Preparing Modern Movie Digital Audio Files for Archive - Recommended Practices

Executive Summary:

It is very important to treat movie digital audio files correctly all through the process of capture, editing, mixing, mastering and distribution. It is then critical that these be organized for archiving in a manner that will be straightforward and easily usable in the future. This document details how to organize movie audio files for archive. The details of the actual media archiving and recommended procedures are left to a second document

A comprehensive list of audio elements to archive is presented, from master elements to original source elements, as well as audio dubbed into local languages. This is hyperlinked to a section that gives detailed information on organizing and formatting each audio element in preparation for final data archiving. General notes on specifications and recommendations for the preparation of audio for archive are also presented, including a short summary of technical metadata to capture.

This recommended practice is intended to serve as an “uber guide” to movie audio archiving, based on what is created for today’s tentpole titles. Lower budget productions may not create all of these audio elements, but should still organize and archive what is created in a similar manner. The recommendations presented here should serve as a template that can be referenced by any movie studio or facility, ensuring that movie soundtracks are properly archived and available in the future.

Purpose:

Audio production and post-production are entirely digital in today’s world, from the on-camera sound recordings through to the final audio that comes off the mixing stage. The entire workflow is dependent on the interoperability of the audio files that are generated in every part of the process. As these files are often shared over networks and common storage, no physical media is generated anywhere during the process (as was the case with analog production). Digital files by nature are ephemeral and only exist as bits on a storage device or in RAM. They can easily be mishandled, lost or erased. Tracking, managing, formatting, organizing, and naming of the files is a full-time job during the creation process, necessitating systematic, delineated procedures. Once the mixing is done and the project is complete, the audio should be archived in an organized and robust way that allows for reliable retrieval and future use. This presents its own unique set of challenges.

This document provides a recommended practice for preparing digital audio for archiving. It describes the audio elements that should be archived, with guidance for formatting and organization to ensure a consistent final turnover to the archive team.

Comprehensive List of Audio Files to Archive:

Below is a list of audio elements that should be archived, in outline form. There is additional detail about each element, formatting and recommendations for preparation. These sections are hyperlinked for easy navigation.

