Comments on: Do I need to dither when converting to mp3? http://ameone.com/2008/07/27/do-i-need-to-dither-when-converting-to-mp3/ music, writings and words for the eccentric Tue, 08 Sep 2009 10:28:31 +0000 hourly 1 http://wordpress.org/?v=3.0.1 By: screwtop http://ameone.com/2008/07/27/do-i-need-to-dither-when-converting-to-mp3/comment-page-1/#comment-84 screwtop Tue, 08 Sep 2009 10:28:31 +0000 http://ameone.com/?p=188#comment-84 I've wondered about this too. I know some MP3 encoders are limited to 16-bit (or at least PCM) input, but I would use a higher-resolution source by preference as there would be less quantization noise for the encoder to have to deal with. I think the standard Ogg Vorbis encoder can accept floating-point waveform input, for example. The problem I'd envisage with dithering before encoding would be that there's no guarantee that the effect or character of the dither would be preserved in the encoding. This is especially true for noise-shaped dither, which has more energy in the high frequencies and would likely be completely discarded by the encoder. AFAIK, most lossy codecs operate on floating-point internally, so there may be some benefit to using dither (or decoding to more than 16-bits) on playback. There are certainly decoders that implement dither, and I assume they wouldn't bother if it weren't beneficial. Good sonic food for thought! :) Cheers. I’ve wondered about this too. I know some MP3 encoders are limited to 16-bit (or at least PCM) input, but I would use a higher-resolution source by preference as there would be less quantization noise for the encoder to have to deal with. I think the standard Ogg Vorbis encoder can accept floating-point waveform input, for example.

The problem I’d envisage with dithering before encoding would be that there’s no guarantee that the effect or character of the dither would be preserved in the encoding. This is especially true for noise-shaped dither, which has more energy in the high frequencies and would likely be completely discarded by the encoder.

AFAIK, most lossy codecs operate on floating-point internally, so there may be some benefit to using dither (or decoding to more than 16-bits) on playback. There are certainly decoders that implement dither, and I assume they wouldn’t bother if it weren’t beneficial.

Good sonic food for thought! :) Cheers.

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