Alert

Overview

Alert is a module that can detect anomalies and patterns of interest in a stream or system and send notifications to users. Anomalies and patterns of interest can be set through predefined , and when detected, the module sends an HTTP(S) request to the user's notification server.

Configuration

Alert can be set up on <Server>, as shown below.

<Server version="8">
	<Alert>
		<Url>http://192.168.0.161:9595/alert/notification</Url>
		<SecretKey>1234</SecretKey>
		<Timeout>3000</Timeout>
		<Rules>
			<Ingress>
				<MinBitrate>2000000</MinBitrate>
				<MaxBitrate>4000000</MaxBitrate>
				<MinFramerate>15</MinFramerate>
				<MaxFramerate>60</MaxFramerate>
				<MinWidth>1280</MinWidth>
				<MinHeight>720</MinHeight>
				<MaxWidth>1920</MaxWidth>
				<MaxHeight>1080</MaxHeight>
				<MinSamplerate>16000</MinSamplerate>
				<MaxSamplerate>50400</MaxSamplerate>
				<LongKeyFrameInterval />
				<HasBFrames />
			</Ingress>
		</Rules>
	</Alert>
</Server>
Key
Description

Url

The HTTP Server to receive the notification. HTTP and HTTPS are available.

Secretkey

The secret key used when encrypting with HMAC-SHA1

Timeout

Time to wait for a response after request. (in milliseconds)

Rules

Anomalies and patterns of interest to be detected.

Rules

Key
Description

Ingress

MinBitrate

Detects when the input stream's bitrate is lower than the set value.

MaxBitrate

Detects when the input stream's bitrate is greater than the set value.

MinFramerate

Detects when the input stream's framerate is lower than the set value.

MaxFramerate

Detects when the input stream's framerate is greater than the set value.

MinWidth

Detects when the input stream's width is lower than the set value.

MaxWidth

Detects when the input stream's width is greater than the set value.

MinHeight

Detects when the input stream's height is lower than the set value.

MaxHeight

Detects when the input stream's height is greater than the set value.

MinSamplerate

Detects when the input stream's samplerate is lower than the set value.

MaxSamplerate

Detects when the input stream's samplerate is greater than the set value.

LongKeyFrameInterval

Detects when the input stream's keyframe interval is too long (exceeds 4 seconds).

HasBFrames

Detects when there are B-frames in the input stream.

Notification

Request

Format

POST /configured/target/url/ HTTP/1.1
Content-Length: 1037
Content-Type: application/json
Accept: application/json
X-OME-Signature: f871jd991jj1929jsjd91pqa0amm1
{
	"sourceUri":"#default#app/stream",
	"messages":[
		{
			"code":"INGRESS_HAS_BFRAME",
			"description":"There are B-Frames in the ingress stream."
		},
		{
			"code":"INGRESS_BITRATE_LOW",
			"description":"The ingress stream's current bitrate (316228 bps) is lower than the configured bitrate (2000000 bps)"
		}
	],
	"sourceInfo":{
		"createdTime":"2023-04-07T21:15:24.487+09:00",
		"sourceType":"Rtmp",
		"sourceUrl":"TCP://192.168.0.220:10639",
		"tracks":[
			{
				"id":0,
				"name":"Video",
				"type":"Video",
				"video":{
					"bitrate":"300000",
					"bypass":false,
					"codec":"H264",
					"framerate":30.0,
					"hasBframes":true,
					"height":1080,
					"keyFrameInterval":0,
					"width":1920
				}
			},
			{
				"audio":{
					"bitrate":"160000",
					"bypass":false,
					"channel":1,
					"codec":"AAC",
					"samplerate":48000
				},
				"id":1,
				"name":"Audio",
				"type":"Audio"
			},
			{
				"id":2,
				"name":"Data",
				"type":"Data"
			}
		]
	},
	"type":"INGRESS"
}

Here is a detailed explanation of each element of JSON payload:

Element
Description

sourceUri

URI information of the detected source.

It consists of #<vhost>#<application>/<stream>.

messages

List of messages detected by the Rules.

sourceInfo

Detailed information about the source at the time of detection. It is identical to the response of the REST API's source information query for the detected source.

type

It represents the format of the JSON payload. The information of the JSON elements can vary depending on the value of the type.

Currently, the value is fixed as INGRESS.

Messages

Code
Description

INGRESS_BITRATE_LOW

The ingress stream's current bitrate (%d bps) is lower than the configured bitrate (%d bps)

INGRESS_BITRATE_HIGH

The ingress stream's current bitrate (%d bps) is higher than the configured bitrate (%d bps)

INGRESS_FRAMERATE_LOW

The ingress stream's current framerate (%.2f fps) is lower than the configured framerate (%.2f fps)

INGRESS_FRAMERATE_HIGH

The ingress stream's current framerate (%f fps) is higher than the configured framerate (%f fps)

INGRESS_WIDTH_SMALL

The ingress stream's width (%d) is smaller than the configured width (%d)

INGRESS_WIDTH_LARGE

The ingress stream's width (%d) is larger than the configured width (%d)

INGRESS_HEIGHT_SMALL

The ingress stream's height (%d) is smaller than the configured height (%d)

INGRESS_HEIGHT_LARGE

The ingress stream's height (%d) is larger than the configured height (%d)

INGRESS_SAMPLERATE_LOW

The ingress stream's current samplerate (%d) is lower than the configured samplerate (%d)

INGRESS_SAMPLERATE_HIGH

The ingress stream's current samplerate (%d) is higher than the configured samplerate (%d)

INGRESS_LONG_KEY_FRAME_INTERVAL

The ingress stream's current keyframe interval (%.1f seconds) is too long. Please use a keyframe interval of 4 seconds or less

INGRESS_HAS_BFRAME

There are B-Frames in the ingress stream

Security

The control server may need to validate incoming http requests for security reasons. To do this, the AdmissionWebhooks module puts the X-OME-Signature value in the HTTP request header. X-OME-Signature is a base64 url safe encoded value obtained by encrypting the payload of an HTTP request with the HMAC-SHA1 algorithm using the secret key set in <Alert><SecretKey> of the configuration.

Response

The engine in the closing state does not need any parameter in response. To the query just answer with empty JSON object.

HTTP/1.1 200 OK
Content-Length: 5
Content-Type: application/json
Connection: Closed
{
}