Subject: RE: Updated I/D for MPEG-4 Audio/Visual RTP payload format

From: "Y. Matsui" <[email-masked]>
Date: Wed, 28 Jun 2000 11:58:49 +0900

Dear Christine,

I would like to comment on your first question.

>1-  I understood from earlier e-mail/MPEG4-IETF phone
>meeting discussions that to be MPEG-4 compliant,
>terminals would have to support the sync layer, because
>the ESI is not normative.

MPEG-4 system is not mandatory if the underlying
transmux provides the functionality such as synchronization,
multiplexing, identification, etc.,   RTP and underlying UDP/IP
layer provides them.

Another example is ISO/IEC 13818-1 AMD 7, MPEG-4
on MPEG-2 Systems.  It has been standardized based on the
same concept.  This amendment allows to map MPEG-4
AV streams directory into MPEG-2 TS or PS packets in 
normative way.

>Therefore, what would be the status of
>the current draft with respect to MPEG-4 compliance
>issues, since it says:
>
>"These RTP payload formats enable to carry MPEG-4
>Audio/Visual streams without using the synchronization
>and stream management functionality of MPEG-4 Systems
>[6]. Such RTP payload format would be used within systems
>where their own stream management functionality is provided
>and thus such functionality in MPEG-4 Systems is not necessary.
>H.323 terminals are an example of such systems. MPEG-4
>Audio/Visual streams are not managed by
>MPEG-4 Systems Object Descriptors  but by H.245. The streams
>are directly mapped onto RTP packets without using the
>synchronization functionality of MPEG-4 Systems."

Best regards,
Yoshinori Matsui
Matsushita / Panasonic

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From: Leonid Rosenboim <[email-masked]>
Date: Wed, 28 Jun 2000 11:05:03 +0200

Just a quick (potentially unrelated) question:

Are you aware of anyone actually using the apparently normative MPEG-4
transport
which maps MPEG-4 ES on top of MPEG-2 TS wich in turn is carried over
UDP/IP ?