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Old 2005-02-17, 06:50 AM
4candles 4candles is offline
 
Join Date: Nov 2004
Re: Neuros II and Flac

You should look at the Rockbox project to port their open source jukebox firmware to the iRiver H120/H140 players. The iRiver port of Rockbox is well-advanced, and you can install it today on your H120 or H140 - but the new audio playback system isn't yet written, so there is no actual sound.

Rockbox was originally written for the older Archos HD-based portables, which did all audio processing via a hardware MP3 decoder chip - so all Rockbox had to do was feed that chip with MP3 files.

For the iRiver port (and in-progress ports to other devices without hardware audio decoders), the Rockbox developers are designing a new audio playback system - and a fundamental design goal is gapless playback. I believe that an audio playback system either has to be designed from the start to be gapless (like Rio did with the Karma), or otherwise it will never work flawlessly.

The basic design is two split the memory buffer into two parts - one part containing the compressed data waiting to be decoded, and another containing uncompressed PCM samples ready to be sent to the DAC. As long as the PCM buffer is never empty, playback will be gapless (subject to issues such as padding silence in the final MP3 frame etc, but that is a different problem with a different solution).

Rockbox on the iRiver will also feature probably the widest range of audio codecs available in a portable player - currently, MPEG (layers 1,2 and 3), WAV, Vorbis, FLAC, AC3 (aka A-52) and Wavpack decoders are actively being worked on by the developers, and this is before Rockbox has a proper audio infrastructure implemented.

The only restrictions on codec support will be that the decoder must be released under an Open Source license compatible with Rockbox (the GNU GPL) and that it is capable of running on the iRiver's 140MHz CPU.

The Rockbox developers are very open to feedback or questions - drop into IRC at http://www.rockbox.org/irc/ or browse the website.

Only problem is that the H120/H140s are now out of production, so suppliers are hard to find.
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