Motion Picture Film Reproduction Master - Soundtrack Audio Data WAV [MPD-R6]

Record Type: Digital Output from Motion Picture Film Source

Expected Use: Reproduction Master

Product Name: Motion Picture Film Reproduction Master - Soundtrack Audio Data WAV [MPD-R6] 

Product Purpose: The purpose of this product is to respond to reference and reproduction requests. The product is retained to act as a source for distribution files.

Nature of Source Material: All ONT (Original Negative Track), DNT (Duplicate Negative Track), MPT (Master Positive Track), and MAG (Magnetic Track) soundtrack elements

  • that do not sync to a picture element (wild sound, audio only, etc.) and
  • in stable condition as demonstrated by a determination of “Medium” or below on the At Risk Assessment Guide.

Possible File Derivatives: This product can be used to make MP3 distribution files or synced video files.

File Properties

Container Format
File Specifications
  • Encoded to Linear Pulse Code Modulation (LPCM)
  • Sampling frequency: 48 kHz
  • Bit depth: 24 bit
  • Sound field: dual mono/stereo


Typical file size: ~17.28 MB/minute or ~1GB/hour

Quality Control

Quality Control for Digital Audio Files

The National Archives and Records Administration (NARA) uses a commercially available, automated batch processing software tool to evaluate specific quality metrics. Below is a description of our current processes for WAV products.

Equipment/System Evaluation

NARA implements scheduled service and calibration protocols according to manufacturer recommendations as well as on an "as needed" basis.


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, with the source element type appended as a suffix for WAV files (ex. 255-hq-199-r2_p.wav).

Embedded metadata compliance: NARA follows the Federal Agencies Digital Guidelines Initiative (FADGI) Embedded Metadata in Broadcast WAVE File Guidelines

Technical metadata: NARA uses BWF MetaEdit to embed basic technical metadata, including Coding History.

Item Level Evaluation: Automated Quality Analysis

Test plans are developed on a format/workflow basis in our automated quality control (QC) tool. 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. The following represents the quality test plan technical characteristics for reproduction master WAV products from motion picture film.

Check (Warning/Pass/Fail)
  • Sampling Frequency (Hz)
  • Audio Channels (Number)
  • Bits per sample (Number)
Logged data
  • Duration
  • Average audio level
  • Peak levels


The NARA Motion Picture Preservation Lab uses checksum verification for file transfers and for files in long-term storage.


This product is only created and retained 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 HD (High Definition) AVI (Audio Video Interleaved) file will be retained in lieu of separate picture and audio files.