Sustainability of Digital Formats: Planning for Library of Congress Collections
Sustainability of Digital Formats: Planning for Library of Congress Collections |
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| Introduction | Sustainability Factors | Content Categories | Format Descriptions | Contact | |
| Full name | Direct Stream Digital Interchange File Format, DSDIFF, Version 1.5 |
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| 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 | The Library of Congress includes a small number of Direct Stream Digital files, especially in the Motion Picture, Broadcasting, and Recorded Sound Division. |
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| LC preference | The Library of Congress Recommended Formats Statement (RFS) includes DSD as a preferred format for audio on tangible media. The RFS does not specify a version of DSD. |
| Disclosure | Developed by Royal Philips Electronics of the Netherlands, now overseen by Sonic Studio LLC. |
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| 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. Accessibility Features There are no specific attributes to support accessibility but the Comments chunk could potentially store transcription or caption data, assigned along a timeline through timestamps, in the Reserved section. But this may not be practical in reality. Comments welcome. In common practice, typically sound content is supported by external caption and subtitle formats such as WebVTT. See W3C's Making Audio and Video Media Accessible for more general information about accessible sound and moving image media. |
| External dependencies | Not investigated. |
| Technical protection considerations | None indicated in specification. |
| Sound | |
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| 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 |
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| 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 | df0 df1 df2 df3 df4 df5 df6 df7 df8 df9 |
For a DSDIFF_1_5 Division File, not to exceed ten in number; see Recommended Usage, p. 16 |
| Internet Media Type | Not found. | Comments welcome. |
| Magic numbers | Hex: 46524D38{8}4453442046564552 ASCII: FRM8{8}DSD FVER |
See http://www.nationalarchives.gov.uk/PRONOM/fmt/1818. |
| Pronom PUID | fmt/1818 |
See http://www.nationalarchives.gov.uk/PRONOM/fmt/1818. |
| Wikidata Title ID | See note. | Wikidata has no corresponding entry as of April 2024. |
| General | |
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| History |
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