Questions tagged [sdp]

The Session Description Protocol (SDP) describes multimedia sessions for the purpose of session announcement, session invitation and other forms of multimedia session initiation.

Session directories assist the advertisement of conference sessions and communicate the relevant conference setup information to prospective participants. SDP is designed to convey such information to recipients. SDP is purely a format for session description - it does not incorporate a transport protocol, and is intended to use different transport protocols as appropriate including the Session Announcement Protocol (SAP) , Session Initiation Protocol (SIP) , Real-Time Streaming Protocol (RTSP) , electronic mail using the MIME extensions, and the Hypertext Transport Protocol (HTTP) .

Protocol Structure - SDP (Session Description Protocol)

SDP messages are text messages using the ISO 10646 character set in UTF-8 encoding. SDP Session description (optional fields has an *) is:

v= (protocol version)

o= (owner/creator and session identifier).

s= (session name)

i=* (session information)

u=* (URI of description)

e=* (email address)

p=* (phone number)

c=* (connection information - not required if included in all media)

b=* (bandwidth information)

One or more time descriptions (see below)

z=* (time zone adjustments)

k=* (encryption key)

a=* (zero or more session attribute lines)

Zero or more media descriptions (see below)

Time description

t= (time the session is active)

r=* (zero or more repeat times)

Media description

m= (media name and transport address)

i=* (media title)

c=* (connection information - optional if included at session-level)

b=* (bandwidth information)

k=* (encryption key)

a=* (zero or more media attribute lines)

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How to enable H264 on Android webRTC

How to enable H264 on Android WebRTC. PeerConnection to createOffer there was no h264 description in SDP.
fldy
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H264 profile-iop explained

Identify h264 profile and level from profile-level-id in sdp? How does one identify what the constraints actually mean? For example I have a profile-type-id: 42801e that translates to: How am I to relate that to the features defined in the table…
TheMeaningfulEngineer
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How to integrate SIP into Android?

How to implement SIP protocol in Android ? there is any SDK or library available to implement it easily into Android?
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How to set up SDP for High quality Opus audio

I have been trying to transmit some high quality audio stream through WebRTC. Opus, the main advertised codec seems perfect since it can support up to 510kbit/s, way more than needed. The problem is, setting up the Webrtc SDP is way less obvious…
Ben Banks
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Can I turn off SRTP when use webrtc

Now I test webrtc communicate with SIP Client(sx20) I send invite message with webrtc sdp. but sip client answer has not finger print, and sip client answer is not SRTP just RTP. So I need to turn off SRTP in WEBRTC. Can I do it? and one more…
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How can I watch my video from a sdp file?

I'm using ffmpeg to create a streaming. It works fine. I have a server and with ffplay I can watch my stream. My only (big) constraint is real time. I have to embed it into an HTML page accessible from mobile devices. I tried with HTML5 video tag…
Marco Peca
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Playing RTP using VLC

I currently have an Android application that is capturing video from the camera and streaming it over RTP. I do not use RTSP. I have created a SDP file that describes the RTP feed. I can open the SDP file in Quicktime 7 and can see the stream,…
lucasweb
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How to use libsrtp or similar library to decrypt/encrypt the WebRTC data stream?

I have a server which receives OFFER, ANSWER, CANDIDATE-s from web browser for a WebRTC session and passes to its peer. Later the data is also passed from the same server. Now to implement our own SFU-like mechanism, I was considering, if this data…
iammilind
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Chrome Android not using all codec options in SDP offer

When I run RTCRtpSender.getCapabilities("video").codecs; on Chrome Android it includes H264. However, I run var offer = RTCPeerConnection.createOffer() and look at offer.sdp it will only sometimes include H264 in the offer. This is causing me issues…
Andrew
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Should WebRTC's SDP be private for secure communication?

There are ice-ufrag and ice-pwd parameters in SDP, but do they (or any other parameters) really need be private for secure end-to-end connection if I can ensure SDP offer/answer was not modified (with digital signature as an example)? The use case…
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Failed to set remote answer sdp: Failed to push down transport description: Failed to set SSL role for the channel

I'm using webRTC to build a system which supports audio calls. Here's how it works: - User A createOffer, then setLocalDescription with the offer - User B receiveOffer, then setRemoteDescription with the offer - User B createAnswer, then…
sonlexqt
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WebRTC 'goog-remb' and 'transport-cc' SDP lines

I would like to know what are the meaning of this SDP lines as I am trying to get the smoothest framerate posible with 5% to 10% packet losses. The lines i don´t know are: a=rtcp-fb:100 goog-remb a=rtcp-fb:100 transport-cc I don´t know why firefox…
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Freeswitch. Error 487 Role Conflict (on REINVITE)

I'm trying to add video track to stream and then call renegotiate() from JsSip. However, when I'm doing it from caller it works fine, but when I'm doing it from callee it's not working (session terminating). I looked into the Freeswitch logs and…
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Diagnosing WebRTC ICE Failures

For the last three years, whenever I use WebRTC, somewhere or other I will be dogged by the following error: ICE Failed, see about:webrtc for more details The error seems to have pop up in a variety of places: If the network is turned off for…
Laef
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Play a SDP file with VLC?

Goal Confirming that VLC can play a stream from a locally given SDP file. This appears to be possible based on testimonies: Playing RTP using VLC - Stack Overflow How to send SDP over RTP - Stack Overflow Experiment So I looked for a publicly…
Stéphane Gourichon
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