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View Full Version : Gapless playback with mp3 - another shot



Familie Tromp
2005-03-10, 05:59
So a mp3 file must contain info according to a sort of protocol and due to this fact it can be possible for me to hear a sort of 'gap', a 'hop' or something before actually playing the next track when the transition is audible (f.e. by classical music and/or live recordings (applause)).

If the slimdevice is a merely simple piece of device than it must be possible to change the server software a that manner that empty frames will be replaced by the starting frames of the next song, and so on.... If it is software than it can be changed! Real-time streaming you know.

I know it's a lame-feature and I am not aware of something being used in other encoders. Maybe lame leaves a fingerprint of itself in de mp3 file where it can be scanned by slimserver.

My library contains 7xxx songs on this moment delivering an great amount of classical pieces and live recordings. It's rather irritating to hear gaps between tracks when I am not expecting them....

<off topic>

It's surely a nightmare to dig into this mailbags to find an anwser. A general forum would be a nice feature! ;)

</off topic>



On Wed, 09 Mar 2005 18:50:45 -0800, Phil Karn <karn (AT) ka9q (DOT) net> wrote:

>> Can somebody give me some background on gapless playback? I don't
>> understand why it's a big problem.


I'll try in a non technical way.

The mp3 container has to be specific size increments, so you end up
with empty data at the end of most tracks.

The hack to make mp3 gapless is just that - a hack, it steals bits
from the next song during encode to make the file be the perfect size
to not have empty filler.

With mp3's encoded this way, some players can achieve gapless with
mp3, but it's a hack since it takes some bits from the next track to
do so.

There is some talk of putting mp3 in an mpeg4 container, which would
allow "true" gapless (no theft of bits needed) but I don't know if
players will ever support. I think winamp already does, but I think
they are one of the only ones.

-- http://mpeters.us/

mherger
2005-03-10, 06:50
[..]
> <off topic>
>
> It's surely a nightmare to dig into this mailbags to find an anwser. A
> general forum would be a nice feature! ;)
>
> </off topic>

http://forums.slimdevices.com

--

Michael

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