[speex-dev] First draft for Speex RTP profile - Please send your comments

Greg Herlein gherlein at herlein.com
Tue Oct 22 21:06:37 PDT 2002

> > I think the SpeeX frame format should not require negotiation of the
> > number of frames to be transmitted.


> Personally, I think it's good to make it part of negotiation for two
> reasons.


I agree with Jean-Marc.  We discussed this at length and agreed
that including in the packet the number of frames in the packet
is not useful.  Perhaps someone can explain why it would be?  

In general, most apps will use 1 speex frame per packet, simply
to keep latency down.  For streaming apps, perhaps multiple
frames might make sense... but in those scenarios, a pre-arranged
multiple frame per packet arrangement is likely better anyway.

As to multiple frames per packet in general, it can be
dangerous.  Packet loss with lots of frames in one packet leads
to much larger gaps in the audio.  And, since packet loss tends
to be bursty, even duplicate frames in successive packets is not
a good solution in many cases (and it doubles the bandwidth

I suspect that most applications will in fact use the default of
one frame per packet.  If dynamic changes are needed mid-stream,
they can be arranged out of band easily... the spec shows how to
do that via SDP/SIP.

<p>--- >8 ----
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