[opendtv] Re: Confusion about MPEG-4 AVC within MPEG-2 TS
- From: "Manfredi, Albert E" <albert.e.manfredi@xxxxxxxxxx>
- To: "OpenDTV (E-mail)" <opendtv@xxxxxxxxxxxxx>
- Date: Mon, 14 Feb 2005 13:39:17 -0500
Ron Economos wrote:
> But you need some kind if A/V wrapper to deal with
> audio, timestamps for A/V synchronization and
> timestamp clock recovery at the decoder. MPEG-2 TS
> provides all of those facilities and there is no
> (AFIK) usage based royalty fee. The multiplexer
> manufacturer takes care of any royalty fee (of
> course, indirectly passing on the cost to their
> customers).
Right you are. I neglected to include RTP/RTCP (Real
Time Protocol and Real Time Control Protocol) in
the stack of required protocols. This provides
the synchronization and resynchronization you
need, even in cases where a single stream is
generated out of multiple independent streams.
See RFCs 3550 and 3551.
Also, for many additional bells and whistles, e.g
as you might need for a complete VOD solution,
you can implement RTSP (Real Time Streaming
Protocol), RFC 2326. This gives the PAUSE and
PLAY and SETUP type of commands.
RTP/RTCP are designed specifically to work over
non-QoS guaranteed media, which is why they are
well suited to IPTV. Obviously, there's a limit
to how bad the underlying network can be.
However, Gary Hughes has a point, that in order to
reuse what was developed for cable, use of MPEG-2
TS might have its advantages even over an IPTV net.
Bert
----------------------------------------------------------------------
You can UNSUBSCRIBE from the OpenDTV list in two ways:
- Using the UNSUBSCRIBE command in your user configuration settings at
FreeLists.org
- By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word
unsubscribe in the subject line.
Other related posts:
