AP 2.7.5 and AAC coding issue?

GregDunn · Post by **GregDunn** » Wed Apr 01, 2020 9:19 pm

Running OS X 10.13.6, latest update.

When exporting an edited AIFF file as an m4a/AAC file at 192 kbps, I notice the two following issues:

1) iTunes/QT shows the bit rate as 162 kbps.

2) There is an odd modulation, somewhat like an echo, superimposed on the audio when it is played back by an application. This issue is not present in the original 16 bit AIFF file. It sounds somewhat like the artifacts you would get from encoding at a very low bit rate such as 64 kbps.

Importing the AIFF file directly into iTunes and then converting it to AAC resulted in a file with no noticeable issues. So perhaps there is a setting I have overlooked in AP?

Reading the forum, I saw that some people had issues when running Default Folder. I disabled it for AP but it made no difference in the file metadata.

Post by **Martin Hairer** » Thu Apr 02, 2020 9:14 am

Dear Greg, could you please send me a link to an example of files displaying this issue (both the original AIFF file and the resulting m4a file) as well as a screenshot of the settings used to create the m4a file? Thanks a lot! Regards,

Martin

--
HairerSoft
http://www.hairersoft.com/

GregDunn · Post by **GregDunn** » Thu Apr 02, 2020 2:13 pm

I'll be sending it in a few minutes! Many thanks.

FYI, I observed that when I play the AP-exported AAC file via QuickTime Player, the audio has the aforementioned issues; however, if I import the same AAC file back into AP, it plays properly. It may be that the header info is not being interpreted the same way by QuickTime?

Post by **Martin Hairer** » Thu Apr 02, 2020 7:05 pm

Thanks. That's very strange: on my system, both files sound indistinguishable whether I play them back in QuickTime Player or with the Finder's Quick Look. That's on macOS 10.15, but just to be sure I also tried with macOS 10.13 (using Parallels) and obtained the same results.

So the files definitely appear to be fine. What happens if you create a clean user account on your computer and try playing it there? Regards,

Martin

--
HairerSoft
http://www.hairersoft.com/

GregDunn · Post by **GregDunn** » Tue Apr 14, 2020 4:19 pm

Sorry about the delay - I will try this on a new account as well as my two spare machines and report back with my findings.