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⏱ PAT Interval

The Program Association Table (PAT) identifies each program in an MPEG transport stream and points receivers to the Program Map Table PID for each program.
PAT packets must continue to recur often enough that downstream processing can keep resolving program signaling while the stream is ingested.

What This Test Does​

The PAT Interval test checks whether PAT packets continue to appear often enough for the selected MPEG-TS validation profile during ingest.

The current implementation applies these PAT recurrence limits:

  • ATSC: 100 ms
  • DVB: 100 ms
  • Generic: 500 ms

If the application never detects a PAT at all, the rule also fails.

✅ Pass Criteria​

The test passes when:

  • ingest detects PAT packets
  • no gap between consecutive observed PAT packets exceeds the selected profile limit

Application result message:

No PAT interval violations were detected.

❌ Fail Criteria​

The test fails when:

  • a gap between consecutive PAT packets is greater than the selected profile limit
  • no PAT packets are detected during ingest

Application result messages can include:

  • No PAT packets were detected during ingest.
  • <n> PAT interval errors were detected.

Example​

Here a chart that shows a PAT interval gap.

PAT interval chart

Test file​

  • mpegts-pat-blackout.ts