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 For more information, see Security.
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
{
}