Video

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Preservation Format

MPEG-2

Access Format

OGG

Normalization tool

FFmpeg

Comments

• Video stream will be converted to MPEG-2 with Intra-coded (I) frames; audio stream will be converted to LPCM with a bit depth of 16 bits and a sampling frequency of 48000 HZ; wrapper format is MXF (Material Exchange Format).
• According to Library of Congress, "For file-based compressed video, conform to or approximate MPEG-2_422 (4:2:2 Profile) at Main Level (aka MPEG-2 422@ML) or MPEG-2_MP (Main Profile) at Main Level (aka MPEG-2 MP@ML). Uncompressed or losslessly compressed copies are preferred to compressed (for future development)." Library of Congress Sustainability of Digital Formats: MPEG-2 Video Encoding (H.262)
• Video stream preservation issues:
  • From Lossless Video Compression for Archives: Motion JPEG2k and Other Options, Ian Gilmour, National Film and Sound Archive, Australia, R. Justin Dávila, System Architect and Technology Consultant, Media Matters LLC, date unknown: "Archivists have a short list from which to select a digital archival file format for a modern, 21st Century migration project. Such an archival file should have the requirement of being both lossless to preserve content and also compressed to conserve storage capacity. The leading candidate for such a file format is Motion JPEG 2000. Two complementary image compression schemes are in widespread use: JPEG and MPEG, along with some other, less standardized options. The original JPEG has been used for many years in compressing full color images. JPEG-2000 uses wavelet compression as adopted for the Digital Cinema Initiative (DCI), and enables true lossless compression. MPEG-4 is being adopted rapidly for transmission of audio, video and other data at lower bit-rates for similar quality compared to previous MPEG standards. MPEG-4 part 10 Advanced Video Coding, also known as ITU H.264 typically achieves file sizes and data rates half the rates used in MPEG-2. For MPEG-4, in two very specific instances, known as PCM-I, and Transform bypass, the MPEG-4 toolset allows for lossless encoding of finite picture regions or macroblocks. However, when taken as a whole, the MPEG-4 tool set is not designed to support lossless encoding of entire picture sequences, with any significant degree of data reduction. JPEG-2000 is a technically better solution for this requirement." (p.1)
  • Digital Video Preservation Reformatting Project,Prepared by Media Matters, LLC for the Dance Heritage Coalition, Presented to The Andrew W. Mellon Foundation, June 2004 recommends JPEG 2000 encoding in an MXF container for long-term preservation of video files. (p.99)
• Audio stream preservation issues:
  • For preservation of audio streams, WAV PCM or WAV BWF are preferred formats and AIFF is acceptable. See Guidelines for the Creation of Digital Collections: Digitization Best Practices for Audio, Consortium of Academic and Research Libraries in Illinois, 2009, p. 2.