Capture Specifications
Included below are the digital file formats and ancillary specifications for the encoding (digitization or transcoding) of audio and moving image content we typically use at the MSU Libraries. First, here are our file format profiles:
A Preservation File is the highest quality digital file, meant to be maintained in perpetuity and for creating copies of the original (not for transcoding access files). Whether transferred from an analog or digital source, each preservation profile outlined below is intended to maintain the fidelity of the original while avoiding secondary digital obsolescence.
A Mezzanine File is a mid-level surrogate for the preservation file: robust yet computationally manageable (i.e., compressed). This file is accessed for transcoding, editing, or cases where close review is necessary. It is also referred to as a "production-quality" file.
Access Files are available to researchers on-site or for streaming/download via the local network. Levels of access depend on the rights and permissions MSU Libraries has to distribute the content.
Audio
| Specification | Preservation File, Analog Source | Preservation File, Digital Source | Mezzanine File | Access File |
|---|---|---|---|---|
| Format | Broadcast Wave Format (BWF; .wav) | Broadcast Wave Format (BWF; .wav) | Broadcast Wave Format (BWF; .wav) | MP3 (MPEG-2 Audio Layer III) |
| Encoding | Uncompressed Linear Pulse Code Modulated Audio (LPCM) | Uncompressed Linear Pulse Code Modulated Audio (LPCM) | Uncompressed Linear Pulse Code Modulated Audio (LPCM) | MP3enc, Lame |
| Sampling rate | 96 kHz or 44.1 kHz (if spoken word) | Native (e.g., 44.1 or 48 kHz) | 44.1 kHz | 44.1 kHz |
| Bit depth | 24-bit or 16-bit (if spoken word) | Native (e.g., 16-bit) | 16-bit | N/A, not LPCM. Bitrate = 160 Kbps (mono) or 320 Kbps (stereo) |
Audio Sources
- International Association of Sound and Audiovisual Archives Technical Committee. (2009). Guidelines on the Production and Preservation of Digital Audio Objects (IASA-TC04, 2nd ed.) . Retrieved May 19, 2015.
- Casey, M., & Gordon, B. (2007). Sound Directions: Best Practices for Audio Preservation . Trustees of Indiana University and President and Fellows of Harvard University. Retrieved February 13, 2025.
Video
| Specification | Preservation File, Analog Source (NTSC) | Preservation File, Digital Source | Mezzanine File | Access File |
|---|---|---|---|---|
| Container/Format | Matroska (.mkv) | Matroska (.mkv) | QuickTime (.mov) | QuickTime (.mov) or H.264/MPEG-4 AVC (.mp4) |
| Encoding | FFV1 | Native (e.g., DV; H.264; IMX) | DV50 | H.264 |
Video Sources
- Federal Agencies Digitization Guidelines Initiative Audio-Visual Working Group. (2014). Creating and Archiving Born Digital Video . Retrieved May 19, 2015.
- Federal Agencies Digitization Guidelines Initiative Audio-Visual Working Group. (2014). Digital File Formats for Videotape Reformatting . Retrieved May 19, 2015.