m4a FDK (AAC) @ 256kbps CBR - 96khz??

[theSC00BZ]

Recently got a new DAP that supports higher bitrates, so I wanted to convert my 192khz stuff to 96khz with above codec.

From what I understand, AAC should support a sample rate up to 96khz, but when using music converter it appears to work, but the output file has corrupted tag information and the file size ends up being the same as trying 88khz. I tried at 48khz which works fine, but the file size is only fractionally smaller than the 96 one. Should this codec support anything above 48khz?

[garym]

Re: m4a FDK (AAC) @ 256kbps CBR - 96khz??

Recently got a new DAP that supports higher bitrates, so I wanted to convert my 192khz stuff to 96khz with above codec.

From what I understand, AAC should support a sample rate up to 96khz, but when using music converter it appears to work, but the output file has corrupted tag information and the file size ends up being the same as trying 88khz. I tried at 48khz which works fine, but the file size is only fractionally smaller than the 96 one. Should this codec support anything above 48khz?

I can't answer your question, but I'm hoping you do realize that converting a lossy file (like an AAC or MP3) to a high-res file can be done *but it adds nothing to the file in terms of sound quality*. All you end up with is a very, very large file that has exactly the same audio data as the lossy file you started with.
edit: and if you're converting lossy to lossy (m4a to m4a), it is even worse as every lossy conversion is another generation adding its own "losses" (unlike a lossless to lossless conversion which is Ok (e.g, FLAC to FLAC, FLAC to ALAC, etc.)

[theSC00BZ]

Re: m4a FDK (AAC) @ 256kbps CBR - 96khz??

Sorry if there was some confusion... I have 24/192 flac files. I previously converted them to 16/48 aac, but with a better DAP, I can now convert from my original 24/192 flac to 24/96 aac instead ....but the encoder doesn't seem to like the 96 part. I don't want to lose quality, I'm trying to improve it

Just for clarity... Original 24/192 flac for home listening. Wanting to convert to 24/96 for my DAP. I'd love to keep 24/192 for my DAP, but they don't make sd cards big enough yet :sad:

[garym]

Re: m4a FDK (AAC) @ 256kbps CBR - 96khz??

Sorry if there was some confusion... I have 24/192 flac files. I previously converted them to 16/48 aac, but with a better DAP, I can now convert from my original 24/192 flac to 24/96 aac instead ....but the encoder doesn't seem to like the 96 part. I don't want to lose quality, I'm trying to improve it

Just for clarity... Original 24/192 flac for home listening. Wanting to convert to 24/96 for my DAP. I'd love to keep 24/192 for my DAP, but they don't make sd cards big enough yet :sad:

aha. Now I understand. Hopefully Spoon can assist.

[Spoon]

Re: m4a FDK (AAC) @ 256kbps CBR - 96khz??

AAC might support that frequency, however FDK might not. Remember that it is the codec which has to decide what is best, for example if you encode:

44KHz to 128Kbps

or

88KHz to 128 Kbps, this latter will be the equivalent of a 44KHz 64 kbps file, so the encoder might correctly decide to drop the 88KHz automatically to 44KHz to preserve audio quality, because I can tell you now 44KHz 128Kbps sounds better than any 88KHz 128Kbps file.

[theSC00BZ]

Re: m4a FDK (AAC) @ 256kbps CBR - 96khz??

Thanks for the quick reply... I was assuming it's an error as the tag information becomes corrupted (missing most meta data) when trying to convert to 96, but not 48.

How's the old nero aac doing? Is it still supported by R15? (I could give that a try later)

(Also see your point about the sample and bit rate combination. Didn't think that far ahead before)

[theSC00BZ]

Re: m4a FDK (AAC) @ 256kbps CBR - 96khz??

http://wiki.hydrogenaud.io/index.php?title=Fraunhofer_FDK_AAC*Sample_Rates

FDK library officially supports sample rates for input of 8000, 11025, 12000, 16000, 22050, 24000, 32000, 44100, 48000, 64000, 88200, and 96000 Hz

According to the wiki, 96khz is supported - but later in the page it is not in the recommended section. Maybe 512kbps for 96khz is a better option? Does anyone have any recommended (lossy) codec for good quality @ 96khz? (2 channel, 24bit depth, up to 512kbps)

Something still going on with the tagging though, as 96khz sample rate as a target doesn't copy the tags.

[Spoon]

Re: m4a FDK (AAC) @ 256kbps CBR - 96khz??

I can confirm there is an issue encoding to high sample rates, the issue seems to affect dBpoweramp popup info for aac files with 96KHz, the file is encoded correctly as foobar can read the tags and properties.

[theSC00BZ]

Re: m4a FDK (AAC) @ 256kbps CBR - 96khz??

[COLOR="*FF0000"]@Mods[/COLOR]

Would any mod care to explain why my follow up post siting:

- A wiki page and technical info over the FDK encoder
- Explaining a problem with missing tags when converting with FDK
- Asking for any recommended alternatives to FDK

...required moderator approval, and then apparently rejected?

At the risk of sounding like an old-timer; that's rather rude and bad form. Also considering the fact I've been a paying customer for the last 'x' years. Hopefully this one makes it through.

[Spoon]

Re: m4a FDK (AAC) @ 256kbps CBR - 96khz??

It was not rejected, just waiting for approval.