Could you confirm that ALAC doesn't play sample rate of 96 kHz?

scrutinizer82 wrote:

Hi,

Could you confirm for me that ALAC doesn't play sample rate of 96 kHz? Because my codecs converter, regardless of what sampling I set up gives me 44.1 KHz in ALAC.

Thanks

Hello Scrutinizer,

Don't know if you are still around, but I just noticed that this question has been sitting unanswered for over 3 months....

Yes, ALAC can play at 96 kHz. There may be a limitation in the converter that you used. If you do the conversion with iTunes, starting with a WAV file at 96 kHz, it will produce an ALAC file with sample rate of 96 kHz.

Also note that you should set your iTunes playback preferences accordingly, as shown below.

Hello Scrutinizer,

The thing is I'm a Mac user and the settings wouldn't allow me to tweak them as I don't have such options (Play Audio Sound, Bitrate For Audio Playback, Bits Per Sample For Audio) at all (iTunes 11.4 for Mac).

I forget when those new Playback preferences were introduced, but they are definitely there in iTunes 12. (It is funny that they refer to the sample rate as the "Bitrate for Audio Playback," which is simply incorrect!)

For conversion I use XLD which gives quite good options and every time I set bitrate to 192 kHz, I get 44 kHz.

If you have time to experiment, try doing the conversion to ALAC with iTunes and see if you get the same results.

Hi,

I guess you're using Mac with it's optical output? It will only playback in 16 bit 44.1 kHz.

iTunes itself will happily play files of 24 bit and up to (at least) 192 kHz, you just need a DAC for that.

However iTunes itself will playback with the chosen sample rate whatever file and whatever sampling rate the file is in.

Software like BitPerfect will allow you to use iTunes and each song will play back with correct sample and nitrate.

You do need to use DAC to do that.

scrutinizer82 wrote:

Update.

I picked an AIFF file already in my iTunes Library and converted it to ALAC using that iTunes option. When I first opened Get Info of this newly created copy of the original AIFF file (300+ MB, 24/192) it showed...well it showed 192 MB with 24/192 too. How THAT could be possible? Decided to check again and of course MediaInfo Mac showed its true 24/44.1. Here we're. It seems that when converting iTunes just pull out the metadata of AIFF and applied to ALAC? How would you explain the wrong info?

Scrutinizer,

I converted a WAV 96/24 file to ALAC. iTunes thinks the result is also sampled at 96. And the ALAC bitrate of the new file is around 3100 bps, which is consistent with 96/24, and much higher than ALACs for 44/16 files. That of course does not mean that the conversion was accurate, only that is has enough bits to potentially be accurate!

And, the reading you are getting from MediaInfo certainly makes the whole iTunes conversion suspect.

scrutinizer82 wrote:

Is it a bug? Have they fixed this in iTunes 12?

Scrutinizer,

I do not know if it is a bug or an intentional design decision to not support hi-res files with Apple Lossless. Unfortunately, if you are working with hi-res audio files, Apple Lossless is not lossless. If they do plan to fix it, they are sure not in any rush, since essentially the same problem has been reported on this Forum for years. For your amusement (or not) here is a thread from 2009:

Re: Converting BACK to 24-bit WAV from 24-bit Apple lossless.... not possible?!

Hi,

no I don't mean optical drive, I mean the optical output of your Mac. When you use it, you only get the 16/44.1 out of it.

Ed 2345 wrote:

"Unfortunately, if you are working with hi-res audio files, Apple Lossless is not lossless."

Really? Can you back up that. It should be easy to prove. if it really is so. What kind of files don't fulfil that? Asking this because DSD files can't actually be tuned into other formats without losing data. Whether there is actually anyone that can hear the difference is another matter of course :-)

When using ALAC the sample rate should of course be the same as the original. So a 24/192 file should be that in ALAC version too. What should be different is the bitrate.

Why the Mediainfo Mac? (is this MediaInfo on App Store) showed different results, I don't know. Maybe it is not capable of showing iTunes files?

Looking at the web site, it doesn't seem to support ALAC files. It does support RIFF files? Not sure I would trust this info.

I still can't find any info whether it supports ALAC at all. Well anyway, iTunes and ALAC, with the right hardware support at least up tp 192 Khz ALAC files.

Apparently iTunes can't encode 24 bit 96 khz files back to AIFF but you could use something like XLD to do that.

Newme wrote:

....

Ed 2345 wrote:

"Unfortunately, if you are working with hi-res audio files, Apple Lossless is not lossless."

Really? Can you back up that. It should be easy to prove. if it really is so. What kind of files don't fulfil that?

Newme,

Simple enough to demonstrate. If you take a WAV 96/24 and use iTunes to convert it to Apple Lossless and then back to WAV (using "Automatic" setting in both cases), you end up with a significantly smaller file. Something gets lost.

Asking this because DSD files can't actually be tuned into other formats without losing data. Whether there is actually anyone that can hear the difference is another matter of course :-)

Wasn't referring to DSD, but it is an interesting question. The usual lossless formats, ALAC and FLAC, are designed to improve on the inefficiencies of PCM encoding as is used in WAV, AIFF, and audio CDs. DSD is a horse of a different color, as it is not PCM based at all.

Hi ed,

it must be that iTunes can't encode lossless files back to 24 bit. What I'm after is that the fault isn't in ALAC files but rather in iTunes not being capable to encode it back to 24 bits. If the end result with XLD is the same, then I would be worried as there would be something wrong with the ALAC conversion.