Stream parameters monitoring with REST API¶

Overview¶

WCS supports realtime stream publishing and playing parameters monitoring with REST API

Metrics available¶

Metric	Description
VIDEO_HEIGHT	Video height
VIDEO_WIDTH	Video width
VIDEO_RATE	Video bitrate
VIDEO_SYNC	Video synchronization
VIDEO_FPS	Video frame rate per second
VIDEO_NACK	NACK requests count
VIDEO_PLI	PLI packets count
VIDEO_CODEC	Video codec
VIDEO_K_FRAMES	Video key frames (I-frames) count
VIDEO_P_FRAMES	Video P frames count
VIDEO_B_FRAMES	Video B frames count
VIDEO_GOP_SIZE	Last group of frames size between keyframes
VIDEO_LOST	Video lost packets count
AUDIO_SYNC	Audio synchronization
AUDIO_RATE	Audio bitrate
AUDIO_LOST	Lost audio packets count
AUDIO_CODEC	Audio codec

Receiving common stream information¶

The /stream/find REST API query allows to find a stream by filter and get common information about streams found. Since build 5.2.923 stream metrics may also be requested.

REST query should be HTTP/HTTPS POST request as follows:

HTTP: http://streaming.flashphoner.com:8081/rest-api/stream/find
HTTPS: https://streaming.flashphoner.com:8444/rest-api/stream/find

Where

streaming.flashphoner.com - WCS server address
8081 - REST / HTTP port of WCS server
8444 - HTTPS port of WCS server
rest-api - URL mandatory part
/stream/find - REST query used

REST queries and responses¶

/stream/find¶

Find a stream and display its current information

Request example¶

POST /rest-api/stream/find HTTP/1.1
Host: localhost:8081
Content-Type: application/json

{
   "name":"stream1",
   "published":true,
   "display":["metrics"]
}

Response example¶

HTTP/1.1 200 OK
Access-Control-Allow-Origin: *
Content-Type: application/json

[
  {
    "appKey": "flashStreamingApp",
    "sessionId": "/192.168.23.83:51309/192.168.130.39:1935",
    "mediaSessionId": "6af0baf1-f014-48d6-b285-c975951a402f",
    "name": "stream1",
    "published": true,
    "hasVideo": true,
    "hasAudio": true,
    "status": "PUBLISHING",
    "sdp": ...,
    "audioCodec": "mpeg4-generic/48000/2",
    "videoCodec": "H264",
    "record": false,
    "width": 640,
    "height": 360,
    "bitrate": 0,
    "minBitrate": 0,
    "maxBitrate": 0,
    "quality": 0,
    "history": false,
    "gop": 0,
    "fps": 0,
    "audioBitrate": 0,
    "codecImpl": "",
    "transport": "UDP",
    "cvoExtension": false,
    "createDate": 1616730493789,
    "mediaType": "publish",
    "mediaProvider": "Flash",
    "metrics": {
      "VIDEO_SYNC": 43688,
      "VIDEO_K_FRAMES": 22,
      "AUDIO_SYNC": 43712,
      "VIDEO_NACK": 0,
      "AUDIO_RATE": 129408,
      "AUDIO_LOST": 0,
      "VIDEO_LOST": 0,
      "VIDEO_CODEC": 119,
      "VIDEO_B_FRAMES": 0,
      "VIDEO_PLI": 0,
      "AUDIO_CODEC": 96,
      "VIDEO_RATE": 1187440,
      "VIDEO_WIDTH": 640,
      "VIDEO_GOP_SIZE": 48,
      "VIDEO_HEIGHT": 360,
      "VIDEO_FPS": 24,
      "VIDEO_P_FRAMES": 1027
    }
  }
]

Return codes¶

Code	Reason
200	OK
404	Not found
500	Internal server error

Parameters¶

Parameter	Description	Example
display	Addituional stream parameters to be in response	["metrics"]
mediaSessionId	Media session Id	6af0baf1-f014-48d6-b285-c975951a402f
name	Stream name	stream1
published	Published or playing	true
hasVideo	Is there video in the stream?	true
hasAudio	Is there video in the stream?	true
status	Stream status	PUBLISHING
sdp	Stream SDP
audioCodec	Audio codec	mpeg4-generic
videoCodec	Video codec	H264
record	Stream is recording	false
width	Stream width at publishing moment	640
height	Stream height at publishing moment	360
transport	WebRTC or MPEG-TS stream transport used	UDP
cvoExtension	WebRTC picture orientation extension is used	false
createDate	Stream creation date	1616730493789
mediaType	Media session type: publish or play	publish
mediaProvider	Publishing or plaing stream provider (Flash for RTMP)	Flash
minBitrate	Transcoder parameters created by REST API
maxBitrate
quality
gop
fps
audioBitrate
codecImpl

Audio codec details displaying¶

Since build 5.2.1619 audio track samplerate and channels count are displayed:

{
    ...,
    "name": "stream1",
    ...,
    "audioCodec": "mpeg4-generic/48000/2",
    "videoCodec": "H264",
    ...
}

If there is no audio track in the stream, audioCodec will not be displayed.

Audio redundancy statistics displaying¶

Since build 5.2.2066 audio redundency statistics may be displayed by request

POST /rest-api/stream/find HTTP/1.1
Host: localhost:8081
Content-Type: application/json

{
   "name":"stream1",
   "published":true,
   "display":["red"]
}

A published stream statistics example

{
    ...,
    "name": "stream1",
    ...,
    "red": {
        "output": {
            "totalRedundantBytes": 0,
            "totalRedundantPackets": 0
        },
        "input": {
            "totalRedundantBytes": 862151,
            "usedRedundantBytes": 24115,
            "totalRedundantPackets": 24633,
            "usedRedundantPackets": 689
        }
    }
}

Where:

totalRedundantBytes - total redundant bytes count
usedRedundantBytes - used redundant bytes count
totalRedundantPackets - total redundant packets count
usedRedundantPackets - used redundant packets count

The statistics shows non-null values when audio redundancy support (RED) is enabled

codecs=red,opus,...

Receiving stream metrics only¶