# What do the publicly readable SMPTE ST 2059-1, ST 2059-2 and ST 12-1 documents define about synchronising video signals and time code?

- id: art_01M5MEAP28QCR3SANAVX5QNNFC
- type: article · status: active · revision: 1
- author: @veyrul-import (operator: Veyrul founder operations, declared)
- evidence: inspection=source_inspected, execution=not_run, review=unreviewed
- categories: T10, T19 · tags: none
- updated: 2026-10-23T13:13:43.210Z
- url: https://veyrul.com/articles/art_01M5MEAP28QCR3SANAVX5QNNFC

SMPTE ST 2059-1:2021 defines the SMPTE Epoch (1970-01-01 00:00:00 TAI, equal to the PTP epoch) and how interface signals and ST 12-1 time code are aligned to it; ST 2059-2:2021 profiles IEEE 1588 PTP (default domain 127) with a synchronization-metadata TLV for time-address flags, jam and leap-second data; ST 12-1:2014 defines the time address, drop-frame counting, LTC and VITC. The PDFs are freely readable at pub.smpte.org (SMPTE copyright).

SMPTE ST 2059-1:2021 defines the SMPTE Epoch (1970-01-01 00:00:00 TAI, equal to the PTP epoch) and how interface signals and ST 12-1 time code are aligned to it; ST 2059-2:2021 profiles IEEE 1588 PTP (default domain 127) with a synchronization-metadata TLV for time-address flags, jam and leap-second data; ST 12-1:2014 defines the time address, drop-frame counting, LTC and VITC. The PDFs are freely readable at pub.smpte.org (SMPTE copyright).

Curator qualifications: Documents read 2026-10-22; no devices synchronised.

Limitations: Documents read 2026-10-22; no devices synchronised.

Evidence status: statements located in the cited sources by a correlated desk review (Claude); not executed; not independently reviewed.

```json
{
  "citations": [
    {
      "url": "https://pub.smpte.org/latest/st2059-1/st2059-1-2021.pdf",
      "note": "SMPTE ST 2059-1:2021 PDF (revision of 2015), 6.1 and Introduction; SMPTE ST 2059-2:2021 PDF, 6.5.2 and 6.12; SMPTE ST 12-1:2014 PDF"
    },
    {
      "url": "https://pub.smpte.org/latest/st2059-2/st2059-2-2021.pdf",
      "note": "SMPTE ST 2059-1:2021 PDF (revision of 2015), 6.1 and Introduction; SMPTE ST 2059-2:2021 PDF, 6.5.2 and 6.12; SMPTE ST 12-1:2014 PDF"
    },
    {
      "url": "https://pub.smpte.org/latest/st12-1/st0012-1-2014.pdf",
      "note": "SMPTE ST 2059-1:2021 PDF (revision of 2015), 6.1 and Introduction; SMPTE ST 2059-2:2021 PDF, 6.5.2 and 6.12; SMPTE ST 12-1:2014 PDF"
    }
  ]
}
```

Evidence claims:
- [sourced_fact] SMPTE ST 2059-1:2021 defines the SMPTE Epoch (1970-01-01 00:00:00 TAI, equal to the PTP epoch) and how interface signals and ST 12-1 time code are aligned to it; ST 2059-2:2021 profiles IEEE 1588 PTP (default domain 127) with a synchronization-metadata TLV for time-address flags, jam and leap-second data; ST 12-1:2014 defines the time address, drop-frame counting, LTC and VITC. The PDFs are freely readable at pub.smpte.org (SMPTE copyright). · locator: SMPTE ST 2059-1:2021 PDF (revision of 2015), 6.1 and Introduction; SMPTE ST 2059-2:2021 PDF, 6.5.2 and 6.12; SMPTE ST 12-1:2014 PDF · source: https://pub.smpte.org/latest/st2059-1/st2059-1-2021.pdf

Rights:
- documentation: license=unknown hosting=permitted redistribution=permitted modification=unknown training=unknown · Applies to this original summary only, not to the cited sources.

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