This document discusses file formats for audiovisual archiving, including considerations around chroma subsampling, uncompressed versus lossless and lossy compression, and born-compressed formats. It notes advantages and disadvantages of formats like TIFF, DPX, JPEG 2000, FFV1, and CineForm RAW. The document proposes encoding audiovisual content into Matroska containers using the FFV1 video codec and FLAC audio codec to preserve metadata and enable bit-by-bit decoding while providing compatibility with media players.

1. Reto Kromer • AV Preservation by reto.ch
Champions of Value and Trust:
AV Archives in the all-media world
FIAT/IFTA, Dubrovnik, Croatia
22–25 October 2019
The missing piece of software

2. Reading
Reto Kromer: Matroska and FFV1: One File
Format for Film and Video Archiving?,
in «Journal of Film Preservation», n. 96 (April
2017), FIAF, Brussels, Belgium, p. 41–45
➔ https://retokromer.ch/publications/
JFP_96.html

3. Compression
• chroma subsampling
• uncompressed
• lossless compression
• lossy compression
• compressed-born

4. Chroma Subsampling
• 4:4:4
• 4:2:2
• 4:2:0 / 4:1:1

5. Uncompressed
+ data simpler to process
+ software runs faster
– bigger files
– slower writing, transmission and reading
Examples: TIFF, DPX, OpenEXR

6. Lossless Compression
+ smaller files
+ faster writing, transmission and reading
– data processing complexer
– software runs slower
Examples: JPEG 2000, FFV1

7. Lossy Compression
• optimised for postproduction
Examples: ProRes 422, DNxHD, ProRes 4444,
DNxHR
• optimised for access
Examples: H.264 (AVC), H.265 (HEVC),
AV1

8. Born-Compressed
• optimised for both image acquisition and
postproduction
Examples: CineForm RAW, ProRes RAW

9. Bayer

10. container:
• folder
• TAR
• ZIP
• MXF
• Matroska
codec:
• TIFF
• DPX
• JPEG 2000
• FFV1
• OpenEXR
• CineForm RAW
• ProRes RAW

11. avantages disavantages
TIFF
DPX
OpenEXR
data easier
to process bigger files
JPEG 2000
FFV1
smaller files data complexer
to process

12. RAWcooked
• encoding into Matroska (.mkv) using FFV1
video codec and FLAC audio codec
• all metadata preserved
• decoding with bit-by-bit reversibility
• possibility to embed sidecar files (e.g.
MD5, LUT, XML)
• compatibility with media players

13. AV Preservation by reto.ch
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