24/96 (HIRES files for playback...)

[znorter]

Hi!
Do you know if RockBox for iPod is able to playback .FLAC and/or .WMA and/or .WAV files at 24bit/96...or higher formats?
very thank you

[preglow]

Rockbox plays back files of higher bit depth and higher sample rates than 16 bits and 44100 Hz just fine right now, but not with full quality. Here is what happens:

• Bit depth: Rockbox will decode all formats to as high a bit depth as possible for both lossy and lossless formats. All internal processing is also done at 32 bits bit depth. However, all current targets truncate to 16 bits at the output. This can be fixed if someone cares enough about it to do some programming, but the DACs in current targets really aren't good enough for this to make much sense.
  
• 
  Sample rate: Rockbox will decode higher sample rate files (like 96 kHz) just fine, but resamples to 44100 at the output, so some quality is lost (especially considering the extremely crappy resampler we use). Again, someone needs to care enough to do some programming to fix this, and it makes more sense to fix this problem than the bit depth problem.
  

[znorter]

Thank ypu, Preglow.

So, "the problem" is (are) DACs, 'cause Rockbox read all the HIRES formats also installed on iPods, right?

BUT, if the iPod is connected via USB (or another portable player that has this output) to an hiend DAC that accept 24/96?
You think I will lsten the hires without truncate something?

Again, thank you, Luca

[preglow]

Well sure, if a player is able to send it's audio via USB to another DAC, anything could be possible. I don't really know the limitations of the USB audio protocol, though.

[znorter]

Hi, preglow.
This is the protocol link, I am not able to understand IF...24 bit...is possible...

http://www.usb.org/developers/devclass_docs/audio10.pdf

[znorter]

FIND!!!

Thanks to Apogee forum (and Google:) this is a quote:

   Can the Mini-Me handle 24/96khz sampling rates through USB?
   Though the Mini-Me can convert at sample rates up to 96 kHz via the AES and SPDIF output, the USB driver can accommodate only sample rates up to 48 kHz. Because of the bandwidth limitations of the USB bus 96khz recording is not attainable.
POSTED:    2003-07-11 12:38:11

So...NO, the USB is NOT able to drive 24/96

[Chronon]

Please remember not to double post.  

[saratoga]

Hi, preglow.
This is the protocol link, I am not able to understand IF...24 bit...is possible...

http://www.usb.org/developers/devclass_docs/audio10.pdf

Maybe the USB 1 spec isn't the best place to look for USB 2 audio.

So...NO, the USB is NOT able to drive 24/96

They're obviously referring to that specific (USB1) device.  USB2 has enough bandwidth to carry dozens of 24/96 streams.

That said, 24/96 playback is pretty useless anyway.  Just use 16/44.1 and stop worrying.  

[znorter]

Ok...thank you.

[Lornecherry]

Over at Headfi, there's been quite a bit of discussion about this (by "this", I mean 24/96 from the ipod), since, although itunes fully supports 24/96 WAV, the native firmware on the ipod does not.

24/96 is especially relevant now with so many Wadia iTransports being sold and now in the hands of would-be audiophiles. Because the Wadia bypasses both the ipods's internal amp and DAC (thus outputting bit-perfect digital); it seems the perfect medium for some the great 24/96 material now available.

The Wadia truly is the missing link in making the ipod equivalent to a high end transport. With Wadia releasing a $1500 DAC/headphone amp combo soon (shown at CES) the need for someone to develop native 24/96 support grows.

(Those that are familiar with Wadia DACs in general (they call them decoding computers) know how wonderful they sound and that ... most of their stuff is north of $6K.)

The only other portable player to support true digital out is the older iRiver 120/iHP-140, but with the release of the new Ibasso D-10 DAC/AMP (supports optical in and is the size of the iRiver) there is also a movement towards higher end portable devices with true audiophile capabilities.

If a developer were to take on this project (24/96) WAV or FLAC; you'd earn a very strong following over at headfi .

[znorter]

Thanks for the feedback...
...but I hope "they" will see more accurate the present digital music that is 24/192!
All the "audiophile" version of liquid music is and will be 24/192...
ciao

L.

[saratoga]

Theres no one here with a $1500 Ipod accessory, so if you want to use it, you or one of your fellow owners will likely have to reverse engineer how the device works and implement support for it.

[znorter]

I am NOT (and happy to be not) one of them...but..."all the world is a stage!"
 

[saratoga]

Well, if you don't have the device, and we don't have the device, theres no sense posting about it here.

[znorter]

ok...admimistrator in chief:
delete me...
bye