Archival Formats & Conversion Workflows
Preserving digital records means preserving the information, not necessarily the original proprietary file wrapper.
Target Archival Standards
| Media Type | Avoid (Proprietary / Obsolescent) | Use for Preservation | Primary Tool |
|---|---|---|---|
| Video | RealMedia, WMV, ProRes, MPEG-2 | FFV1 in Matroska (.mkv) | ffmpeg |
| Audio | WMA, RealAudio, Lossy MP3 (for masters) | FLAC or Uncompressed WAV | ffmpeg / sox |
| Documents | DOCX, Pages, XLS | PDF/A-2b or PDF/A-3 | ghostscript / libreoffice |
| Images | Proprietary RAW (CR2/NEF), HEIC | Uncompressed TIFF or PNG | exiftool / imagemagick |
CLI Conversion Recipes
1. Convert Master Video Archives to FFV1 + FLAC
FFV1 is an open-source, mathematically lossless intra-frame video codec standardized by the IETF (RFC 9043) and recommended by the US Library of Congress.
# Transcode legacy or raw video into losslessly compressed FFV1 with FLAC audio
ffmpeg -i input_video.mov \
-c:v ffv1 -level 3 -coder 1 -context 1 -g 1 \
-c:a flac \
output_preservation.mkv
-level 3: Enables slice-level CRC checksum validation per frame.-g 1: Enforces intra-frame keyframing so each frame is self-contained.
2. Convert Documents to PDF/A-2b
PDF/A strips embedded links, dynamic scripts, and external font dependencies to guarantee static document rendering across decades:
# Convert standard PDF into archival PDF/A-2b format
ghostscript -dPDFA=2 -dBATCH -dNOPAUSE \
-sColorConversionStrategy=UseDeviceIndependentColor \
-sDEVICE=pdfwrite -dPDFACompatibilityPolicy=1 \
-sOutputFile=archival_doc.pdf input_doc.pdf
3. Preserve Metadata Sidecars
Extract embedded EXIF/IPTC metadata into a JSON sidecar before image processing: