SDP

Presenters : Sithideth Viengkhou - Embrionix

Year : 2019

dlp_document_download : Presentation on SDP for IP showcase By Sithideth Viengkhou April 2019 49 -153 -162 125 -43 -138 203 -34 -41 226 -154 -48 212 -195 -59 139 -189 -79 38 -38 -38 51 -51 -51 239 -239 -239 145 -206 -244 30 -113 -184 51 -163 -87 22 -22 -22 248 -248 -248 255 -255 -255 Embrionix colors Secondary colors Background colors What is SDP? + The Session Description Protocol is a format for describing streaming media parameters. It doesn't deliver any media, but rather helps tie end points together. It is extensible to new media types. + It consists of a number of lines of text in the form: + <type>=<value> 2 49 -153 -162 125 -43 -138 203 -34 -41 226 -154 -48 212 -195 -59 139 -189 -79 38 -38 -38 51 -51 -51 239 -239 -239 145 -206 -244 30 -113 -184 51 -163 -87 22 -22 -22 248 -248 -248 255 -255 -255 Embrionix colors Secondary colors Background colors What is SDP?: Overview + There are several sections in a SDP session description: + Session Level: + Starts with a "v=" and ends at the first media -level section + Contains information such as: + v= (protocol version) + o= (originator and session identifier) + s= (session name) + Media Level: + Starts with a "m'=" to the next media -level section. + Contains information such as: + m= (media name and transport address) + i=* (media title) + c=* (connection information ---- optional if included at session level) + a=* (zero or more media attribute lines) Proprietary and confidential information, Copyright Embrionix 2019 3 49 -153 -162 125 -43 -138 203 -34 -41 226 -154 -48 212 -195 -59 139 -189 -79 38 -38 -38 51 -51 -51 239 -239 -239 145 -206 -244 30 -113 -184 51 -163 -87 22 -22 -22 248 -248 -248 255 -255 -255 Embrionix colors Secondary colors Background colors What is SDP?: Overview + There is also the Time description "section" + t= (time the session is active). In our application it is almost always 0 + r=* (zero or more repeat times) Proprietary and confidential information, Copyright Embrionix 2019 4 49 -153 -162 125 -43 -138 203 -34 -41 226 -154 -48 212 -195 -59 139 -189 -79 38 -38 -38 51 -51 -51 239 -239 -239 145 -206 -244 30 -113 -184 51 -163 -87 22 -22 -22 248 -248 -248 255 -255 -255 Embrionix colors Secondary colors Background colors Important Lines + Origin ("o="): Give the originator of the session, who is sending the media + Connection Data ("c="): Contains the connection data; base IP Address/ ttl + Media Description ("m="): Tell if the media is Audio, Video or text and which port port is the media streamed and transport protocol. + Attribute ("a="): ST2110 use a few different attributes. + a= rtpmap : Is the attribute for the dynamic payload + a= fmtp : Is the attribute for the media format, such as Video format, exact frame rate, colorimetry. + a= ts -refclk : is the reference clock Proprietary and confidential information, Copyright Embrionix 2019 5 49 -153 -162 125 -43 -138 203 -34 -41 226 -154 -48 212 -195 -59 139 -189 -79 38 -38 -38 51 -51 -51 239 -239 -239 145 -206 -244 30 -113 -184 51 -163 -87 22 -22 -22 248 -248 -248 255 -255 -255 Embrionix colors Secondary colors Background colors Simple Yet Effective + With a single SDP text, we can describe a single 1080i video stream that a camera generates Proprietary and confidential information, Copyright Embrionix 2019 6 s=st2110 0 -0-0 t=0 0 m=video 20000 RTP/AVP 96 c=IN IP4 239.20.37.1/64 a=source -filter: incl IN IP4 239.20.37.1 192.168.39.37 a=rtpmap:96 raw/90000 a=fmtp:96 sampling=YCbCr -4:2:2; width=1920; height=1080; exactframerate =60000/1001; depth=10; TCS=SDR; colorimetry=BT709; PM=2110GPM; SSN=ST2110 -20:2017; TP=2110TPN; interlace; a= mediaclk:direct =0 a= ts -refclk:ptp =IEEE1588 -2008:08 -00 -11 -ff -fe -22 -91 -bb:0 49 -153 -162 125 -43 -138 203 -34 -41 226 -154 -48 212 -195 -59 139 -189 -79 38 -38 -38 51 -51 -51 239 -239 -239 145 -206 -244 30 -113 -184 51 -163 -87 22 -22 -22 248 -248 -248 255 -255 -255 Embrionix colors Secondary colors Background colors It Can Describe A Quad Stream That Composes A 12G Video Proprietary and confidential information, Copyright Embrionix 2019 7 Simply add "a=group" And "a=mid:" 49 -153 -162 125 -43 -138 203 -34 -41 226 -154 -48 212 -195 -59 139 -189 -79 38 -38 -38 51 -51 -51 239 -239 -239 145 -206 -244 30 -113 -184 51 -163 -87 22 -22 -22 248 -248 -248 255 -255 -255 Embrionix colors Secondary colors Background colors Simple Mechanics: Connecting A Sender To A Receiver + This is a real, simplistic example that doesn’t take into account all the work in IS04/05 or other protocols that use SDP such as EMBER + Proprietary and confidential information, Copyright Embrionix 2019 8 49 -153 -162 125 -43 -138 203 -34 -41 226 -154 -48 212 -195 -59 139 -189 -79 38 -38 -38 51 -51 -51 239 -239 -239 145 -206 -244 30 -113 -184 51 -163 -87 22 -22 -22 248 -248 -248 255 -255 -255 Embrionix colors Secondary colors Background colors IP System Boot Up & Exchange Of SDP Files STAGE 1 : Power Up Proprietary and confidential information, Copyright Embrionix 2019 9 Sender 1 Sender 2 Control System Receivers At boot up. SDP files table = empty in Control System Senders Receiver 1 49 -153 -162 125 -43 -138 203 -34 -41 226 -154 -48 212 -195 -59 139 -189 -79 38 -38 -38 51 -51 -51 239 -239 -239 145 -206 -244 30 -113 -184 51 -163 -87 22 -22 -22 248 -248 -248 255 -255 -255 Embrionix colors Secondary colors Background colors IP System Boot Up & Exchange Of SDP Files STAGE 2 : Fetching SDP Proprietary and confidential information, Copyright Embrionix 2019 10 Sender 1 Sender 2 Control System Receivers Control system Fetch the SDP files from Senders Senders 1 2 Get_SDP Get_SDP Send_SDP Send_SDP Send_SDP Send_SDP Let’s assume the user wants to display Video from Camera and Audio from emSFP Receiver 1 49 -153 -162 125 -43 -138 203 -34 -41 226 -154 -48 212 -195 -59 139 -189 -79 38 -38 -38 51 -51 -51 239 -239 -239 145 -206 -244 30 -113 -184 51 -163 -87 22 -22 -22 248 -248 -248 255 -255 -255 Embrionix colors Secondary colors Background colors IP System Boot Up & Exchange Of SDP Files STAGE 2 : Fetching SDP Proprietary and confidential information, Copyright Embrionix 2019 11 Sender 1 Sender 2 Control System Receivers Control system Fetch the SDP files from Senders Senders 1 2 Get_SDP Get_SDP Send_SDP Send_SDP Send_SDP Send_SDP Let’s assume the user wants to display Video from Camera and Audio from emSFP Receiver 1 49 -153 -162 125 -43 -138 203 -34 -41 226 -154 -48 212 -195 -59 139 -189 -79 38 -38 -38 51 -51 -51 239 -239 -239 145 -206 -244 30 -113 -184 51 -163 -87 22 -22 -22 248 -248 -248 255 -255 -255 Embrionix colors Secondary colors Background colors The Receiver Needs to Get the correct SDP information IP System Boot Up & Exchange Of SDP Files STAGE 3 : Configuring Receiver Proprietary and confidential information, Copyright Embrionix 2019 12 Sender 1 Sender 2 Receiver 1 Control System Receivers Senders 1 2 Set Multicast IP Video and audio 49 -153 -162 125 -43 -138 203 -34 -41 226 -154 -48 212 -195 -59 139 -189 -79 38 -38 -38 51 -51 -51 239 -239 -239 145 -206 -244 30 -113 -184 51 -163 -87 22 -22 -22 248 -248 -248 255 -255 -255 Embrionix colors Secondary colors Background colors Simply push the sender SDP to the receiver. IP System Boot Up & Exchange Of SDP Files STAGE 3 : Configuring Receiver Proprietary and confidential information, Copyright Embrionix 2019 13 Sender 1 Sender 2 Receiver 1 Control System Receivers Senders 1 2 Set Multicast IP Video and audio 49 -153 -162 125 -43 -138 203 -34 -41 226 -154 -48 212 -195 -59 139 -189 -79 38 -38 -38 51 -51 -51 239 -239 -239 145 -206 -244 30 -113 -184 51 -163 -87 22 -22 -22 248 -248 -248 255 -255 -255 Embrionix colors Secondary colors Background colors IP System Boot Up & Exchange Of SDP Files STAGE 4 : Push SDP in Receiver Proprietary and confidential information, Copyright Embrionix 2019 14 Sender 1 Sender 2 Receiver 1 Control System Receivers Senders 1 2 Send SDP Video and Audio 1 ALL DONE 49 -153 -162 125 -43 -138 203 -34 -41 226 -154 -48 212 -195 -59 139 -189 -79 38 -38 -38 51 -51 -51 239 -239 -239 145 -206 -244 30 -113 -184 51 -163 -87 22 -22 -22 248 -248 -248 255 -255 -255 Embrionix colors Secondary colors Background colors Potential Improvements + What if for a small installation, the media stream would be self descriptive with the SDP being a companion stream such as SAP (Session Announcement Protocol). Where the SDP of the streamed media is periodically streamed by the Sender. So any change in media stream, such as format change will also send to listening receiver(s). Proprietary and confidential information, Copyright Embrionix 2019 15 Thanks!