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Realtime stream information can be obtained using STOMP protocol over Websocket API.
STOMP client connection over Websocket to backend server
To connect to backend server for obtaining realtime metric values, do the following:
1. Establish Secure Websocket connection to https://hostname:8090/ws, where hostname is backend server address
2. Establish STOMP connection by sending the message
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CONNECT
accept-version:1.2
host:hostname
^@ |
3.Establish Websocket API connection
2. Subscribe to /stream/nodeId/mediaId event by sending the message
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SUBSCRIBE id:sub-12 destination:/stream/153/010934f0ca77c700-07668e86-11e9-a9508386-59983a9de3c8dbc3d191a79a ^@ |
Where
- 15 3 - node identifier in backend database
- 010934f0ca77c700-07668e86-11e9-a9508386-59983a9de3c8 dbc3d191a79a - stream media session identifier
4. Subscribe to /alarm event for receiving alarms
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SUBSCRIBE
id:sub-0
destination:/alarm
^@ |
After that, client starts receiving STOMP messages in plain text
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"MESSAGE\ndestination destination:/stream/153/010934f0ca77c700-07668e86-11e9-a950-59983a9de3c8\ncontent8386-dbc3d191a79a content-type:application/json;charset=UTF-8\nsubscription subscription:sub-1\nmessage2 message-id:oilwo0os-701\ncontent3-50 content-length:1349\n\n1339 [{\"VIDEO_SYNC\":37546371251971560504547907,\"VIDEO_CODEC\":120119,\"VIDEO_NACK\":180,\"VIDEO_PLI\":0,\"VIDEO_RATE\":478104571616,\"VIDEO_WIDTH\":320,\"VIDEO_HEIGHT\":240,\"VIDEO_FPS\":30,\"timestamp\":15456483255061560504547917},{\"AUDIO_SYNC\":37546371252271560504547890,\"AUDIO_CODEC\":111,\"AUDIO_RATE\":3261626664,\"timestamp\":15456483255581560504547923,\"AUDIO_LOST\":210},{\"AUDIO_SYNC\":37546371253471560504548010,\"AUDIO_CODEC\":111,\"AUDIO_RATE\":3296027040,\"timestamp\":15456483256841560504548040,\"AUDIO_LOST\":210},{\"VIDEO_SYNC\":37546371253971560504548099,\"VIDEO_CODEC\":120119,\"VIDEO_NACK\":180,\"VIDEO_PLI\":0,\"VIDEO_RATE\":504632577416,\"VIDEO_WIDTH\":320,\"VIDEO_HEIGHT\":240,\"VIDEO_FPS\":3130,\"timestamp\":15456483257011560504548119},{\"AUDIO_SYNC\":37546371254671560504548130,\"AUDIO_CODEC\":111,\"AUDIO_RATE\":3304826624,\"timestamp\":15456483258051560504548167,\"AUDIO_LOST\":210},{\"VIDEOAUDIO_SYNC\":37546371255971560504548250,\"VIDEOAUDIO_CODEC\":120111,\"VIDEO_NACK\AUDIO_RATE":27976,"timestamp":181560504548282,\"VIDEOAUDIO_PLI\LOST":0},\{"VIDEO_RATE\SYNC":4956241560504548307,\"VIDEO_WIDTH\CODEC":320119,\"VIDEO_HEIGHT\NACK":2400,\"VIDEO_FPS\PLI":300,\"timestamp\VIDEO_RATE":1545648325911}581968,{\"AUDIOVIDEO_SYNC\WIDTH":3754637125587320,\"AUDIOVIDEO_CODEC\HEIGHT":111240,\"AUDIOVIDEO_RATE\FPS":3304831,\"timestamp\":1545648325921,\"AUDIO_LOST\":211560504548318},{\"AUDIO_SYNC\":37546371257071560504548370,\"AUDIO_CODEC\":111,\"AUDIO_RATE\":3240028128,\"timestamp\":15456483260491560504548404,\"AUDIO_LOST\":210},{\"VIDEO_SYNC\":37546371257961560504548499,\"VIDEO_CODEC\":120119,\"VIDEO_NACK\":180,\"VIDEO_PLI\":0,\"VIDEO_RATE\":480224583032,\"VIDEO_WIDTH\":320,\"VIDEO_HEIGHT\":240,\"VIDEO_FPS\":3231,\"timestamp\":15456483261041560504548506},{\"AUDIO_SYNC\":37546371258271560504548490,\"AUDIO_CODEC\":111,\"AUDIO_RATE\":3304829568,\"timestamp\":15456483261591560504548522,\"AUDIO_LOST\":210}]\u0000" |
