[Live-devel] Requesting Book recommendations

[Ross Finlayson]

>Would anyone care to recommend a book that can give me
>a good overview of the current state of streaming?

I suggest also asking this on some other, more general 'streaming' mailing 
list - e.g., "advanced at lists.infotoday.com" (although you tend to find a 
lot of Microsoft-brainwashed people on that mailing list).

>I keep thinking that its going to converge on some standard (I once
>thought that would be MPEG4) but that doesn't seem to be the
>case.

Well, note the distinction between *protocols* and *codecs*.  (MPEG-4 is a 
codec.)

As far as protocols are concerned, there's no doubt: RTP is the 
winner.  Witness the recent explosion in VOIP (voice over IP) - which uses 
RTP - plus the fact that RealNetworks is migrating from their own 
proprietary protocol to RTP, plus, of course, that Apple has used RTP in 
QuickTime for years (including in their new "iChat" video streaming stuff).

Codecs, however, are a different story.  Codecs continue to evolve 
(improve), so we're unlikely to find one single standard video codec and 
one single standard audio codec anytime soon.  But here's what I'm seeing 
(IMHO):

For video: For high bitrates, MPEG-2 is not likely to go away anytime soon, 
as there's a *lot* of legacy MPEG-2 content (and hardware) out there - 
e.g., DVDs and cable/satellite TV.  At lower bitrates, H.263 is still 
seeing lots of use (e.g., in videoconferencing, including Apple's new 
"iChat").  At lower bitrates still, MPEG-4 is getting used more and more, 
although it has been stymied so far by interoperability problems (different 
companies' implementations of MPEG-4 video don't always work 
together).  Lately, I've been seeing more and more interest in H.264 video 
(aka. MPEG-4 AVC, aka. MPEG-4 part 10), which has even better compression 
than regular MPEG-4.  (BTW, H.264 will get supported in the LIVE.COM code 
when someone wants it.)

For audio: MP3 (MPEG-1 or 2, layer III) is, of course, the standard 
'legacy' audio codec, although it still tends to be streamed over TCP 
(e.g., HTTP) far more than over RTP.  AAC (MPEG-4 audio) is getting lots of 
momentum these days, thanks in part to Apple's use of it in "iTunes".  For 
low-bitrate audio, there's lots of interest these days in "aacPlus" (aka. 
AAC-SBR) - a backwards-compatible variant of AAC audio that produces 
amazing audio quality, even at very low bitrates.  (FYI, this is the codec 
that's used by XM satellite radio.)  IMHO, a 32 kbps aacPlus stream sounds 
as good as a 128 kbps MP3 stream, and even an 8 kbps aacPlus stream sounds 
pretty good.  FYI, LIVE.COM now supports "aacPlus" encoding and decoding 
(in a licensed, closed-source implementation).

Of course, all of this is ignoring Microsoft, which is going to continue to 
try to use its monopoly position to try to get their "Windows Media" codecs 
and protocols adopted as the 'de facto' standard whereever possible.


	Ross Finlayson
	LIVE.COM
	<http://www.live.com/>