General Question: Mp3 Decoder Quality

[BdN3504]

After having read the Devicechart, i noticed that all the new players don't have a hardware mp3 decoder. I was wondering if there's a difference in quality between hardware and software decoding.
Does it affect the performance of a player, if hardware takes care of decoding? If so, why is there no new player featuring a hardware decoder?

(If i put this thread in the wrong section, please advise me where to put it)

[bascule]

1. Hardware decoders are potentially harder or in fact impossible to upgrade to support new encoder functionality
2. Generally, you can only have one per device, limiting the device's usefulness
3. They *probably* have some power efficiencies, but the flexibility of multiple software codecs (cf Rockbox) massively outweighs that slight disadvantage.

[karashata]

I'm certainly no hardware expert, but I would hazard a guess that the older players used dedicated hardware decoders because the processors available weren't powerful enough at the time to do software mp3 decoding.  The limitations of a dedicated hardware decoder is that it *only* supports the mp3 format (though I think .wav files can be played back as well, as they're already PCM), and some times the bitrates supported are fixed.

Software decoding allows for more supported formats (some common ones being OGG Vorbis and WMA), and Rockbox has written and ported codecs for less commonly supported formats (such as FLAC and SPC, for a full listing go here.)  I would expect that sound quality between a dedicated hardware decoder and a software codec would be fairly equal, as the quality of the mp3 would really depend on its bitrate.

[BdN3504]

Thanks.

[dreamlayers]

MP3 decoders shouldn't differ much unless they're broken.  Rockbox uses the MAD decoder, which should provide high quality output.  It provides 24 bit output, and Rockbox has a dithering option which could increase quality beyond what's possible with 16 bit decoders.