Video Median Capture - SD [VID-R1]
|Record Type||Digital Moving Images from Video Source Material|
|Expected Use||Reproduction Master|
|Product Name||Video Median Capture - SD [VID-R1]|
The purpose of this product is to respond to reference and reproduction requests.
|Nature of Source Material||
All standard definition video with or without sound not at risk due to deterioration or obsolescence.
|File Properties||Data Format||
Target Total Bitrate: 50.8 Mbps
Timecode: Source LTC/VITC
Typical file size: ~ 360 MB/minute or 21.6 GB/hour
|Possible File Derivatives||
This master file can be used to create distribution files of equal or lesser capture quality.
This product could also be used as a broadcast or production quality deliverable.
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 MPEG-2 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 HD MPEG-2 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
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.