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<pre wrap="">I have to deal with application-specific SDP attributes (a=my_attribute:value). I have my own subclass of MediaSubsession.
I was wondering if parsing of subsession description lines (c=, b=, a=rtpmap... ) could be done in a virtual new method (ie MediaSubsession::parseSDPline()) that could be overloaded, instead of being hardcoded in MediaSession::initializeWithSDP().
What do you think ?
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<pre wrap="">This is a possibility, but I consider changes like this - whose sole purpose is to support non-standard protocol extensions - to be low priority.
What 'application-specific SDP attributes' do you have in mind?
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We are targetting professional live audio for studio. For precise
sync and low delay we have to carry information giving the relation
between RTP timestamp and PTP timestamp (NTP timestamp carried in
RTCP is not precise enough). I'll will not give details here, but we
retrieve this constant delta through a new SDP "a=timesync:value"
media-level attribute. It is a legal extension to the standard, not
yet published. <br>
<br>
You can also think to other extensions, like "a=orient:portrait" and
the ones given in Section 6 of RFC456, or "a=cliprect:..."
(Quicktime) or "a=crypto" (for RTP/SAVP RFC4568), or de-facto
standard extensions, like "a=x-dimensions" that you've chosen to
implement...<br>
<br>
Ideally, it would be cumfortable to be able to extend "Media Level"
and "Session Level" attributes through virtual methods.<br>
<br>
Best wishes<br>
<br>
E. HEURTEL<br>
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