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

[Sassan Pejhan]

Another approach that is sometimes used for 
multicast sessions - where users may join in 
midstream - is to transmit the VOS/VO/VOL 
headers at regular intervals as part of the 
stream itself. This is useful in cases where 
SAP is not used.
Sassan
> -----Original Message-----
> From: Herbert Thoma [mailto:tma iis.fhg.de]
> Sent: Monday, February 28, 2024 4:18 AM
> To: Loren Rogers
> Cc: mp4-tech lists.mpegif.org
> Subject: Re: [Mp4-tech] MP4 encoder/decoder for live video conference
> vs.streaming
> 
> 
> 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
> > 
> > 
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-- 
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/
_______________________________________________
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