Being an IT person (like others on the forum) I guess I am less scared of some of these digital processes.
Upsampling doesn't destroy any information. (Downsampling might.) For example, if you have a photo sized 300 pixels by 200 pixels on computer, and expand it to 600 by 400 pixels, you do not destroy any original information. You just make it bigger. There are various ways of expanding the image. You could create 2x2 pixel blocks exactly corresponding to the original photo. In which case, the photo looks exactly the same, just as blocky, except physically bigger on the screen. Or, you could expand it using a "dithering" technique which interpolates values for each of the pixels at the new resolution, from values of pixels at the old resolution. Either way, no information has been lost (and I mean none, nada, zip, not a jot) and one may argue that a dithered up-scaled picture might be a more natural representation for the human eye. If it is upscaled in this way, and downscaled in a compatible fashion to the original size, you still get exactly the original photo. Exactly, I mean exactly down to the last 1 or 0! Try it. Repeat the process ten times, a million times. The end result is exactly the same as the original, down to the last 1 or 0. It's just the way it works. (I might add that if anyone claimed to *see* a difference in the end image, it could only be put down to a placebo effect :-p Ooh!) The issue for red book is that the original signal is encoded with a 16 bit word length. Upscaling involves no degradation to the signal, in fact might enhance it subjectively (but not in terms of its content of absolutely accurate original information, which remains utterly unchanged). And if this upscaling is done to a sufficient degree it means that subsequent volume attenuation might still not impact that information content - you still have the original "resolution" encoded in the signal. (This depends on the level of upscaling, and the amount of attenuation - which is why it's recommended to stay in the higher side of the digital volume range.) If you're not so familiar with IT concepts it sounds scary, but really it does work this way. Regards, Darren PS: Eiret, I'm glad your calculator agrees with me that upscaling from 16 bit to 24 bit multiplies the numbers by 256 :-) PPS: Anyone wanting to know how to check for computer files being bit-identical should google "checksum". -- darrenyeats SB3 with Inguz -> Sony DAS-703ES DAC -> Krell KAV-300i -> PMC AB-1 (home-made room treatments and supports) ------------------------------------------------------------------------ darrenyeats's Profile: http://forums.slimdevices.com/member.php?userid=10799 View this thread: http://forums.slimdevices.com/showthread.php?t=38233 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
