Sustainability of Digital Formats
Planning for Library of Congress Collections
Sustainability of Digital Formats
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| Introduction | Sustainability Factors | Content Categories | Format Descriptions | Contact | |
| Full name | AVI (Audio Video Interleaved), DivX Video Codec |
| Description | File format that wraps a DivX video bitstream with other data chunks, e.g., audio. |
| Production phase | Generally a middle-state format (often used as the video source when producing lower-resolution streaming versions). Note: DivX version 6 codecs were released beginning in late 2005; at this writing (2010), the compiler of this page has not yet investigated whether AVI may also wrap DivX 6.x. |
| Relationship to other formats | |
| Subtype of | AVI |
| May contain | DivX_4 video codec, not documented at this time. |
| May contain | DivX_5 video codec |
| May contain | WAVE audio (interleaved with video) |
| May contain | MP3_CBR (constant bit rate) audio (interleaved with video) |
| LC experience or existing holdings | |
| LC preference | See AVI |
| Disclosure | See AVI and DivX |
| Documentation | See AVI and DivX |
| Adoption | AVI is widely adopted for video production and filemaking; the Ligos Corporation FAQ for the competing Indeo codec includes this statement: "Many video files being distributed over the Internet use the DivX AVI format . . . ." In early 2006, Google began to offer downloadable videos, including gvi files in the AVI_DivX format (said to be DivX4 with MP3 audio). |
| Licensing and patent claims | See AVI and DivX |
| Transparency | See DivX |
| Self-documentation | See AVI |
| External dependencies | See AVI |
| Technical protection considerations | See AVI |
| Normal rendering | Good support. |
| Clarity (support for high image resolution) | Moderate to good, given that this is a format typically used for compression and does not support interlaced video. Outcome will depend on the type and extent of compression, and the encoder used. High resolution work is limited in the Windows environment due to file size limits (2 GB with FAT 16 technology; theoretical 8 GB with later technologies). |
| Fidelity (support for high audio resolution) | See AVI |
| Support for multiple sound channels | See AVI |
| Functionality beyond normal video rendering | See AVI |
| Tag type | Value | Note |
| Filename Extension | avi | |
| Filename Extension | gvi | Extension for files downloaded from Google Video. |
| Internet Media Type | See AVI | |
| Magic numbers | See AVI | |
| Microsoft FOURCC | DIVX, DIV3, DIV4, DX50 | Only the first of these FOURCC codes (DIVX) is listed at the Microsoft registry. The others are listed elsewhere, presumably the numbered FOURCCs identify DivX versions 3 [if it existed], 4, and 5. |
| Microsoft FOURCC | goog | According to the Wikipedia (viewed April 4, 2006), the Google .gvi files "are just standard RIFF AVI files, with an extra list with the FOURCC 'goog' immediately following the header." When consulted in May 2010, the Wikipedia entry provided a more complex description of "save as" outcomes for those downloading Google videos, although the description of gvi files as "modified AVI files" with the goog fourcc code remained. |
| General | |
| History |
URLs
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URLs
• John McGowan's AVI Overview (http://www.jmcgowan.com/avi.html)
• John McGowan's AVI Audio and Video Codecs (http://www.jmcgowan.com/avicodecs.html)
• Support page for DivX FAQs (http://support.divx.com/)
• DivX Version History (http://support.divx.com/faq/view/supportFAQen060/DivX-Codec-Version-History)
• Microsoft registry of FOURCC codes and WAVE format indicators (http://msdn2.microsoft.com/en-us/library/ms867195.aspx). The archived 2001 version of this registry is at http://www.microsoft.com/whdc/archive/fourcc.mspx.
• Gary Kessler's File Signatures Table (http://www.garykessler.net/library/file_sigs.html).
• Google Video Wikipedia article. (http://en.wikipedia.org/wiki/Google_video).
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