or in JSON using STOMP.js library
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{ "command": "MESSAGE", "headers": { "content-length": "12821339", "message-id": "oilwo0os3-92650", "subscription": "sub-12", "content-type": "application/json;charset=UTF-8", "destination": "/stream/153/010934f0ca77c700-07668e86-11e9-a9508386-59983a9de3c8dbc3d191a79a" }, "body": [ { { "VIDEO_SYNC": 1560504547907, "VIDEO_CODEC": 119, "VIDEO_NACK": 0, "VIDEO_PLI": 0, "VIDEO_RATE": 571616, "VIDEO_WIDTH": 320, "VIDEO_HEIGHT": 240, "VIDEO_FPS": 30, "timestamp": 1560504547917 }, { "AUDIO_SYNC": 1560504547890, "AUDIO_CODEC": 111, "AUDIO_RATE": 26664, "timestamp": 1560504547923, "AUDIO_LOST": 0 }, { "AUDIO_SYNC": 1560504548010, "AUDIO_CODEC": 111, "AUDIO_RATE": 27040, "timestamp": 1560504548040, "AUDIO_LOST": 0 }, { "VIDEO_SYNC": 1560504548099, "VIDEO_CODEC": 119, "VIDEO_NACK": 0, "VIDEO_PLI": 0, "VIDEO_RATE": 577416, "VIDEO_WIDTH": 320, "VIDEO_HEIGHT": 240, "VIDEO_FPS": 30, "timestamp": 1560504548119 }, { "AUDIO_SYNC": 1560504548130, "AUDIO_CODEC": 111, "AUDIO_RATE": 26624, "timestamp": 1560504548167, "AUDIO_LOST": 0 }, { "AUDIO_SYNC": 1560504548250, "AUDIO_CODEC": 111, "AUDIO_RATE": 27976, "timestamp": 1560504548282, "AUDIO_LOST": 0 }, { "VIDEO_SYNC": 37546372991701560504548307, "VIDEO_CODEC": 120119, "VIDEO_NACK": 200, "VIDEO_PLI": 0, "VIDEO_RATE": 617024581968, "VIDEO_WIDTH": 320, "VIDEO_HEIGHT": 240, "VIDEO_FPS": 2431, "timestamp": 1545648499723 1560504548318 }, { "AUDIO_SYNC": 37546372994821560504548370, "AUDIO_CODEC": 111, "AUDIO_RATE": 3060028128, "timestamp": 15456484997991560504548404, "AUDIO_LOST": 0 }, { "VIDEO_SYNC": 1560504548499, "VIDEO_CODEC": 119, "VIDEO_NACK": 0, "VIDEO_PLI": 0, "VIDEO_RATE": 583032, "VIDEO_WIDTH": 23 }, ... 320, "VIDEO_HEIGHT": 240, "VIDEO_FPS": 31, "timestamp": 1560504548506 }, { "AUDIO_SYNC": 1560504548490, "AUDIO_CODEC": 111, "AUDIO_RATE": 29568, "timestamp": 1560504548522, "AUDIO_LOST": 0 } ] } |
The messages contain metric values acquired from the node where the stream is published or played.
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UNSUBSCRIBE id:/stream/15/010934f0-0766-11e9-a950-59983a9de3c8sub-2 ^@ |
Connection setup
Maximum metrics count in one STOMP message is set with the following parameter in wcsoam.properties
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https://hostname:8090/api/profile/create { "name": "profile1", "rate": "30", "metrics": ["12"], "rules": ["1"] } |
and maximum metrics count 1 per one message
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https://hostname:8090/api/profile/update { "id": "2", "name": "profile1", "rate": "600", "metrics": ["12"], "rules": ["1"] } |
the messages will be send to subscriber near 1 per 20 seconds.
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https://hostname:8090/api/profile/update { "id": "2", "name": "profile1", "rate": "600", "metrics": ["12","23","89","1213"], "rules": ["1"] } |
the messages will be send to subscriber near 1 per 5 seconds.
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https://hostname:8090/api/profile/create { "name": "profile2", "rate": "30", "metrics": ["34","1011"], "rules": ["1"] } |
and maximum metrics count 1 per one message
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