Overview - IEC 62071-3:2005 (Format D-7) data stream format
IEC 62071-3:2005 defines the data stream format for the helical‑scan compressed digital video cassette system (Format D-7) using 6.35 mm magnetic tape. The standard specifies how DV‑based audio, data and compressed video (data structure per SMPTE 314M) are synchronously transported over the Serial Data Transport Interface (SDTI) defined in SMPTE 305M. It covers both 25 Mb/s and 50 Mb/s DV‑based structures, including faster‑than‑real‑time transmission scenarios for 525/60 and 625/50 SDTI systems. A bilingual edition (2013‑07) corresponds to the original English 2005 publication.
Key topics and technical requirements
- Stream block format: Payload is composed of fixed‑size stream blocks (170 words each) that include a secondary header, two DIF block IDs, two DIF block data areas and a 4‑word ECC block.
- SDTI identification: SDTI header packet values for this data stream are specified - SDTI data type word = 221; block type = 173 (with ECC) or 233 (without ECC).
- Secondary header fields:
- Reserved data words (3 words; default value 200).
- Signal type (ST) words (2 words) containing STVF ID and flags such as FF (field/frame frequency), DIF structure, DVF (DIF valid flag), FSNF (frame sequence number flag) and TRF (transmission rate flag).
- Transmission type (TT) word to indicate transmission parameters and sequencing.
- DIF mapping and ECC: Rules for DIF block ID mapping, DIF block data word layout and error correction code (ECC) placement and mapping are defined to ensure reliable transport.
- Transmission order & mapping structure: Detailed transmission ordering for frames and channel‑unit mapping for both 25 Mb/s and 50 Mb/s structures across 525/60 and 625/50 systems.
Practical applications and who uses it
- Broadcast and professional video equipment manufacturers implementing D‑7 VTR hardware and firmware.
- Systems integrators and broadcast engineers designing SDTI/SDI transport chains for archival ingest, slow/fast playback and faster‑than‑real‑time transfers.
- Archive managers and post‑production facilities that interoperate with tape formats and require precise stream mapping for DV‑based compressed video.
- Firmware/codec developers and test labs validating SDTI payload conformance, ECC behavior and DIF mappings.
Related standards
- SMPTE 305M - Serial Data Transport Interface (SDTI)
- SMPTE 314M - Data structure for DV‑based audio, data and compressed video
- SMPTE 322M - Format for transmission of DV compressed video (not covered by IEC 62071‑3)
Keywords: IEC 62071-3:2005, D‑7, data stream format, SDTI, SMPTE 305M, SMPTE 314M, DV‑based compressed video, 25 Mb/s, 50 Mb/s, ECC, DIF, stream block.