[opendtv] Re: ASF for VC1

  • From: "Gary Hughes" <ghughes@xxxxxxxxxxxx>
  • To: <opendtv@xxxxxxxxxxxxx>, "WMTalk" <WMTalk@xxxxxxxxxxxxxxxxxxxxx>
  • Date: Wed, 18 May 2005 17:30:02 -0400

> -----Original Message-----
> From: opendtv-bounce@xxxxxxxxxxxxx=20
> [mailto:opendtv-bounce@xxxxxxxxxxxxx] On Behalf Of Prashant Desai
> Sent: Wednesday, May 18, 2005 5:11 PM
> To: opendtv@xxxxxxxxxxxxx; 'WMTalk'
> Subject: [opendtv] ASF for VC1
> Does the Micosoft's ASF container format have also been=20
> standardized by SMPTE while standardizing VC1 [ wmv9 ] ?=20
> =20
> Or all the VC1 products have to use MPEG2 TS ?  I am having=20
> this doubt coz while checking out on various encoders for vc1 / wm9=20
> The o/p card/module is optional and can be  in IP Ethernet=20
> ASF or  can be ASI MPEG2 TS ? =20
SMPTE 421M is meant to be transport independent. I've been told that
the changes between WMV9 and VC1/WMV9.5 were primarily to address the
need for a clean separation between transport and video payload.=20

SMPTE RP227 will address the mapping of VC1 access units into MPEG-2
transport streams. It is an adjunct to the standard, but not part of it.
> =20
> So , is it because SMPTE standards of VC1 says that wmv9=20
> video must be within MPEG2 TS only ?=20
> =20
> The only concern is .. say if someone deploys  low end WM9=20
> based solution from Microsoft today , will he be able to migrate to=20
> High end telco grade VC1 based solution later on ?   that too=20
> without much
> of an hassle since  VC1 and wmv9 is exactly same ?  assuming=20
> that audio codec would remain the same After migration ?=20
I would not make that assumption. I do not know the details of the
transport used by WM9 servers.


Gary Hughes
Director of Media Engineering
Broadbus Technologies, Inc.
v: 978 264 7919
f: 978 264 9108

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