[Mp4-tech] MP4 encoder/decoder for live video conference vs. streaming

[Herbert Thoma]

Hi Loren,
usually the VS, VO and VOL headers are transmitted in the startup
phase of the connection. These headers are typically transmitted
over a reliable channel (e.g. RTSP on TCP in ISMA streaming)
whereas the VOPs are transmitted over a unreliable channel
(eg. RTP on UDP in ISMA streaming).
  Herbert.
Loren Rogers schrieb:
> Hello,
> 
> How does one get around the problems of transporting MPEG4-2 video 
> streams for live video conferencing vs. streaming.  The reason I’m 
> asking is because there is information that is left out of the VOP and 
> VOP header, like frame size (QCIF, CIF, etc…).  I’m not sure what’s 
> normally done for live video conferencing.  Whether the VOL, or VO, or 
> both pieces of information is sent just once in the beginning of the 
> call, or for every single VOP.  Can someone please advise.
> 
> Thanks.
> 
> /Loren
> 
> 
> _______________________________________________
> NOTE: Please use clear subject lines for your posts. Include [audio, 
> [video], [systems], [general] or another apppropriate identifier to 
> indicate the type of question you have.
> 
> Note: Conduct on the mailing list is subject to the Antitrust guidelines 
> found at 
> http://www.mpegif.org/public/documents/vault/mp-out-30042-Antitrust.php
> 

-- 
Herbert Thoma
Group Manager Video
Multimedia Realtime Systems Department
Fraunhofer IIS
Am Wolfsmantel 33, 91058 Erlangen, Germany
Phone: +49-9131-776-323
Fax:   +49-9131-776-399
email: tma iis.fhg.de
www: http://www.iis.fhg.de/