File Formats

extensionmediatypedefinition
files.xmlallthe manifest that records all of the files available for this book; also gives 2 checksums and a format definition for each file; provides the only mechanism for validating that the component data has been downloaded successfully
.sfvallSimple file verification (SFV) is a file format for storing CRC32 checksums of files to verify the integrity of files. SFV is used to verify that a file has not been corrupted, but it does not otherwise verify the file’s authenticity. https://en.wikipedia.org/wiki/Simple_file_verification
meta.xmlallInternet Archive’s internal “management” metadata; a proprietary XML format, this file includes information about the scan event (date, # of pages, operator, station, etc.), the contributor, basic bib data (title, author, subject, language), and a set of identifiers
.wmaaudioWindows Media Audio (WMA) is a series of audio codecs and their corresponding audio coding formats developed by Microsoft. https://en.wikipedia.org/wiki/Windows_Media_Audio
.wavaudioWaveform Audio File Format (WAV) is an audio file format standard for storing an audio bitstream. https://en.wikipedia.org/wiki/WAV
.oggaudioVorbis is a free and open-source software project. The project produces an audio coding format and software reference encoder/decoder (codec) for lossy audio compression. Vorbis is most commonly used in conjunction with the Ogg container format and it is therefore often referred to as Ogg Vorbis. https://en.wikipedia.org/wiki/Vorbis
.mp3audioVBR (Variable Bitrate) MP3 is a coding format for digital audio https://en.wikipedia.org/wiki/MP3
.m3uaudioVBR (Variable Bitrate) M3U is a computer file format for a multimedia playlist. One common use of the M3U file format is creating a single-entry playlist file pointing to a stream on the Internet. The created file provides easy access to that stream and is often used in downloads from a website, for emailing, and for listening to Internet radio. https://en.wikipedia.org/wiki/M3U
.shnaudioShorten (SHN) is a file format used for compressing audio data. It is a form of data compression of files and is used to losslessly compress CD-quality audio files. https://en.wikipedia.org/wiki/Shorten_(codec)
.mp3audioMP3 is a coding format for digital audio https://en.wikipedia.org/wiki/MP3
.m3uaudioM3U is a computer file format for a multimedia playlist. One common use of the M3U file format is creating a single-entry playlist file pointing to a stream on the Internet. The created file provides easy access to that stream and is often used in downloads from a website, for emailing, and for listening to Internet radio. https://en.wikipedia.org/wiki/M3U
sample.mp3audioLimited length MP3 audio file derived from source audio file. Typically 30 seconds in length.
.flacaudioFLAC is an audio coding format for lossless compression of digital audio, developed by the Xiph.Org Foundation, and is also the name of the free software project producing the FLAC tools, the reference software package that includes a codec implementation. https://en.wikipedia.org/wiki/FLAC
.aiffaudioAudio Interchange File Format (AIFF) is an audio file format standard used for storing sound data for personal computers and other electronic audio devices. https://en.wikipedia.org/wiki/Audio_Interchange_File_Format
.m4aaudioAdvanced Audio Coding (AAC) is an audio coding standard for lossy digital audio compression. Designed to be the successor of the MP3 format, AAC generally achieves higher sound quality than MP3 encoders at the same bit rate. https://en.wikipedia.org/wiki/Advanced_Audio_Coding
spectrogram.pngaudioA visual representation of the spectrum of frequencies of a signal as it varies with time.
.afpkaudio“audio fingerprinting” to enable comparing audio tracks together for “the same” tracks or portions of them
ffp.txtaudio“audio fingerprinting” to enable comparing audio tracks together for “the same” tracks or portions of them
esshigh.json.gzaudiohistorical audio format that tried to do analysis like beats-per-minute, deductions of “genre” of music, etc.
esslow.json.gzaudiohistorical audio format that tried to do analysis like beats-per-minute, deductions of “genre” of music, etc.
