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Rockbox mail archiveSubject: RE: What Is Dithering?RE: What Is Dithering?
From: Christopher Woods <christof_at_infinitus.co.uk>
Date: Fri, 17 Nov 2006 03:45:01 -0000 In a nutshell, dithering is A Good Thing, as it minimises error in resampled or down/upconverted signals, it's used a lot for waveform analysis (and audio work, particularly where high quality is sought), I know that dithering is definitely one of the things on my to-do-checklist whenever I'm doing audio editing in the 24- or 32-bit digital domain when I do my final master mixdown for CD audio publishing (which is 16bit). A lot of recording studios do all their work at 24- or even 32-bit (but 32bit is fairly overkill, 24 is fine) and only at the very last stage do they downconvert the final mix to 16-bit, as keeping your audio signals at as high a bitdepth as possible will preserve data which is more easily lost through multiple generations of signal processing or edits. In the context of your device, I guess it could be applied like so: if you have, say, 24bit audio but your device can only output 16bit due to hardware constraints, the firmware will (have to) resample the audio realtime, and dithering can improve slightly on the quality. All to do with Nyquist frequencies, signal aliasing... It's messy stuff. And I'm doing a degree on all this! I still don't fully get it, it's bloody complicated. I guess a comparable analogy (best I can think of right now) would be if you take a large image, and resize it to a smaller size - if you have your settings to just go with each pixel's nearest neighbour when you shrink the image, you'll get uneven lines, jaggedy edges and it'll look a bit poor... Whereas if you set your image program to do bicubic or bilinear resizing, it looks at the pixels, their relationship to the ones next to them, and 'redraws' the image in a sense, blurring together areas for want of a better description, to produce a more aesthetically-pleasing result - lines look smoother, colours blend and gradient better... The Wikipedia article on it is pretty informative: http://en.wikipedia.org/wiki/Dithering. > -----Original Message----- > From: Rich De Steno [mailto:ironrock_at_verizon.net] > Sent: 17 November 2006 01:44 > To: rockbox_at_cool.haxx.se > Subject: What Is Dithering? > > The Sound Settings menu has a "dithering" option, yes or no. > What effect does this have? > > > Received on 2006-11-17 Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy |