I'm looking for good resources on writing my own MP3 decoder. Sounds silly, I know. This is for an embedded system. I don't think mpg123 will compile easily for an embedded system.
I'd prefer not to read through the whole spec trying to figure out the decoder myself. Anything to help me along would be awesome.

Thanks!

What about using an hardware decoder?

libmad has a integer decoder for those devices with no floating point support.

But yeah, if you have the option of using a hardware decoder, do it. Sparkfun sells some

MP3 Decoder... what do you mean by that:

like a MP3 File Parser (some programs have those)
or a Codec (Play Em!)

google a program called MPXPlay. made in OpenWatcom 1.30 emulates every Soundboard with OGG\MP3\WMA\ect. support! Source Available! Get IT!

I know some OS's if needed that work under ROM:

FreeDOS - Good ol' DOS, the mighty Allegro Started on DOS!

DSL - A VERY FREAKIN SMALL Linux DISTRO!!! CLI and no packs (for minumum download)!

Using a hardware decoder is the best option for embedded devices since they've got almost no processing power/memory to speak of.

I'm curious though: would the device need to be able to parse the files at all? Or can you just send an entire .mp3 file straight to the chip raw?

I've heard it is very hard to do. (sorry I can't be more helpful )

Wow, $11! -- I remember seeing the "build it yourself mp3 player" project back in like 99 or so, and the IC you had to buy was like $60+ (the total parts cost was around $110, IIRC)

Well I wanted to do it in software so I can save money on the chip. It's not $11, it's $11 + the cost of all the components needed to drive it. Timing crystal, resistors, capacitors, board, power supply, etc, etc. Sparkfun does have this breakout board with everything, for $40.

I suppose that's what I'll go with since it's easiest. It's an unfortunately large amount of my budget though

Well, if you go for the software way, you'll anyway need a cpu, maybe it would be less expensive, but then you'll need the circuitry to program it

I don't know on which dependencies it relies on, but IIRC gcc can cross-compile to arm processors.