I recently attended the 2012 Association of Moving Image Archivists (AMIA) Annual Conference, and digital video was a common thread in most of the presentations.  The topics ranged from how to digitize film, to providing online access to digital files, and ways to preserve born-digital video files.  There was also a workshop on using FFmpeg, an open source command line program (like DOS for those who remember it) to convert audio and video files into a variety of different formats.  When digital video is created many different codecs are used to decode or translate the raw data into something you can view.  Additionally digital video is wrapped together with its audio in a container to form a package.  Usually, the codec and container for a given video file format is specific to the proprietary software that was used to create the file.  FFmpeg is a tool archivists can use to decode and convert a multitude of audio and video file formats with differing codecs and containers into a preservation standard.

Last summer, Killian Escobedo, intern for the Digital Services Division, wrote about some of the challenges of born digital video preservation, including the occasional inability to determine the codec and container format for a given video file.  The FFmpeg family contains a program called ffprobe, which uses libraries of various codecs and containers (specifically called: libavcodec and libavformat) to extract technical metadata to determine the codec and container of just about any digital video file.  Also, the libavcodec and libavformat libraries can be integrated with open source media players like VLC, which will allow the program to play back any file that has a codec and container listed in the libraries.  One important aspect of these libraries is that a once a codec or container is added, it will only be removed if it poses a security risk.  This is especially important since materials are usually accessioned several years after they were created and FFmpeg can be used by archivists to access information about file formats that may have become obsolete as both the codec and container information is needed in order to play back digital video.

While FFmpeg contains several tools for analyzing existing digital video, its main purpose is to convert digital video and audio files from one codec and container format to another using a command line interface.  The transcoding process starts by removing the container and codec to get to the raw data of the video, and then encoding that information into the codec and container specified at the beginning of the transformation.  The commands to simply transcode the video from one container and codec to another are fairly basic, but FFmpeg also allows you to make additional transformations during the transcode process, such as specifying a new aspect ratio or bit rate for the video.  These transformations are not ideal for the preservation of digital video because they can drastically change how the video looks.  Additionally, FFmpeg can be used to perform a MD5 checksum on a video after it has been converted from one format to another with greater accuracy than programs like JHOVE or DROID because it will look at the frame by frame raw data contained within a video, which should remain the same, even once the codec and container have been changed.

Thanks to the workshop, I now have a greater understanding of how to use FFmpeg to convert our born-digital video to a preservation format.  I am looking forward to running ffprobe on the files that Killian was unable to identify to see if it can determine the codec and container formats of some of the more complicated files.  Hopefully, this will help with the development of a long term preservation plan for the multitude of codecs and containers that are rapidly becoming obsolete.

Related Resources

• Digital Video Preservation: Further Challenges for Preserving Digital Video and Beyond, The Bigger Picture blog, Smithsonian Institution Archives
• Association of Moving Image Archivists

Marcel Chotkowski LaFollette's newly published book, "Science on American Television: A History," examines the popularization of science on television from the 1940s to the turn of the twenty-first century.

During the 1950s and 1960s (as I described in a previous post), places like the Smithsonian tended to keep television at arm's length. By 1976, however, television dominated the cultural scene. Even Smithsonian Secretary S. Dillon Ripley had to admit that "if the masses won't come to museums," then museums must use the medium to reach the masses. That goal turned out to be more easily proposed than accomplished. Scientific and cultural institutions were forced to choose between trying to achieve maximum audiences through commercial broadcast or settling for public television's smaller circle of friends.

The noted Hollywood producer David L. Wolper made three highly-rated network specials with the Smithsonian during the 1970s, but Wolper's melodramatic style left many curators dismayed and disappointed. Public television offered a more dignified venue and The Ascent of Man (first shown in the United States in 1974), NOVA (which premiered in 1974), and Carl Sagan's Cosmos (1980) had shown that millions of people would turn to PBS to watch well-produced programs about science. When Smithsonian World premiered on PBS in 1984, it followed a proven formula. Rather than focusing exclusively on science, the series intertwined segments on socially relevant research and environmental conservation with discussion of the arts and humanities.

The first host of the series was neither a scientist nor a museum curator. At the time, David McCullough was best known for his popular histories (e.g., The Path Between the Seas). A single clip from Smithsonian World, where McCullough encounters an importunate camel, illustrates well why he soon became a television star. The telegenic, honey-voiced McCullough was a television "natural," at ease in front of the camera, with an engaging public persona.

The first season's programs emphasized that the institution's work stretched far beyond the National Mall. In "Desk in the Jungle," McCullough and Ripley discuss the misperception that scientists were "deskbound scholars locked away in small offices." Smithsonian field researchers were, in fact, advancing human understanding in jungles and on mountaintops--documenting entomological diversity, identifying new astronomical bodies, studying the geology of volcanoes, uncovering the ruins of ancient civilizations, and recording folk music and culture. "The Last Flower" episode described Smithsonian research to preserve endangered species around the world, such as botanical specimens that might someday yield new life-saving drugs.

Smithsonian World also gave special attention to female scientists, something unusual during an era when every other television science series was still hosted or narrated by a male. Whether through Watch Mr. Wizard’s avuncular Don Herbert or NOVA’s choice of on-camera experts, 1980s television was still unconsciously reinforcing gender-based cultural assumptions about who could (and should) become a scientist. When McCullough interviewed physical anthropologist Katharine Milton, the young, self-confident researcher (who was studying howler monkeys at the Smithsonian Tropical Research Institute on Panama's Barro Colorado Island) provided a new role model to television viewers and the narration underlined the long strenuous days Milton spent in dense tropical forests. In another program, McCullough talked with biologist Devra Kleiman about the National Zoological Park's project to conserve golden lion tamarins. Kleiman's intensity and intelligence shone on the screen as she described their research to understand tamarin behavior and diet.

Over six seasons, with occasionally dazzling film of research around the world, Smithsonian World attracted a loyal group of public television viewers and praise from critics. The series' most important contributions, however, may have been to open windows on aspects of science otherwise hidden from view, such as the intellectual passion that fuels long hours in the laboratory or months spent in the field. And by turning its spotlight on women scientists, Smithsonian World also helped to reinforce a timely message about who can speak for science and thereby to encourage all its young viewers, female and male alike, to dream of perhaps someday becoming a scientist.

Related Collections

• Accession 03-022: Office of Telecommunications, Production Records, 1979-1991, Smithsonian Institution Archives
• Accession 08-081: Office of Telecommunications, Productions, 1984-1991, 1995-1998, 2003, Smtihsonian Institution Archives

Related Resources

• Television and the Smithsonian: The Allure of Objects, The Bigger Picture blog, Smithsonian Institution Archives
• Television and the Smithsonian: The Moon Party and ‘Instant History’, The Bigger Picture blog, Smithsonian Institution Archives
• The Archival Legacy of Devra Kleiman, The Bigger Picture Blog, Smithsonian Institution Archives