Motion Picture Film Reference Delivery MP3 [MPD-D6]
Record Type: Digital Output from Motion Picture Film Source
Expected Use: Distribution Copy
Product Name: Motion Picture Film Reference Delivery MP3 [MPD-D6]
Product Purpose: The purpose of this product is to respond to reference requests. The file is suitable for delivery in the research room and online National Archives Catalog access and is not retained by the Motion Picture Preservation Lab.
Nature of Source Material: Any preservation master or reproduction master WAV (Waveform Audio File Format) file for an item for which the sound does not sync to a picture element.
Possible File Derivatives: Derivatives are not made from this product category.
Other Information: This product is only created for items in reference and reproduction requests for which an audio element does not sync to a picture element. If audio is able to be synced without editing or timescale manipulation, a synced MP4 will be delivered in lieu of separate picture and audio files.
File Properties
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Typical file size for Mono: 128 Kbps: ~ .96 MB/minute or .057 GB/hour Typical file size for Stereo: 256 Kbps: ~ 1.9 MB/ minute or .113 GB/hour |
Quality Control
Quality Control for Distribution Copy Audio Files
The Motion Picture Lab relies on visual and auditory quality control (QC) and spot checks to confirm completeness and technical characteristics of the files.
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, item number, and reel number (ex. 255-hq-199-r2.mp3). The National Archives and Records Administration (NARA) does not embed metadata into MP3 files.
Rationale
These files are created at a low bitrate optimized to be easily streamed or downloaded from the National Archives Catalog via an internet connection.