Video formats
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Mini DV cameras capture video footage in a digital format on cassettes. The footage can be imported from the cassettes to computers, but Windows PCs typically lack ports for direct connection. Importing raw footage from a Mini DV cassette to an Apple computer results in large file sizes around 15GB per hour of footage. Compressing the footage using lossy codecs reduces the file size but results in some loss of quality or artifacts. NARA recommends lossless or named lossy codecs and open formats like MOV, AVI or MXF for long-term preservation of archival video.
Video formats
- 1. Archival Video Formats for mini DV Cameras Eric M. Stauffer, M.Ed. Instructional Technologist - ASCIT@UVA
- 2. Mini DV - Canon ZR 960 Cameras like the Canon ZR 960 use mini DV cassettes to capture digital video and audio. The video can be retrieved from the cassettes through the camera with an optional firewire cable. (Note: Mini DV cameras typically do not come with a firewire cable. Even if they did, most Windows based desktops and laptops do not have a mini DV as a standard port.) Apple computers after 2003 come with at least one firewire port standard. ( Note: Be advised that if you are purchasing a firewire cable for your Apple computer that they come in 4, 6 or 9 pin plug configurations. Check your destination machine’s port configuration prior to purchasing.) You may wish to import the raw *.dv footage on an Apple and then transfer to an external hard-drive for later editing and or storage on both Apple and Windows based computers.
- 3. Lossy Codec : A lossy codec is one that discards certain portions of the signal in order to achieve a smaller file size; for example, mp3 codecs attempt to identify and remove portions of the signal that would not result in a perceived loss of quality of the sound to make the file smaller. These losses are sometimes noticeable and sometimes not. The more aggressive the compression setting chosen, the more data is removed. This can result in digital artifacts, which are audible errors created by the compression. Lossless Codec : A lossless codec is one that achieves smaller file sizes through means other than removing data. This can include using a variable bit rate which would use fewer bits to encode silences as compared to an active section of music. There are two main types of codecs (formats)
- 4. When selecting a format consider the following aspects: http://www.archives.gov/records-mgmt/initiatives/dav-faq.html The format should be publicly and openly documented. The format is non-proprietary. The format is in widespread use. The format is self-documenting. The format can be opened, read, and accessed using readily-available tools.
- 5. What digital video formats does NARA recommend for federal records? Based on the suitability characteristics identified on the previous slide, the following formats are acceptable for digital video files: Audio-Video Interleave format (AVI) Material Exchange Format (MXF) Quicktime format (MOV) http://www.archives.gov/records-mgmt/initiatives/dav-faq.html
- 6. What are the preferred codecs for digital video formats? MPEG2 MPEG4 DV MJPEG2000 http://www.archives.gov/records-mgmt/initiatives/dav-faq.html NARA recommends lossless open codecs such as Motion JPEG 2000 or HuffyUV. However, when lossless codecs are not practical (e.g., business requirements for smaller file sizes), NARA suggests the following lossy codecs:
- 7. One tape is about 1 hour @ 13.56 GB or around 15 GB 1000 GB = 1 TB 100 hours X 15 GB = 1500 GB or about 1.5 TB Would require a 2 TB external hard-drive for your entire catalog. Local retail cost is between $100 and $125. It takes about 1 hour to import the raw data which results in a .dv file. The Math - Raw Archival
- 8. One tape is about 1 hour = 1.84 GB or about 2GB in MPEG-4 format at 960x540 native resolution. 1000 GB = 1 TB 100 hours X 2 GB = 200 GB or about .20 TB A 500 GB drive retails for about $60 - $80 locally. The result is a .m4v file playable on most Apples and PCs. The Math - Usable Lossy Format
- 9. One tape is about 1 hour = 8.65 GB or about 9GB in MPEG-4 format at 1920x1080 native resolution. 1000 GB = 1 TB 100 hours X 9 GB = 900 GB or roughly 1 TB A 500 GB drive retails for about $80 - $100 locally. Takes about 1 hour to import and 8 hours to encode. The result is a Quicktime .mov format. The Math - Usable Lossy Format
- 10. On the Other Hand If you are not editing or have a finished edited project and are looking for a way to share your footage there are many solutions to choose from. The most common way to share this footage would be to burn to DVD and mail a copy. DVD footage is in mpeg-2 and is good quality for most televisions and computer monitors. Once finalized, DVD data requires “ripping” to retrieve data from the disc to edit and can cause loss of both audio and video data in the process. A single DVD holds about 4.7 GB of data or about 2 hours of footage. 50 DVDs would hold 100 hours of .dv footage.