Video Born-Digital Original - SD & HD [VID-P4]
Record Type: Digital Moving Images from Video Source Material
Expected Use: Preservation Master
Product Name: Video Born-Digital Original - SD and HD [VID-P4]
Product Purpose: The purpose of this product is to mitigate risk for loss of information. This file is at an appropriate information capture level to substitute for the original record if the original record copy is no longer viable.
Nature of Source Material: All born-digital standard definition (SD) or high definition (HD) video with or without sound that can be extracted as data where there is a need to ensure that all significant visual and auditory information is carried forward. This includes digital videotapes with encodings that can be extracted as data and file based digital video. These formats are identified in section B2.4of International Association of Sound and Audiovisual Archives (IASA) TC-06 in Classes 3 and 4.
File Properties
| Data Format |
|---|
| Depends on source material |
| File Specifications |
|---|
|
Target Total Bitrate: To match original Timecode: To match original Video Data:
Audio Data:
Typical File Size: Dependent on source material |
Quality Control
Quality Assurance and Quality Control for Born Digital SD and HD AVI Video Products
The National Archives and Records Administration (NARA) uses a commercially available, automated batch processing software tool to evaluate specific quality metrics. Current processes are dependent on the born-digital original media.
Metadata
The filename contains metadata that associates the file with external sources of descriptive and technical metadata. Each filename is a unique identifier composed of the item’s record group, series, and item number.
Embedded metadata: NARA is working to develop embedded metadata guidelines for reformatted video. Additional information will be added to this site when available.
Technical metadata: NARA uses its reVTMD schema for video technical metadata.
Item Level Evaluation: Automated File Characteristics Analysis
Fixity: NARA creates a checksum on the local workstation where the file is created. This checksum is verified once the file reaches long-term tape storage to ensure that no changes have occurred during quality assurance (QA)/quality control (QC) procedures and file transfers on networked storage.
Item Level Evaluation: Automated Quality Analysis
Using automated batch processing software tools, test plans are developed for each format and/or each appropriate project. The test plan allows for some characteristics to be evaluated on an actionable basis (warning, fail, or pass depending on the defined parameters). Others are logged for internal use but are not actionable as a warning, pass or fail. Aim points for these benchmarks are evaluated against NARA's product specifications as well as NARA-defined aim points which may change depending on specific project goals.
Terms used in the QC protocols are defined in the Glossary of Terms.
Rationale
For products created from SD and HD born-digital video source material, the specifications are dictated to some extent by hardware and software capabilities.
Currently, the Audio-Video Preservation Lab creates uncompressed video streams in an AVI (Audio Video Interleaved) wrapper for the SD and HD preservation master product option. All video is ingested on equipment that is calibrated to allow for ITU-R Recommendation BT.601 and BT.709 compliance, but also to allow for safe capture of graphics and other computer-generated materials that may contain luminance values in the superwhite range. This method of calibration and capturing supports the most authentic replication of the original source material.
The choice of wrapper and codec was one that NARA staff looked at very critically. We continue to monitor developments in the area of wrapper, codec and toolset development. We see AVI, MOV, MXF, and MKV as the most viable options. Each has pros and cons. NARA has decided to use the AVI wrapper for a variety of reasons including:
Both the robotic capture system as well as the manual capture system can natively capture in AVI. (Only the robotic capture system has the option to capture in MOV; the manual capture system cannot natively capture in MOV.)
While the AVI wrapper has somewhat limited support for timecode, we are able to capture a start timecode from which the remainder of a timecode track could be generated if required.
AVI files are playable in a wide variety of open source tools including VLC.
The digital preservation master products produced by the Audio-Video Preservation Lab are in line with published guidelines and best practices including the IASA TC-06: Guidelines for the Preservation of Video Recordings.
NARA’s options for reproduction masters are in line with peer institutions.