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Rockbox mail archiveSubject: Re: AW: Question about CD-Quality and MP3Re: AW: Question about CD-Quality and MP3
From: Frej Bjon <fbjon_at_abo.fi>
Date: Thu, 02 Feb 2006 17:22:02 +0200 On Thu, 02 Feb 2006 16:37:29 +0200, Michael E. DiFebbo <medifebbo_at_rcn.com> wrote: > This is a common misperception, but at best it is only partially true. > The term "joint stereo" has two different meanings when used with > respect to encoding MP3s. > > The joint stereo method that you refer to is "intensity stereo." > Intensity stereo is only used by modern MP3 encoders for very low > bitrate files (lower than 96kbps if I remember correctly). For higher > bitrates, "joint stereo" refers to M/S stereo. Ah, how wonderfully unambiguous. Well, in that case, it used to be that you should use stereo encoding, but these days the encoders are smarter than that :). Now that you mention it, I do recall that encoders can decide frame-by-frame which method to use (M/S or separate channels), but I wonder how it's decided which is better. Encoding with both and picking the one with smaller size is trivial, but inefficient. Also, you say M/S is more efficient to encode when much of the source is centered and mono, but does the opposite apply? Is it less efficient if the stereo field is really wide? -Frej Received on 2006-02-02 Page template was last modified "Tue Sep 7 00:00:02 2021" The Rockbox Crew -- Privacy Policy |