HydrogenAudio

Hydrogenaudio Forum => Listening Tests => Topic started by: peskypesky on 2020-06-12 14:49:19

Title: Personal ABX test: Hi-Res Flac vs 128kbs AAC
Post by: peskypesky on 2020-06-12 14:49:19
I compared a 24-192 FLAC with an AAC I made. I used fre:ac audio converter v.1.1.
core audio encoder. LC 128kbps

my results:

foo_abx 2.0.6d report
foobar2000 v1.4.6
2020-06-12 08:33:18

File A: 06 I Thought About You.flac
SHA1: 7bc117ab9a84a326ece0ef797c848e240dc2db77
Gain adjustment: -0.76 dB
File B: 06 - I Thought About You.m4a
SHA1: 81598f68556a571b3a15157499405abca6294f3a
Gain adjustment: -0.75 dB

Output:
DS : Primary Sound Driver
Crossfading: NO

08:33:18 : Test started.
08:37:09 : 00/01
08:38:06 : 01/02
08:38:35 : 02/03
08:39:28 : 02/04
08:40:19 : 03/05
08:41:04 : 03/06
08:42:16 : 03/07
08:43:14 : 04/08
08:43:14 : Test finished.

 ----------
Total: 4/8
p-value: 0.6367 (63.67%)

 -- signature --
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Title: Re: Personal ABX test: Hi-Res Flac vs 128kbs AAC
Post by: lozenge on 2020-06-20 22:35:59
I'm guessing that since FDK_AAC's license restricts it from being distributed as a binary, that the Fre:ac version you're using is encoding with FAAC, which has always been a pretty poor implementation of AAC.... It would be interesting to see if you get the same result with the same track encoded with a better encoder (Apple / Fhg  / FDK-AAC are recommended).
Title: Re: Personal ABX test: Hi-Res Flac vs 128kbs AAC
Post by: kode54 on 2020-06-21 01:16:21
Fre:ac supports FDK-AAC, but you have to specifically select it as the encoder. Many distributions do provide FDK-AAC binaries, and a package like this, as built by the distribution, or as built by the user with FDK-AAC installed (including any development headers, depending on the distribution), should support FDK-AAC.

Just be sure to select it correctly. You want the encoder option "Fraunhofer FDK AAC Encoder", or configure that from the multi-encoder configuration if you use that. It appears to default to 64 kbps per channel, LC AAC, in MP4 container, with a .m4a extension.

EDIT: I didn't read the OP properly before replying. You appear to be using the macOS version. The Core Audio AAC encoder will be using Apple's encoder, which is actually likely the best encoder available. I would suggest using higher than 64kbps per channel, or 128kbps for stereo. If you want to use what Apple uses for their online store, you'll need to select 128kbps per channel / 256kbps stereo, not sure if you need to set it to CVBR?
Title: Re: Personal ABX test: Hi-Res Flac vs 128kbs AAC
Post by: lozenge on 2020-06-24 18:32:32
... Many distributions do provide FDK-AAC binaries ...

Good news, thanks for the correction.
Title: Re: Personal ABX test: Hi-Res Flac vs 128kbs AAC
Post by: kode54 on 2020-06-25 08:10:04
I may have jumped the gun. I only assumed so from how Arch does, but Arch is kind of fringe. I wonder if Debian or Ubuntu or Fedora do?
Title: Re: Personal ABX test: Hi-Res Flac vs 128kbs AAC
Post by: magicgoose on 2020-06-25 14:00:05
I may have jumped the gun. I only assumed so from how Arch does, but Arch is kind of fringe. I wonder if Debian or Ubuntu or Fedora do?
Manjaro also uses Arch packages and it's kind of big.
Title: Re: Personal ABX test: Hi-Res Flac vs 128kbs AAC
Post by: lozenge on 2020-06-26 01:13:23
I may have jumped the gun. I only assumed so from how Arch does, but Arch is kind of fringe. I wonder if Debian or Ubuntu or Fedora do?

Debian does (in non-free since at least stretch / old-stable) so Ubuntu and other derivatives will too. Can't believe I missed it for so long!

Ive never heard of the site pkgs.org but a quick search shows they have packages for Fedora/RH/Centos as well as Slackware,, OpenSUSE & "PCLinuxOS" (I trust Debian, but I'd probably continue to compile from source if that was the only other option).