[M4IF Technotes] Use Rtp to transport Mpeg4 video

[Dave Singer]

Li -- You have it upside-down.  One would only use the (ugly) 
in-stream timing of MPEG-4 video when the external system does not. 
In this case, in order to achieve sync, and obey the general nature 
of RTP, one would believe the RTP time-stamps and ignore what is 
in-stream.  The same goes for an MP4 file.
The config information in RTP is normally carried out of band, in 
SDP, just as it is in MP4.
In summary, the timestamp of a vop in RTP is determined by the RTP 
timestamp;  vop_time_increment, modulo-time-base, and all that stuff, 
are irrelevant.
At 07:00 +0200 7/3/03, Hans-Juergen Bardenhagen wrote:
>On Thursday, 03.07.03, 09:14 (received 03.07.03, 06:49) Li wrote:
>
>>  Now I'm trying to transport Mpeg4 video stream over RTP, and coming
>>  against a problem. The RTP says that the configuration information,
>>  such as Visual Object Sequence Header and other headers, should be
>>  bond into a rtp packet. Then How to determine the time stamp of such
>>  a rtp packet? The time stamp of the rtp packet consisting of a vop
>>  can be easily determined by inspecting its vop-time-increment syntax.
>
>As far as I know, the elementary streams in a MP4 container must be 
>"hinted" for this, i.e. creating individual time stamp tracks that are 
>added to the the container. At least this is how the open source MPEG4IP 
>project handles RTP streaming e.g. with Apple's Darwin Streaming Server 
>(DSS). See http://sourceforge.net/projects/mpeg4ip/ for more, they also 
>have a web forum which you can search through and ask Bill May from 
>Cisco if you need further information.
>
>ZZee ya, Hans-Jürgen
>
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-- 
David Singer
Apple Computer/QuickTime