Rockbox mail archiveSubject: Re: a lot of questions here
Re: a lot of questions here
From: Andrew Hart <ahart_at_dim.uchile.cl>
Date: Thu, 08 Mar 2007 16:28:18 -0300
Tyler Wood wrote:
> Ah, that helps greatly- I was just curious where I could find these options. Btw, I'm getting the ipod video on Saturday (bye-bye, PNY vibe 2 gb player).
> Oh, those other questions were, I believe,:
> How does .ogg at 64 kbps compare with mp3 ranging from 96 kbps to 192 kbps? (with 3500 files).
Sorry, I meant to reply to this last week, but forgot. I don't recall
seeing a response to this question, so here goes.
ogg at approx. 64 kbits can probably compete with mp3 at 80-96 kbits.
Ogg is especially good at low bit rates, much better than mp3, but this
is not true at any higher bit rates. At 128 kbits, mp3 and ogg are
reasonably comparable. I've seen reports of double-blind studies done
about these two things on Hydrogen Audio. As to which is the best at
bit rates higher than 128, I haven't seen any reports of studies.
Generally speaking though, transparency for most people occurs in the
range 160 kbits to 192 kbits in terms of mp3 encoding. However, there
are people who can distinguish higher bit rates than these from the real
thing, but audiophiles such as those are in a minority. Lower bit rates
like 64 and 96 really are substandard and sound pretty terrible.
As a general guide, music really shouldn't be encoded at anything less
than 128 kbits, and if you are going to encode at less than 128 kbits,
it might pay to use ogg. If you're unhappy with 128 kbit mp3,
try 160 kbit or 192 kbit, but any more than this would probably be
overkill for many listeners. On top of this, many digital audio players
have fairly poor dacs and output amplifiers, so the increase in file
sizes wouldn't necessarily be worth the miniscule improvement in sound
quality obtained. The hardware in many players simply can' take
advantage of the extra audio information. This is not a criticism of
players, its just simple physics. High quality DAC and output
amplifiers require more power which is a limited resource on these tiny
devices. Using higher quality parts would result in shorter battery
life or larger batteries (and more bulk). I do expect the audio quality
to improve as time goes on.
There is always a trade-off between quality and file size. Higher
quality means larger files. The most important thing is to choose a bit
rate encoding that satisfies the quality you're prepared to tolerate and
your storage requirements (that is, how much music you want to cram onto
P.S. For the audio oficionados amongst us, I've glossed over quite a
few details here for the sake of simplicity, e.g., the fact that ogg is
a vbr format and does not have a constant bit rate mode like mp3 does, etc.
Received on 2007-03-08