Video Maximum Manual Capture - SD [VID-P1]
|Record Type||Digital Moving Images from Video Source Material|
|Expected Use||Preservation Master|
|Product Name||Video Maximum Manual Capture - SD [VID-P1]|
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 standard definition analog video with or without sound where there is a need to ensure that all significant visual and auditory information is carried forward.
Current SAMMA Robotic system is restricted to ¾” U-matic tapes only. All other formats are processed on the Edius workstations.
|File Properties||Data Format||
Container: AVI (Audio Video Interleaved)
Target Total Bitrate: ~177 Mbps
Timecode: Source LTC/VITC
Typical file size: ~ 1200 MB/minute or 72 GB/hour
|Possible File Derivatives||
This product is used to make SD MPEG-2 50MB 4:2:2 reproduction masters and distribution files.
Due to its very large file size, this product is generally not accessed directly by researchers.
Audio and video levels may be adjusted as appropriate during the initial capture process but otherwise, the preservation files are unaltered. Reproduction and distribution files may have additional image improvements such as minimal color correction if necessary.
Quality Assurance and Quality Control for SD AVI Format Products
NARA uses a commercially available, automated batch processing software tool to evaluate specific quality metrics. Below is a outline of our current processes for SD AVI formatted products. The exact aim point values are still in the testing phase. Once these values are confirmed, they will be added to this site. We continue to adjust our benchmarks and workflows as needed.
Color Bar Alignment
NARA is developing an in house job tracking order system to better coordinate work at the Branch level.
Item Level Evaluation: Automated File Characteristics 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. The following represents the quality test plan technical characteristics for AVI products.
Terms used in the QC protocols are defined in the Glossary of Terms.
For digital products created from video source material, the specifications are dictated to some extent by hardware and software capabilities.
Currently, the Video Preservation Lab creates uncompressed video streams in an AVI (Audio Video Interleaved) wrapper for the SD preservation master product option. All video is ingested on equipment that is calibrated to allow for ITU-R Recommendation BT.601 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.
We will continue to monitor codec and wrapper use within the professional community as well as toolsets development and reevaluate our products as needed, especially when HD video reformatting comes to the fore.
NARA’s options for reproduction masters are in line with peer institutions.