Preservation

Motion Picture Film HD MP4 (Custom Bitrate) [MPD-D4]

Record Type: Digital Output from Motion Picture Film Source

Expected Use: Distribution Copy

Product Name: Motion Picture Film HD MP4 (Custom Bitrate) [MPD-D4]

Product Purpose: The purpose of this product is to respond to reference and reproduction requests for exhibits, Presidential Libraries, and special projects. It is not retained after delivery.

Nature of Source Material: This product is created from any 4K ProRes 4444 MOV (QuickTime File Format), HD (High Definition) AVI (Audio Video Interleaved), or MP4 reproduction master video file from film-based source material.

Possible File Derivatives: Derivatives are not made from this product category.

File Properties

Container Format

MP4 File Format (MPEG-4 Part 14)

File Specifications

Target Total Bitrate: Project dependent


Video Data

  • Video frame size: 1920x1080
  • Aspect Ratio: 16:9 (4:3 image with pillarboxes)
  • Video codec: Advanced Video Codec (avc1)
  • Video bitrate: Project dependent
  • Video mode: CBR
  • Video frame rate: 24 fps
  • High Profile @ Level 4.0 or 4.1
  • Color space: YUV
  • Chroma subsampling: 4:2:0
  • Bit depth: 8 bit
  • Progressive

 

Audio Data

  • Audio channels: 2 (stereo L R)
  • Audio bitrate: Project dependent
  • Audio codec: Advanced Audio Codec (AAC)
  • Audio mode: CBR
  • Audio sample rate: 48 kHz
  • Bit depth: 16 bit

 

Typical file size: Project dependent

Quality Control

Quality Assurance and Quality Control for Distribution Copy Video Files

The National Archives and Records Administration (NARA) uses a commercially available, automated batch processing software tool to evaluate specific quality metrics for files created directly from film captures (see MPD-R1 and MPD-R2). The MP4 derivative described here is sourced from a4K MOV, HD AVI, or MP4 reproduction master file following the NARA Film Reference standard operating procedure (SOP). We rely on visual quality control (QC) and spot checks to confirm completeness and accuracy of slates, as well as technical characteristics of the files. If an MP4 does not meet specified requirements, a new file is created from the source.

Metadata

The MP4 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. To distinguish this file from the 50Mbps HD MP4 distribution master, a suffix identifying the bit rate is appended to the filename (ex. 255-hq-199-r2_15Mbps.mp4).

Rationale

Sometimes internal customers require an HD MP4 product with a different bitrate from other described MP4 distribution copies. In such cases a derivative file with the needed bitrate may be created, though it is not retained after delivery.

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