1.4 Functional Architecture
Signal Hierarchy
MultiProbe organizes monitoring data in a three-level hierarchy:
Signal → Service → Component
In some cases a service level may be absent — for example, in RTMP streams where decoders are attached directly to the signal. A monitoring object can represent any level of this hierarchy: a signal, a service, or an individual component.
How MultiProbe Processes Signals
MultiProbe receives signals from monitoring objects via Ethernet or installed interface cards. The processing pipeline works as follows:
- Signal reception — data is received through Ethernet or a hardware interface card
- Decoding — signals are decoded using functional blocks called decoders
- Metric extraction — indicators (metrics) are extracted from the decoded signal
- Analysis — metrics are compared against user-defined alarm criteria using analyzers
- Alarm generation — if a criterion is met, an alarm event is created and the user is notified
Figure 5. Simplified functional diagram of MultiProbe
Decoders
Decoders are functional blocks responsible for extracting data from incoming signals. MultiProbe includes two decoder groups:
- Signal decoders — for uncompressed (studio) signals such as SDI
- MPEG decoders — for compressed signals and transport streams
To configure decoders, presets are used — reusable settings that define how a signal should be decoded and analyzed. A collection of presets effectively serves as a reference configuration against which real signals are compared. Presets are covered in detail in Section 5.
Available Decoders
| Decoder | Group | Purpose |
|---|---|---|
| Audio (Signal) | Signal | Extracts audio from studio signals |
| Video (Signal) | Signal | Extracts video from studio signals |
| VBI Teletext | Signal | Extracts VBI teletext from studio signals |
| VANC Teletext | Signal | Extracts VANC teletext from studio signals |
| SCTE-104 | Signal | Extracts SCTE-104 insertion markers (no configuration required) |
| Timecode | Signal | Extracts timecodes (no configuration required) |
| Audio (MPEG) | MPEG | Extracts audio from MPEG TS (one PID per decoder) |
| Video (MPEG) | MPEG | Extracts video from MPEG TS (one PID per decoder) |
| Stream | MPEG | Monitors selected PIDs without specifying stream contents |
| RT Audio | MPEG | Extracts audio from RTMP streams — added directly to the signal |
| RT Video | MPEG | Extracts video from RTMP streams — added directly to the signal |
| CEA Captions | MPEG | Extracts CEA-608/708 subtitles from MPEG streams |
| DVB Subtitles | MPEG | Extracts DVB subtitles (non-TTML) from MPEG streams |
| TTML | MPEG | Extracts DVB TTML subtitles from MPEG streams |
| SCTE-35 | MPEG | Extracts SCTE-35 insertion tags from MPEG TS streams |
| OTT SCTE-35 | MPEG | Extracts SCTE-35 insertion tags from OTT streams |
| ARIB Subtitles | MPEG | Extracts ARIB subtitles from MPEG streams |
Info
If a required decoder or analyzer is not available out of the box, it can be implemented using the MultiProbe scripting mechanism.
Signal and Service Relationships
The hierarchy of decoders, services, signals, and streams is illustrated below. Templates follow the same hierarchical structure.
Figure 6. Decoders, signals, services and streams
Warning
Each service template is compatible only with its corresponding decoder templates. Refer to the tables below for supported combinations.
Services and Their Compatible Decoders
| Service | Compatible Decoders | Purpose |
|---|---|---|
| SDI service | Audio (Signal), Video (Signal), VBI Teletext, VANC Teletext, SCTE-104, Timecode | Groups components in SDI, HDMI, 3G-SDI, UHD-SDI, ST 2110, ST 2022 signals |
| CVBS service | Audio (Signal), Video (Signal), VBI Teletext, VANC Teletext, SCTE-104, Timecode | Groups components in analogue signals (PAL, SECAM, NTSC) |
| MPEG-TS service | Audio (MPEG), Video (MPEG), CEA Captions, DVB Subtitles, DVB TTML, OTT SCTE-35, Stream, Teletext, ARIB Subtitles | Groups components in MPEG TS and OTT streams |
Signals and Their Compatible Services
| Signal | Services / Decoders | Purpose |
|---|---|---|
| RTMP | RT Video, RT Audio | Monitors RTMP streams. Decoders are added directly — no service level required |
| RTSP | RT Video, RT Audio | Monitors RTSP streams. Decoders are added directly — no service level required |
| T2-MI | Not required | Monitors T2-MI signals received from a tuner installed on the server |
| SDI | SDI service | Monitors SDI signals (SD, HD, UHD) |
| SDI over IP | SDI service | Monitors SMPTE ST 2022-6 and SMPTE ST 2110 streams |
| NDI | Not required | Monitors NDI streams |
| CVBS | CVBS service | Monitors analogue signals (PAL, SECAM, NTSC) |
Tip
For devices not natively supported by MultiProbe — but capable of exposing data via a web interface, REST API, or SNMP — custom monitoring can be implemented using the scripting mechanism. Scripts can be written in any interpreter-based language such as Python.