 00:51:35 : 15/15 0.0% 00:51:40 : 16/16 0.0% 00:51:51 : Test finished. ---------- Total: 16/16 (0.0%) Very obivious artifacts through out. Going lower to tvbr 90 shows something interesting.foo_abx 1.3.4 report foobar2000 v1.1.4 2011/02/26 00:53:05 File A: C:\Temp\beats tvbr 90.m4a File B: C:\Temp\beats tvbr 127.m4a 00:53:05 : Test started. 00:53:12 : 01/01 50.0% 00:53:16 : 02/02 25.0% 00:53:20 : 03/03 12.5% 00:53:26 : 04/04 6.3% 00:53:29 : 05/05 3.1% 00:53:32 : 06/06 1.6% 00:53:36 : 07/07 0.8% 00:53:41 : 08/08 0.4% 00:53:45 : 09/09 0.2% 00:53:49 : 10/10 0.1% 00:53:53 : 11/11 0.0% 00:53:56 : 12/12 0.0% 00:53:59 : 13/13 0.0% 00:54:03 : 14/14 0.0% 00:54:08 : 15/15 0.0% 00:54:12 : 16/16 0.0% 00:54:16 : Test finished. ---------- Total: 16/16 (0.0%) It sounds fine to me at 90, but at 127 it has horrid pre-echo. Bitrates are similar aswell, the tvbr 90 encode is at 62kbps and the 127 encode is at 65kbps.