Sustainability of Digital Formats
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DV-DIF (Digital Video Digital Interface Format)

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Format Description Properties Explanation of format description terms

Identification and description Explanation of format description terms

Full name DV-DIF (Digital Video Digital Interface Format)
Description

Interface format for DV, the Digital Video family of related video encodings (DV, DVCAM, and DVCPRO). A frame of data in the DV format stream is divided into several DIF sequences, each of which is composed of an integral number of 80-byte DIF blocks. DIF blocks are the basic units of DV streams, and each block contains a 3-byte ID header that specifies the block type and its position in the DIF sequence. There are five types of DIF blocks: DIF sequence header, Subcode, Video Auxiliary information (VAUX), Audio, and Video. DV-DIF blocks can be stored as files in raw form (.dv or .dif extension) or wrapped in such file formats as AVI, QuickTime, and MXF.

DV encoding is described in DV. More information on DV-DIF is provided in Notes below. Comments on this format description are welcome.

Production phase Generally a initial-state or middle-state format.
Relationship to other formats
    Used by DV, Digital Video Encoding (DV, DVCAM, DVCPRO)
    Used by AVI_DV, AVI, DV Digital Video
    Used by QTV_DV, QuickTime Video, DV Digital Video
    Used by MXF_GC_DV-DIF, MXF Generic Container Mapped to DV-DIF Data
    Used by Other file wrappers, not documented here

Local use Explanation of format description terms

LC experience or existing holdings See DV
LC preference See DV

Sustainability factors Explanation of format description terms

Disclosure See DV
    Documentation See DV
Adoption See DV
    Licensing and patents See DV
Transparency See DV
Self-documentation Pertains to the file format; see the subtypes listed above or the wrappers AVI, QuickTime, and MXF.
External dependencies None for files; see DV for information about videocassette applications.
Technical protection considerations Pertains to the file format; see the subtypes listed above or the wrappers AVI, QuickTime, and MXF.

Quality and functionality factors Explanation of format description terms

Moving Image
Normal rendering See DV
Clarity (high image resolution) See DV
Functionality beyond normal rendering See DV
Sound
Normal rendering See DV
Fidelity (high audio resolution) See DV
Functionality beyond normal rendering See DV

File type signifiers Explanation of format description terms

Tag Value Note
Filename extension dv
dif
For unwrapped "raw" files. For wrapped files, see AVI_DV, QTV_DV, and MXF_GC_DV-DIF.
Internet Media Type video/x-dv
For unwrapped "raw" files, from The File Extension Source. For wrapped files, see AVI_DV, QTV_DV, and MXF_GC_DV-DIF.
Magic numbers Not found.  Comments welcome. 

None discovered for raw files


Notes Explanation of format description terms

General

SMPTE 383M (MXF Mapping of DV-DIF to Generic Container) reports that single-frame distributions of DV-DIF data are defined in SMPTE 314M, SMPTE 370M, IEC 61834-2 (for a complete list of specification documents, see DV format specifications). SMPTE 383M (page 2) also reports:

  • For 60-cycle systems, there are ten identical DIF sequences in each DIF channel.
  • For 50-cycle systems, twelve. Each DIF sequence is assigned to a DIF channel.
  • For 25 MB/s IEC DV and DV-based compression: one DIF channel.
  • For 50 MB/s DV-based compression: two channels.
  • For 100 MB/s DV-based compression: four channels.
History  

Format specifications Explanation of format description terms


Useful references

URLs


Last Updated: 11/04/2013