[Live-devel] 'Q' factor from JPEG file

[Ross Finlayson]

>I need to steam static JPEG files over RTP.
>I did read that mailing list and I have prepared all classes.
>There is just one thing which I don't understand now :(
>Is it possible to receive quality factor from JPEG file?

Unfortunately there's no way to directly get the Q factor from a JPEG 
image.  However, if the image is using standard quantization tables 
(if it's not using standard tables, then you won't be able to stream 
it), then you can usually figure out the Q factor 'by hand', by 
figuring out which value of the Q factor would produce the resulting 
quantization table values (see, for example, the code for 
"makeDefaultQtables()" in "liveMedia/JPEGVideoRTPSource.cpp".


	Ross Finlayson
	Live Networks, Inc. (LIVE555.COM)
	<http://www.live555.com/>