HydrogenAudio

Lossy Audio Compression => AAC => AAC - General => Topic started by: Destroid on 2013-07-04 22:54:01

Title: Undetermined M4A tag differences between encoders
Post by: Destroid on 2013-07-04 22:54:01
Like the topic says, I get slightly different tags between the two encoders, which both used the same front-end (FB2K) during conversions.

Normally this is a non-issue. However, I would like to know what miniscule difference exists since my portable reads Artist/Album/etc. from the files created by Nero. With the FhgAAC files it reads none at all. A short test later with two encodes using the same source file and conversion method confirmed this result.

The latest version of MP3Tag showed only a difference in the 'Codec' field: "MPEG4-AAC (Nero AAC encoder / 1.5.1.0)" versus "MPEG4-AAC" the latter being FhgAAC. FB2K 'Properties' revealed an extra field <ENCODER> under 'Other' (not under 'General' tag). I tried 'Remove all fields' from the FhgAAC file and copy+pasted the fields from the Nero file, and that didn't solve anything either.

If someone does know what this difference is maybe they could also tell me if I can alter the existing tags for my finicky player as opposed to re-encoding with Nero. Thanks in advance!

edit: typos
Title: Undetermined M4A tag differences between encoders
Post by: eahm on 2013-07-04 23:05:50
Are you also referring to this? http://www.hydrogenaudio.org/forums/index....st&p=809211 (http://www.hydrogenaudio.org/forums/index.php?s=&showtopic=85135&view=findpost&p=809211)
Title: Undetermined M4A tag differences between encoders
Post by: Destroid on 2013-07-04 23:21:27
 I don't have high-speed connection right now, so I am wondering if there was something smaller and less deprecated to try.
Title: Undetermined M4A tag differences between encoders
Post by: Destroid on 2013-07-05 01:06:39
Are you also referring to this? http://www.hydrogenaudio.org/forums/index....st&p=809211 (http://www.hydrogenaudio.org/forums/index.php?s=&showtopic=85135&view=findpost&p=809211)
No.  I mentioned the encoder field merely in regards to the only known difference.

The bad news is MP4Tags didn't help. The good news is that it mentioned something called iTunes-compatible tags. So obviously I tried an encode using QAAC (with lib 7.9.7.9) and that file's tag is recognized by my player. Still, I can't help but continue to figure out what difference exists with the FhgEnc tags.
Title: Undetermined M4A tag differences between encoders
Post by: nu774 on 2013-07-05 02:14:47
From what I can see,
neroaacenc writes moov.udta.ndrm before moov.udta.meta box under which iTunes style metadata goes.
On the other hand, winamp encoder writes moov.udta.hnti box (http://www.hydrogenaudio.org/forums/index....showtopic=90901 (http://www.hydrogenaudio.org/forums/index.php?showtopic=90901))  before moov.udta.meta box.
iTunes does not write both of them, and meta box comes first under moov.udta.

Maybe your player accepts ndrm but refuses hnti. Try the following:
Code: [Select]
AtomicParseley foo.m4a --manualAtomRemove moov.udta.hnti


If it doesn't work, you can remux it using cafmux (https://sites.google.com/site/qaacpage/cabinet).
Code: [Select]
cafmux foo.m4a bar.m4a

It doesn't preserve tags, but at least gapless information (iTunSMPB) is preserved and remuxed using Apple CoreAudioToolbox.
Title: Undetermined M4A tag differences between encoders
Post by: Destroid on 2013-07-07 02:04:56
Maybe your player accepts ndrm but refuses hnti. Try the following:
Code: [Select]
AtomicParseley foo.m4a --manualAtomRemove moov.udta.hnti
That worked. I am pretty sure the blame for this lies within my player but having this workaround makes it a little more bearable.

Thank you very much!