Nero Digital m4a encoder (19/07/06)

[Sojo]

Hi,
I'm new to the forum (not codecs) so maybe the answer is already known...but I have been using the new Nero Digital m4a encoder just fine but want to force to Low Complexity as my iPod Nano will not "see" the HE content.

I tick the box in the options for the encoder but running the mouse over the encoded file the properties show AAC type - High Efficiency (SBR).

Although the playback on the ipod sounds ok I was wondering if it was just a bug or if the file really was HE regardless of the setting. I know the encoder defaults to HE but the checkbox seems to do nothing if this is the case.

Any help much appreciated...ta!

Sojo

[Deano]

Re: Nero Digital m4a encoder (19/07/06)

I would imagine it is a possible bug in dBpowerAMP's routines. My friend downloaded a song from iTunes and dBpowerAMP claimed it to be HE-AAC (which is not true, they wouldn't work on iPods if they were).

What bitrate/quality setting did you put the codec in? What is the bitrate read out when you hover over the file in dBpowerAMP?

When I personally tested this codec, I never got this problem (or at least on files where I was expecting to get a LC-AAC file). It doesn't mean that dBpowerAMP doesn't get confused at lower bitrates.

[Sojo]

Re: Nero Digital m4a encoder (19/07/06)

Thanks for the info...

I encoded the wav file to Quality .55 (~200kbps) and the properties show a bitrate of 140 kbps presumably because it is a variable bitrate.

This ia quite a high bitrate so shouldn't have been a problem.

[Deano]

Re: Nero Digital m4a encoder (19/07/06)

A bitrate setting that high should definately not have produced a HE-AAC file to my knowledge. I believe the threshold for HE-AAC is around 96kbps as I recall from reading HydrogenAudio.

Have you tried without the "force LC-AAC" ticked? I know for sure in my tests, at 0.55 I got an LC-AAC file (this was without the "force" button ticked).

Just for your info, here were my results.

[Sojo]

Re: Nero Digital m4a encoder (19/07/06)

I have encoded at ALL bitrates and found no mater if I force the LC or just leave it unchecked...ALL the properties show HE. Plays fine on iPod Nano.

Also, properties show Tool: Nero AAC/May 26 2006.

Must be a bug as you suggested..happy to continue using until I can find a problem after I have done more tests...thanks.

[LtData]

Re: Nero Digital m4a encoder (19/07/06)

What are you using to see if it is HE or not?

[REVLIK]

Re: Nero Digital m4a encoder (19/07/06)

Wow, I'm sorry. I searched for over an hour looking for an answer to my problem, and this thread is exactly what I've been trying to figure out.

I've been using the pop-up file info and Windows Explorer properties tab that came with dB to see if a m4a file is LC or HE. Each file I've encoded, regardless of ticking the "Force LC" box , show up has HE in the dB WEtab/pop-up. iTunes will say that the same file is LC.

While doing some tests, I noticed that iTunes will encode smaller files than dMC will at the same quality. This is what makes me think that they're being encoded in HE.

[Deano]

Re: Nero Digital m4a encoder (19/07/06)

The iTunes encoder will not produce the same output as the Nero encoder, even at similar bitrates the filesizes are likely to be at least a little different due to the differences in the way the encoder works and the way they implement VBR. If iTunes is saying that the files produced from dBpowerAMP are LC, I am liable to believe this assumption.

Maybe you should check in other programs and see what they say.

Files of higher bitrate should *not* be High Effeciency (ie, contain SBR) simply because it is *not* required on these files. The Nero encoder will only use High Effeciency on low bitrate encoded files, it would not make sense on higher bitrate files.

I still believe this is a bug with the dBpowerAMP detection. On AAC files encoded on my computer, it seemed to work fine. This does not, however, explain the previously mentioned troubles when a friend sent me an iTunes encoded file.

[REVLIK]

Re: Nero Digital m4a encoder (19/07/06)

I guess it is a bug. dB labels all files as SBR and iTunes labels everything as LC. After checking with foobar2000, I could accuratly see what files are LC and what files are SBR.

dMC is encoding everything right (I used foobar to verify this). I only thought dMC was making all files HE because every file I encoded came out bigger than when iTunes encoded it.

I could have saved myself a lot of grief last night if I had only thought to check with foobar.