[Live-devel] Monochromatic MJPEG stream

[Ross Finlayson]

>I'm working with guys at Elphel to enable RTP streaming of their raw
>format (called JP4). The JP4 format is stored as MJPEG file with
>single component JPEG frames. Elphel uses a custom RTP server, but the
>client (mplayer) uses live55 library and without single component
>support, all decoded JPEG frames get wrong headers.
>
>Per RFC 2435, only three component JPEG files have a defined 'type' on
>the RTP/MJPEG packet header.
>
>I was wondering if a patch to support single component JPEGs on
>live555 would be accepted, using a non standard 'type' field (type >
>127),
>
>Another possibility is to use a x-* field on the SDP file, as used to
>support frame dimensions larger than 2048.

Paulo,

Note that we have already (in December 2007) added the patch that 
Andrey Filippov described here: 
http://lists.live555.com/pipermail/live-devel/2007-November/007760.html 
This patch allows the server to specify the JPEG width and height in 
the SDP description, using the "a=x-dimensions:<width>,<height>". 
(These will then be used if the 'width' and 'height' fields in the 
JPEG header are 0.)

If that's not sufficient for your needs, and you instead (or also) 
want to use a non-standard JPEG type field, then this would 
constitute an extension (albeit a backwards-compatible one) to the 
RFC 2435 RTP payload format.  In that case, you should contact the 
IETF's AVT working group (avt at ietf.org), outlining your problem, and 
your proposed solution.  If the AVT working group adopts your 
proposed solution (this might require that you write an Internet 
Draft that describes it), then I would be happy to add a patch to our 
code to support it.
-- 

Ross Finlayson
Live Networks, Inc.
http://www.live555.com/