Hello.<br><br>I work in Elphel, Inc (<a href="http://www3.elphel.com/index.php" target="_blank" onclick="return top.js.OpenExtLink(window,event,this)">http://www3.elphel.com/index.php</a>), we make high resolution network videocamera, what send videostream over RTP/RTSP in MJPEG and Theora format.
<br>I have question, about dynamic payload type for MJPEG in live555 library.<br><br>RTP
MJPEG RFC format with payload #26 have limitation for image size - each
size of image must be less than 2040 pixels, and larger size not
supported. In current live555 code exist hack for this limitation - if
width or height in MJPEG header == 0 - used 2048 size (what in general
not correct, but ok for 3MPx sensors with 2048x1536 image). We start
use 5MPx sensors, and get again this problem.
<br>In SDP parser (of live555 library) exist parser of field
"a=x-dimensions:WW,HH", but this data used only for container - not
when we restore JPEG headers from MJPEG packets; and also, in code, in
this time we can't get access to this properties
(MediaSubsession::videoWidth(), MediaSubsession::videoHeight() ) of
subsession from JPEG packet implementation class.
<br><br>I ask about add support for this in live555 - use width and
height from subsession description, when we make JPEG headers from
MJPEG (JPEG images have limit to 65526 pixels, not in 2040, so all must
be ok with JPEG headers).
<br><br>And also, if this feature possible - may be, in live555 can be
used for image size not only this extension ("a=x-dimensions:..."), but
attributes from SDP "a=fmtp: width=WW; height=HH" attributes, like in
drafts of RTP Theora, or RTP JPEG2000? In general, it's easy, if we can
get access to subsession description from JPEG header class.
<br clear="all"><span class="sg"><br></span><br>-- <br>With best regards, Spectr.