Rockbox.org home
release
dev builds
extras
themes manual
wiki
device status forums
mailing lists
IRC bugs
patches
dev guide



Rockbox mail archive

Subject: Re: Gapless Playback

Re: Gapless Playback

From: BlueChip <cs_bluechip_at_webtribe.net>
Date: 2005-02-21

Thanks Johan. So the bottom line is no gapless mp3gain'ed files, all else
is cool ...That's acceptable (well, for me, for now) as I have no gapless
tracks.

As for undo, I can think of a few obscure reasons - but they are obscure
and I just wanted to cover my bases. I suppose there's nothing to stop me
knocking up little util to suck it out and dump it as "myMp3File.ape"
should the need ever arise - is your util online?

Is there any particular reason (which I may have previously missed) to
_not_ include APE-skipping code? I can fully understand why adding full
APE tag support is overkill* ...I mean if you add APE, where do you
stop? But an "if" statement to ignore it completely seems reasonable -
perhaps there is some more fundamental issue I have missed?

*It would mean a lot of code in the core which is currently VERY full, and
(afaik) offers nothing that is not offered by ID3 - which is fairly well
supported already.

Of course there would be no reason at all not to write a PLUGIN with Full
APE support ...but the gapless playback support _needs_ to be in the core code.

BC

>BlueChip <cs_bluechip@webtribe.net> writes:
>
> > What preisely will be the result of me attempting to play any of these
> > files? Maybe a small gap or squeak or a full blown crash?
>
>Under normal circumstances, nothing special will happen (except that
>all tracks sound at more or less the same volume level).
>
>When using continuous (gapless) play, a small disruption may be heard
>when switching tracks, due to the APE tag that is not skipped.
>Unless you have prepared your mp3 files for gapless play (see the
>discussion in other threads), you won't notice.
>
> > Is there any sotware available that will strip my APE tags and store
> > them away so I can put them back later (in case I want to modify the
> > tracks)? Maybe a special version of MP3Gain which stores a database
> > rather than embedding the information we require?
>
>Well, my software does exactly that ;-). Mp3gain can do it as well:
>just save its output somewhere.
>
>But actually, I still have to find a good reason why I would ever undo
>the mp3gain changes. If information was lost during the mp3 gain
>process, it will not come back.
>
>I mp3gain per album (so the track loudness relative to each other
>remains unchanged, but the average album loudness is normalized), and
>my software produces a data file like this (which is just a Perl
>version of the mp3gain output):
>
> $VAR1 = {
> '04_I_Don\'t_Wanna_Go_Home.mp3' => {
> 'dbgain' => '-1.530000',
> 'maxggain' => '176',
> 'maxampl' => '27339.484786',
> 'applied' => '-1',
> 'mp3gain' => '-1',
> 'minggain' => '127'
> },
> '03_Time.mp3' => {
> 'dbgain' => '0.030000',
> 'maxggain' => '210',
> 'maxampl' => '22533.201059',
> 'applied' => '-1',
> 'mp3gain' => '0',
> 'minggain' => '59'
> },
> '"Album"' => {
> 'dbgain' => '-1.240000',
> 'maxggain' => '210',
> 'maxampl' => '27339.484786',
> 'mp3gain' => '-1',
> 'minggain' => '59'
> },
> ... more tracks ...
> 'dir' => 'other/The_Alan_Parsons_Project/The_Turn_Of_A_Friendly_Card'
> };
>
>The 'applied' value (same for all tracks) can be used to undo the
>mp3gain changes:
>
> mp3gain -g <value> ...files...
>
>-- Johan
>_______________________________________________
>http://cool.haxx.se/mailman/listinfo/rockbox

_______________________________________________
http://cool.haxx.se/mailman/listinfo/rockbox
Received on Mon Feb 21 00:54:40 2005


Page was last modified "Jan 10 2012" The Rockbox Crew
aaa