Vorbis - Nov 2001 - Multiple tracks per file, or continuous audio support

>This doesn't work with MP3s.  MP3s use frames in the
>frequency domain with overlapping time spans...the
>result being that at least a half-frame of silence is
>appended to the end of a track.  So you have a choice:
>record the spanning tracks separately and hear a
>distracting "pop" as the player switches between them,
>or encode all the continous tracks together and
>discard their identities, with the side effect of
>creating a potentially huge file.
>
>I saw a post on MP3.com (somewhere under the Rio Volt
>SP250 or that JVC thing) that said the Vorbis will
>conquer this problem.
>
>My question is:  how?  Vorbis records in the frequency
>domain too, right?
Vorbis has the same problem, BUT has a technique to deal with it correctly.
In the bitstream, there's sufficient information that the decoder knows
(this has worked since beta1, and even earlier) which bits to discard from
the start and end - the output is, as a result, exactly the same length (in
samples) as the original input.
>
>I want my cake and I want to eat it too.  I either
>want fully continuous-capable individual tracks with
>no discontinuities, or I want a way to mark a single
>large file with several embedded tracks, AND be able
>to navigate into them randomly, AND be able to split
>them into little files later in case I'm making a
>compilation.
Vorbis actually gives you BOTH of these - as I described above, the
individual tracks work fine. Also, vorbis lets you have multiple streams in
a single file, following each other - so you could have one file with a
seperate stream for each track, which gives you everything you wanted
(although player UI typically makes this hard to take full advantage of -
write your own player if that's a problem :-)

Michael

--- >8 ----
List archives:  http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
To unsubscribe from this list, send a message to
'vorbis-request@xiph.org'
containing only the word 'unsubscribe' in the body.  No subject is
needed.
Unsubscribe messages sent to the list will be ignored/filtered.

Alright, I'm trying this message again.  I'm receiving
tons of traffic on the Vorbis list, but so far my
submissions have been silently rejected.

I'm very concerned about a serious usability feature
lacking from the current MP3 spec, and possibly from
Ogg Vorbis.  It has nothing to do with bitrate, but
everything to do with quality.

I listen to progressive rock and live albums quite a
bit.  Often artists will release CDs with continuous
music that spans several tracks.

This doesn't work with MP3s.  MP3s use frames in the
frequency domain with overlapping time spans...the
result being that at least a half-frame of silence is
appended to the end of a track.  So you have a choice:
record the spanning tracks separately and hear a
distracting "pop" as the player switches between them,
or encode all the continous tracks together and
discard their identities, with the side effect of
creating a potentially huge file.

I saw a post on MP3.com (somewhere under the Rio Volt
SP250 or that JVC thing) that said the Vorbis will
conquer this problem.

My question is:  how?  Vorbis records in the frequency
domain too, right?

I want my cake and I want to eat it too.  I either
want fully continuous-capable individual tracks with
no discontinuities, or I want a way to mark a single
large file with several embedded tracks, AND be able
to navigate into them randomly, AND be able to split
them into little files later in case I'm making a
compilation.

Doesn't this make sense?  Has this already been done? 
I really don't want to jump on the highly-compressed
audio bandwagon until this problem is definitely
solved.

That said, I've gotta say that the examples I've
encoded with OggDrop sound pretty damned amazing.  I'd
say they sound a bitrate better than MP3 with LAME
(like, 128 Vorbis [probably like 133 VBR] sounds as
good to me as 160 MP3 CBR).

Anyway, thanks for any and all comments/pointers/etc.

Mike

__________________________________________________
Do You Yahoo!?
Find a job, post your resume.
http://careers.yahoo.com

--- >8 ----
List archives:  http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
To unsubscribe from this list, send a message to
'vorbis-request@xiph.org'
containing only the word 'unsubscribe' in the body.  No subject is
needed.
Unsubscribe messages sent to the list will be ignored/filtered.

> I guess I'm skeptical of the first solution.  I *did*
> encode two tracks that play continuously, and played
> them back in Ogg-enabled Winamp.  There's a small pop.
>  This could be the player, though, cheating with its
> own zero frames.
> 
> Anyone know of a way to check this out?  Any players
> that are especially Ogg-smart, in that they drop
> silence/breaks/etc.?
this happens becuase winamp's standard output plugin closes and repoens the
WaveOut device between tracks. I use a gapless output plugin
[http://www.geocities.com/outgapless/] and it sounds beautiful with OGG
files. Even MP3s sound acceptable with it. Give it a try.

EDB

--- >8 ----
List archives:  http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
To unsubscribe from this list, send a message to
'vorbis-request@xiph.org'
containing only the word 'unsubscribe' in the body.  No subject is
needed.
Unsubscribe messages sent to the list will be ignored/filtered.