[vorbis] [new?] Streaming technique

[Kristoff Bonne]

Greetings,

On Tue, 5 Jun 2001, Aaron Plattner wrote:
> Assuming bitrate peeling works correctly, what's preventing
> you from just taking a 128kbps stream and splitting it into
> a 64kbps sub-stream and a 64kbps "extra data" stream?  The
> second stream won't be a valid Vorbis audio file, but when
> combined with the 64kbps sub-stream, it'd be the original
> 128kbps stream again.  Right?  Am I misunderstanding
> something?

Two remarks (to continue this brainstorming-session):
- One of the things you should take care of; is that both 'streams' should
have the same bitrate (or a bitrate that does not vary to much vis-a-vis
eachother).

What I mean is this:
If the 2nd session that is started is an (additional) TCP-session; you'll
have to deal with the 'slow start'; having a quite varied bitrate at the
start of the session.

- Just a brainstorming-idea: this is also used for (say) digital
television; called 'hierarchical broadcasting'.
The same program is broadcasted as two different streams: one in SDTV
(standard definition) (say 4 to 6 Mbps); and one in HDTV (high
definition) in (say) 20 to 30 Mbps.
The SDTV-signal is broadcast using a modulation technique (like QPSK) that
has a lower bitrate but is more robust. The HDTV uses a
modulation-technique that has a high bitrate; but is less robust.
So, under 'good conditions', the HDTV-signal is receivable; and the user
gets a HDTV-picture. Under less good conditions (like further away from
the transmittor); the user still is only able to receive the SDTV-signal
so has a lower-resoluation picture.

In MPEG-video (and audio too, I guess); both streams are independant; so
the picture being transmitted in the SDTV-stream can also be found in the
HDTV-stream, but vorbis would have an advantage over MPEG for this!

Cheerio! Kr. Bonne.

-- 
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