[Live-devel] video/JPEG streaming

PROMONET Michel michel.promonet at thalesgroup.com
Mon Feb 27 06:32:18 PST 2012


                Hi Ross,

I read severals times in the live555 mailing list and on your site that you seems to consider MJPEG streaming as something to avoid.
But in some situation (dedicated network, when it is needed to garanty precise positionning) it could be interesting.

Reading the RFC 2435 and the code of live555, it seems that what is missing is very things, so I tried to improve my understanding of live555 library.

I attached an class inherited from JPEGVideoSource interface that get RTP informations from the JPEG header as you suggest http://lists.live555.com/pipermail/live-devel/2003-November/000037.html
and a test program.

I did not really understood debate about qFactor that seems not extratable from the quantification table data.
Using  different precision for quantification table (0,8,255), and different qFactor (128,255) doesnot seems to have big impact on the displayed picture.
Using qFactor below 128, produce a image with very few contrast.

But perhaps the viewer is translating values before display ?
Do you have your own favourite figure for the qFactor ? or do I miss things in the RFC ?

Thanks for your advices.

Best Regards,

                Michel.

[@@THALES GROUP RESTRICTED@@]

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