  1.      Original Version (OV) Audio Deliverables
    1. Master OV Elements
      1. Printmasters
        1. Theatrical
          1. Immersive
            1. Session
            2. ADM
            3. IAB
          2. 7.1
          3. 5.1
        2. Nearfield
          1. Immersive
            1. Session
            2. ADM
            3. IAB
          2. 7.1
          3. 5.1
          4. TwoTrack
      2. Stems
        1. Stem Types
          1. Dialogue
          2. Group ADR a.k.a. Crowd, Walla
          3. ADR
          4. Music
            1. Source
            2. Score
            3. Vocals
          5. Background/Ambiances
          6. Foley
            1. Footsteps
            2. Props
            3. Cloth
          7. Effects
          8. Sound Design
        2. Theatrical
          1. Immersive
          2. 7.1
          3. 5.1
        3. Nearfield
          1. Immersive
          2. 7.1
          3. 5.1
        4. Composited Stems - Dialogue, Music and Effects only
          1. 7.1
          2. 5.1
          3. Two-Track
      3. Music and Effects (M&E)
        1. Main M&E
        2. Optionals
        3. Theatrical
          1. Immersive
            1. Session
            2. ADM
          2. 7.1
          3. 5.1
        4. Nearfield
          1. Immersive
            1. Session
            2. ADM
          2. 5.1
          3. Two-Track
      4. Predubs/Premixes
    2. Ancillary OV Elements
      1. M&E Stems
        1. Stem types similar to main stems with M&E fill and splits used to make the Main M&E
        2. Theatrical
          1. Immersive
          2. 7.1
          3. 5.1
        3. Nearfield
          1. Immersive
          2. 7.1
          3. 5.1
      2. M&E Sweetener Stems
      3. Fully Filled FX Stem
        1. Theatrical
          1. Immersive
          2. 7.1
          3. 5.1
        2. Nearfield
          1. Immersive
          2. 7.1
          3. 5.1
      4. Dialogue mix sessions (if mix is done "in-the-box") for Localization reference
      5. Mixer Notes for Localized Mix
    3. OV Final Source Materials
      1. Sound editorial
        1. Dialogue
        2. Effects
        3. BG
        4. Foley
        5. Sound Design
      2. Music editorial
        1. Music editorial sessions
        2. Music source stems
        3. Prerecords
        4. Source music
        5. Written score and parts, lead sheets
        6. Mixer cue sheets (if output)
      3. Mix Sessions
        1. For "in-the-box) projects or partially "in-the-box" projects
          1. Dialogue mix session
          2. Music mix session
          3. Background mix session
          4. Foley mix session
          5. Effects mix session
          6. M&E mix session
          7. I/O file (piio or similar) for each session
          8. Renderer setup file (if applicable). Note type and version
          9. Plug-in list with versions (plug-ins are not delivered
        2. If some or all of the mix is a long-form console project, add
          1. Board specifics: model, firmware/software version
          2. Board input/output routing setup. Photos files helpful.
          3. Board automation files, clearly labeled as to what mix pass they refer.
      4. Temp Dubs
        1. Printmasters
          1. Immersive (if created)
          2. 7.1 (if created)
          3. 5.1
          4. Two-Track
        2. Stems
          1. Immersive (if created)
          2. 7.1 (if created)
          3. 5.1
        3. Composited Stems-Dialogue, Music and Effects only
          1. 7.1 (if created)
          2. 5.1
          3. Two-Track
        4. Sound Editorial
        5. Mix Sessions
    4. Production Archive
      1. On-Set Recordings (a.k.a. "sound rolls"
      2. Production Logs and Reports
      3. ADR recordings and "Coverage ADR"
      4. ADR Logs and Reports
      5. Foley Recordings
      6. Foley logs and Reports
      7. Field Recordings
      8. Field Recordings Logs and Reports
      9. Signature title-specific sound effects
      10. Multitrack music score
      11. Music Score Logs and Reports
      12. Custom title-specific source music
      13. Music publishing cue sheets
      14. Lines Scripts
  2. Dubbed Audio Deliverables
    1. Master Dubbed Elements
      1. Printmasters (per language)
        1. Theatrical
          1. Immersive
            1. Session
            2. ADM
            3. IAB
          2. 7.1
          3. 5.1
        2. Nearfield
          1. Immersive
            1. Session
            2. ADM
            3. IAB
          2. 7.1
          3. 5.1
          4. Two-Track
      2. Dubbed Dialogue Stems (per language, matching printmaster audio configuration)
        1. Theatrical
          1. Immersive
          2. 7.1
          3. 5.1
        2. Nearfield
          1. Immersive
          2. 7.1
          3. 5.1
          4. Two-Track
    2. Translated script and associated paperwork/language

General Notes - Specifications and Recommendations

  • Reverbs should be recorded into the OV printmasters, stems and M&E, as well as dubbed printmasters and Dialogue stems.
  • Audio files must be Broadcast Wave (.wav).
  • Sample rates and frame rates should reflect those used to natively create the elements. No conversions should be done prior to archiving.
  • Sample rate should be 48.00 kHz or 96.00 kHz. No fractional sample rates should be used.
  • Frame rates are generally 24.00 for theatrical elements and 23.976 or 24.00 for nearfield elements. If the theatrical elements were mixed natively in 23.976, they should be archived as such.
  • All Master audio elements must be conformed to the final picture version.
  • Partitioning can be in reels or long form.
  • If the partitioning is in reels, it is recommended that all reels be in the same session. The file start for each reel should be at even timecode hours, hour = reel number. For example, reel 3’s files should start at 03:00:00:00.
  • Picture references at the frame rate of conform should be supplied. Both reels and long form picture should be supplied if audio is partitioned both ways.
  • Audio file start and picture file start should be the same with no offset required for them to run in sync.
  • Both head and tail sync pops should be on reference picture and all audio elements
  • For each Master audio element, there should be a DAW session in a project folder that contains the session file and all audio files that the session references and is thus self-contained. A checksum (e.g. MD5) and a READ ME should be included in the folder.
  • File naming is extremely important and should be done in a consistent manner, following an agreed file naming schema that is well-documented and available as a Rosetta Stone for future parsing of the archived files. One such schema is posted <put link here>.

Preparation for Archiving:

  • Data validation must be performed via checksum. Checksums must be created and supplied by the file creators to the archive team.
  • The checksum value should be put into the project folder of each audio element
  • Checksum example types:
    • MD5 (most commonly used as of this writing)
    • xxHash
    • SHA-1
    • SHA-256