I've been playing around with WavPack and really like the idea of the hybrid two file system, one lossy file and one file that contains all the stripped out bits allowing someone to recombine the files for lossless reproduction.

This would be a very cool way to create files for both archive and iPod in one pass except the Wavpack lossy's won't play back on my portables.

Is anyone considering/working on a system that would create MP3's (preferably LAME) that would have an associated file that can be combined with the MP3 to create lossless reproduction?

Does anyone else think the idea has merit?

Best Regards,

Marcel

The lossy wavpack should play back on your portable if the lossless version plays. Since you have an iPod, you can always use Rockbox for the iPod.

I remember reading something suggesting something like this for LAME and said it wasn't possible. Not having any luck finding the thread though...

No.

I don't know much about mp3-encoding, but this are my first thoughts:

The hybrid modes of the lossless codecs divide the samples into two parts: The higher bits are stored into the main file, the lower bits into the reconstruction file (this is a very simplified description). So the reconstruction file contains the difference between the main file and the original.

With your method the differences in the reconstruction file surely will become greater, beacuse mp3 for instance can contain some phase shifts, which means that some samples are beeing shifted to one neighbour position into the file. If you then calculate the difference between the mp3 sample and the original sample at the same file position, it is very likely to become much bigger than the reconstruction difference of lossless hybrid codecs.

So i would think, that your whole reconstruction file would become bigger than a pure lossless file.

Sorry, not easy to explain with my bad english...

Thomas