[AG-TECH] JPEGVideoService

[Andrew Rowley]

Hi,

I just want to reiterate that the vic JPEG video service is NOT compatible
with ScreenStreamer.  Using ScreenStreamer to transmit the screen on the
same multicast address and port as JPEG vic will in all probability crash
JPEG vic.

For anyone who is interested, it would appear that this is a bug in the JPEG
codec in vic - this does not seem to handle the case where the JPEG packets
are split in a certain way.  The alternative is that the JPEG codec in JMF
does not split the packets correctly.  However, ScreenStreamer can handle
any sending by JPEG vic so I would guess that it is the JPEG vic decoding
that is broken to some extent.  If anyone knows why this might be happening,
I would like to know what the problem is.  The workaround is that you need
to set ScreenStreamer up to minimise the splitting of the packets e.g. set
the quality low and reduce the size of the sending transmission, or of
course just use ScreenStreamer at both ends using a different multicast
address and port.

Andrew :)

============================================
Access Grid Support Centre,
RSS Group,
Manchester Computing,
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Manchester, 
M13 9PL, 
UK
Tel: +44(0)161-275 0685
Email: Andrew.Rowley at manchester.ac.uk 

> -----Original Message-----
> From: owner-ag-tech at mcs.anl.gov [mailto:owner-ag-tech at mcs.anl.gov] On
> Behalf Of Christoph Willing
> Sent: 02 June 2005 23:55
> To: AG-TECH list
> Subject: [AG-TECH] JPEGVideoService
> 
> A JPEG video AG node service is now available via the wiki:
> 	http://www-unix.mcs.anl.gov/fl/research/accessgrid/wiki/moin.cgi/
> ContributedSoftware
> 
> It enables enables PAL & NTSC size video streams (at a quality
> dependent on capacity of the encoding machine) and does not interfere
> with the default H.261 video, since it uses a different multicast
> address. Configuration is exactly the same as for normal H.261 video,
> via VenueClient's "Manage My Node" menu.
> 
> 
> chris
> 
> 
> Christoph Willing                        Ph: +61 7 3365 8350
> QPSF Access Grid Manager
> University of Queensland
>