Sustainability of Digital Formats
Planning for Library of Congress Collections
Sustainability of Digital Formats
|
|
|
|
| Introduction | Sustainability Factors | Content Categories | Format Descriptions | Contact | |
| Full name | Direct Stream Digital Interchange File Format, DSDIFF, Version 1.5 |
|---|---|
| Description | Format for the storage or exchange of one-bit delta sigma modulated audio, often called Direct Stream Digital, or for the losslessly compressed version called Direct Stream Transfer (DST). As of 2006, delta sigma modulation is almost exclusively disseminated to endusers on the tangible media format called Super Audio CDs (SACDs), developed by SONY in association with Philips. The DSDIFF_1_5 file format is used by music producers to store DSD content or to deliver it "to the label" for reproduction on SACDs. |
| Relationship to other formats | |
| Subtype of | IFF, IFF (EA Interchange File Format 1985) |
| May contain | DSD, One-bit Delta Sigma Audio Encoding |
| May contain | DST, Direct Stream Transfer format for lossless encoded DSD audio, not documented at this Web site |
| May contain | Marker information, in what is called a Time File, used to support certain editorial or production workflows, not documented at this Web site |
| LC experience or existing holdings | None, although the collections of the Motion Picture, Broadcasting, and Recorded Sound Division include SACDs. |
|---|---|
| LC preference | None. For preservation reformatting, the Library prefers Broadcast WAVE (WAVE_BWF_1 and WAVE_BWF_2). |
| Disclosure | Developed by Royal Philips Electronics of the Netherlands, now overseen by Sonic Studio LLC. |
|---|---|
| Documentation | Direct Stream Digital Interchange File Format, DSDIFF, Version 1.5 (2004) and Recommended Usage of DSDIFF Version 1.5. |
| Adoption | Adoption of file version unknown. |
| Licensing and patents | Not investigated. |
| Transparency | Transparent wrapper. DSD bitstream is relatively transparent; DST is likely to be less so. |
| Self-documentation | See IFF. |
| External dependencies | Not investigated. |
| Technical protection considerations | None indicated in specification. |
| Sound | |
|---|---|
| Normal rendering | Details unknown; this is a very specialized format for professional producers. |
| Fidelity (high audio resolution) | See DSD |
| Multiple channels | DSDIFF_1_5 files can be structured for 2 channels or for "5- or 6-channels" (presumably for 5.1 mixes). SACDs may contain a 2-channel stereo mix, a surround mix (usually the 5.1 layout), other mixes, or even multiple mmix versions. |
| Support for user-defined sounds, samples, and patches | Not applicable |
| Functionality beyond normal rendering | Not fully investigated. DSDIFF_1_5 files can be divided into ten Division Files to overcome size limits imposed by some operating systems. |
| Tag | Value | Note |
|---|---|---|
| Filename extension | dff |
Indicated in Recommended Usage, p. 16 |
| Filename extension | dft |
For a DSDIFF_1_5 Time File; see Recommended Usage, p. 18 |
| Filename extension | dfn (n is an integer from 0 to 9) |
For a DSDIFF_1_5 Division Files, not to exceed ten in number; see Recommended Usage, p. 16 |
| Internet Media Type | None found |
Comments welcome |
| Magic numbers | None found |
Comments welcome |
| General | |
|---|---|
| History |
|
|