[sip protocol] 来研究下rtpmap和fmtp等等东东吧
 |
dracularking
2008-12-19
sdp里牵涉到的概念，只有非常模糊的印象，还来不及细细研究，摆出来大家一起看看，有空一点点补全
|
|
dracularking
2008-12-19
初步的概念是它们是MediaDescriptions中的某一个MediaDescriptionImpl的AttibuteField 还有ptime,inactive,sendrecv,sendonly等
|
|
dracularking
2008-12-22
m=<media> <port>/<number of ports> <proto> <fmt> ...
这是 "m=" line的格式 其中的proto(protocol)比较常见的有 RTP/AVP: denotes RTP [19] used under the RTP Profile for Audio and Video Conferences with Minimal Control [20] running over UDP. |
|
dracularking
2008-12-26
RTP/AVP = RTP Audio/Video profile
a=rtpmap:<payload type> <encoding name>/<clock rate> [/<encoding parameters>] This attribute maps from an RTP payload type number (as used in an "m=" line) to an encoding name denoting the payload format to be used. It also provides information on the clock rate and encoding parameters. It is a media-level attribute that is not dependent on charset. |
|
dracularking
2008-12-26
a=fmtp:<format> <format specific parameters>
This attribute allows parameters that are specific to a particular format to be conveyed in a way that SDP does not have to understand them. The format must be one of the formats specified for the media. Format-specific parameters may be any set of parameters required to be conveyed by SDP and given unchanged to the media tool that will use this format. At most one instance of this attribute is allowed for each format. It is a media-level attribute, and it is not dependent on charset. |
