Non-Portable Audiophile Rockbox based DAP

[mcmurray]

Hi guys.
I am in the near future beginning design of a high quality desktop DAP that plays everything up to and including 24bit/192khz PCM and FLAC.  Storage will most likely be SATA with capacity exceeding 1Tb.  

I am wondering if there would be any interest from you guys in a non portable player?  Do I have the ok to port Rockbox to my player once the hardware is up and running?

I am also considering making the hardware completely open. i.e. publishing everything as it is designed such as schematics and pcb layouts.  Once I have a working product I will then consider minimising the size for a portable unit.

Tell me what are your thoughts or what features you would require to make an item such as this interesting to you?

[krazykit]

I am wondering if there would be any interest from you guys in a non portable player?  Do I have the ok to port Rockbox to my player once the hardware is up and running?

Rockbox is licensed under the GPL, so you're more than welcome to port it to any platform you like, so long as the code is also GPL.  Good luck on your project

[mcmurray]

Sweet.  Programming was never my strongest attribute but I was looking through the source code last night and it reads quite easily.  I think that resource will be a huge help.  At one point I was contemplating writing the OS from scratch.

[LambdaCalculus]

Sounds like a great project! A small desktop-sized jukebox running Rockbox, and storage of upwards of 1 TB... oh so sweet!

So what hardware are you looking to design around? Have you got an idea for a CPU, display, and control scheme? Or are you looking for suggestions?

[mcmurray]

At this stage I have some ideas.  High-resolution 24bit playback with a quality DAC/output stage is my main requirement because I have a use for it and right now there is nothing on the market that suits my needs.  I would like the DAC to be on-board but maybe SP-DIF and external DACwill be an option.  I'm considering the Coldfire line of processors.  As for the display and control scheme I envision something simple for the prototype such as a monochrome or greyscale display and standard push buttons for play/pause/navigation etc.  

A fully featured remote might be on the cards once the basic system is working.  

I'm not familiar with the rockbox interface but I will have a play with it soon when I get a portable player.  I am looking for suggestions especially on features and things like control and displays so keep them coming.

[LambdaCalculus]

If it's Coldfire you're thinking of, then try to hunt down a DAP that uses the same CPU, such as the iriver H100, H300, or iAUDIO X5 and M5 models. That way, you can get a feel for how Rockbox will perform on the device.

[mcmurray]

Will do.  I was thinking about picking up an iAudio x5.  What would be your ideal rockbox CPU?

[LambdaCalculus]

Coldfire. It's well documented, powerful enough to perform software decoding, and already well supported by Rockbox.

If I remember correctly, the Coldfire CPU can be clocked up to 140 MHz, but a little Googling will bring forth the information we seek.

[GodEater]

Will do.  I was thinking about picking up an iAudio x5.  What would be your ideal rockbox CPU?

ARM - it clocks higher - so a Freescale something or other would be nice

[etienne]

I have a very similar requirement to this.

I run http://www.ambisonia.com, a site that distributes surround sound files in a next-generation format called ambisonics.

I am looking for a harddisk based audio player that is capable of decoding Ambisonic files to multi-channel AV receivers.

The point being that an Ambisonic file can be 'decoded' to any speaker layout (stereo, 5.1 7.1, or even height based systems)... and that the 'decoding' needs to be done in software.... but most users dont want to have to bother with setting up and using their computers. So a Harddisk with a CPU that can do some DSP is perfect.

There are 2 ways that audio streams can get *out* of the system ... analog or digital. digital is clearly cheaper, but analog may be technically easier given that the aim is to get 8 channels out (to arrange speakers in a cube).

It would also be extremely powerful if the harddisk also had Ethernet connectivity with the capability to subscribe to podcasts (this could be managed via a web interface... served by a very simple and small Http server).

Anyway, I'm very interested in this project. Please keep the discussion going.

Etienne

[mcmurray]

Sounds interesting.

I wasn't planning on making the unit multi-channel at first but I don't see why it couldn't decode your files and output them digitally.  However you would need to provide complete information about the codec used.

I will keep you up to date on my progress, however my engineering thesis is due soon and is taking up all my spare time at the moment.  After that I'll have plenty of time.

[Multiplex]

You don't need real hardware to paly with the Rockbox UI - there are simulators for each of the paltforms, bottom item on this page http://www.rockbox.org/twiki/bin/view/Main/RockboxExtras

It's a sad admission but I might start using the Sim for my DAP as a music player on my PC...

[GodEater]

It's a sad admission but I might start using the Sim for my DAP as a music player on my PC...

Nothing sad about that - I already do...

[DefineByte]

I would love a low-power hard disk based desktop DAP with S/PDIF (with bit perfect output).

Up to this point I've been looking at running a Rockbox sim on a Via Epia based setup but a bespoke design would be brilliant.

[Llorean]

Wouldn't a "low power HD-based DAP with S/PDIF" be "The iRiver H100 series"?