[vorbis] Streaming Considerations.

[Peter Shore]

----- Original Message -----
From: "Adam Scriven" <scriven at lore.com>
To: <vorbis at xiph.org>; <vorbis-dev at xiph.org>
Sent: Friday, July 28, 2000 8:57 AM
Subject: [vorbis] Streaming Considerations.

> I was thinking about this streaming thing again (thankfully, not about
the
> info stream, but the audio stream. 8-) ), and I was wondering if it
would
> be streamable like MP3, or more like Real Audio.  MP3 players, like
WinAMP,
> can stream without a special server.  This may not be as reliable,
> streaming over HTTP, but it is quite handy.  Will this be possible
with
> Vorbis (dependent on the plug-ins)?  And, if it IS possible, it should
also
> pre-buffer the next coming song, if possible, so that the audio stream
> pauses as little as possible between songs, similar to how WinAMP does
it.

Having work extensively with Windows Media and its player control for
embedded objects, I was wondering very much the same thing.

Something many people don't realize is that even using just the http
protocol, there are radical differences in streamability between file
formats. Compared to ASF audio/video, MPEG audio/video streams poorly
and unreliably. The former is not cached at all on a hard drive, but
downloaded direct to memory - usually with just enough data to maintain
a 5-second buffer. MPEG audio/video, on the other hand, is read only
from a hard drive cache.

In terms of practical consequence, at modem bitrates a large MP3 encoded
at 20k can take a full minute to begin playing via any protocol, whereas
a 20k ASF/WMA file will begin streaming within seconds. At broadband
bitrates, a 160k ASF will stream much more reliably than a 128k MP3 -
and is far less prone to interruptions due to temporary bandwidth
drop-off, and to flutter due to competition for computer bus resources.

So I'm hoping that OGG, unlike MP3, is a non-cached file type like ASF
(& which can also be a strong security feature for artists wishing to
stream original content).

In the long term, streamability plus adaptability to multichannel audio
(beyond just 2-channels), are what I think will be the most important
factors in the success of any format. An embeddable player object and
control (or compatibility with an existing audio/video player like Real
or MPlayer), I think are also very critical.

Haven't seen much discussion addressing any of that.

Regards,
- Peter

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