.ffpaudioa community-specific checksum for flac files, important to etree community
.zipdataZIP is an archive file format that supports lossless data compression. A ZIP file may contain one or more files or directories that may have been compressed. https://en.wikipedia.org/wiki/ZIP_(file_format)
.rtfdataThe Rich Text Format (often abbreviated RTF) is a proprietary document file format. Most word processors are able to read and write some versions of RTF. https://en.wikipedia.org/wiki/Rich_Text_Format
.odtdataThe Open Document Format for Office Applications (ODF), also known as OpenDocument, is an open standard file format for spreadsheets, charts, presentations and word processing documents using ZIP-compressed XML files https://en.wikipedia.org/wiki/OpenDocument
.htmldataThe HyperText Markup Language or HTML is the standard markup language for documents designed to be displayed in a web browser. It can be assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaScript. https://en.wikipedia.org/wiki/HTML
.swfdataSWF is an Adobe Flash file format used for multimedia, vector graphics. SWF files can contain animations or applets of varying degrees of interactivity and function. They may also occur in programs, commonly browser games, using ActionScript. https://en.wikipedia.org/wiki/SWF
.rardataRAR is a proprietary archive file format that supports data compression, error recovery and file spanning. https://en.wikipedia.org/wiki/RAR_(file_format)
.otfdataOpenType is a format for scalable computer fonts.. https://en.wikipedia.org/wiki/OpenType
.middataMIDI is a technical standard that describes a communications protocol, digital interface, and electrical connectors that connect a wide variety of electronic musical instruments, computers, and related audio devices for playing, editing, and recording music. https://en.wikipedia.org/wiki/MIDI
.docdataMicrosoft Word is a word processing software developed by Microsoft. https://en.wikipedia.org/wiki/Microsoft_Word
.pptdataMicrosoft PowerPoint is a presentation program. PowerPoint was originally designed to provide visuals for group presentations within business organizations, but has come to be very widely used in many other communication situations, both in business and beyond. https://en.wikipedia.org/wiki/Microsoft_PowerPoint
.xlsdataMicrosoft Excel is a spreadsheet developed by Microsoft. https://en.wikipedia.org/wiki/Microsoft_Excel
.jsondataJSON is an open standard file format and data interchange format that uses human-readable text to store and transmit data objects consisting of attribute–value pairs and arrays (or other serializable values). https://en.wikipedia.org/wiki/JSON
.tardataIn computing, tar is a computer software utility for collecting many files into one archive file, often referred to as a tarball, for distribution or backup purposes. https://en.wikipedia.org/wiki/Tar_(computing)
.txtdataIn computing, plain text is a loose term for data (e.g. file contents) that represent only characters of readable material but not its graphical representation nor other objects (floating-point numbers, images, etc.). https://en.wikipedia.org/wiki/Plain_text
.gzdatagzip is a file format and a software application used for file compression and decompression. https://en.wikipedia.org/wiki/Gzip
.flvdataFlash Video is a container file format used to deliver digital video content (e.g., TV shows, movies, etc.) over the Internet using Adobe Flash Player version 6 and newer. https://en.wikipedia.org/wiki/Flash_Video
.cssdataCascading Style Sheets (CSS) is a style sheet language used for describing the presentation of a document written in a markup language such as HTML. https://en.wikipedia.org/wiki/CSS
.isodataAn optical disc image (or ISO image, from the ISO 9660 file system used with CD-ROM media) is a disk image that contains everything that would be written to an optical disc, disk sector by disc sector, including the optical disc file system. https://en.wikipedia.org/wiki/Optical_disc_image
.aidataAdobe Illustrator Artwork (AI) is a proprietary file format developed by Adobe Systems for representing single-page vector-based drawings in either the EPS or PDF formats. The .ai filename extension is used by Adobe Illustrator. https://en.wikipedia.org/wiki/Adobe_Illustrator_Artwork
.tsvdataA tab-separated values (TSV) file is a simple text format for storing data in a tabular structure, e.g., a database table or spreadsheet data, and a way of exchanging information between databases. https://en.wikipedia.org/wiki/Tab-separated_values
.7zdata7z is a compressed archive file format that supports several different data compression, encryption and pre-processing algorithms. https://en.wikipedia.org/wiki/7z
.exedata.exe is a common filename extension denoting an executable file (the main execution point of a computer program) for Microsoft Windows. https://en.wikipedia.org/wiki/.exe
.gifimageThe Graphics Interchange Format is a bitmap image format that was developed by a team at the online services provider CompuServe. https://en.wikipedia.org/wiki/GIF
.tiffimageTag Image File Format, abbreviated TIFF or TIF, is an image file format for storing raster graphics images, popular among graphic artists, the publishing industry, and photographers. https://en.wikipedia.org/wiki/TIFF
.pngimagePortable Network Graphics is a raster-graphics file format that supports lossless data compression. https://en.wikipedia.org/wiki/Portable_Network_Graphics
.jpgimageJPEG is a commonly used method of lossy compression for digital images, particularly for those images produced by digital photography. https://en.wikipedia.org/wiki/JPEG
.jp2imageJPEG 2000 (JP2) is an image compression standard and coding system. https://en.wikipedia.org/wiki/JPEG_2000
.vttmoviesWebVTT (Web Video Text Tracks) is a (W3C standard for displaying timed text in connection with the HTML5 <track> element. https://en.wikipedia.org/wiki/WebVTT
.webmmoviesWebM is an audiovisual media file format. It is primarily intended to offer a royalty-free alternative to use in the HTML5 video and the HTML5 audio elements. https://en.wikipedia.org/wiki/WebM
.ogvmoviesTheora is a free lossy video compression format. It is is most commonly used in conjunction with the Ogg container format. https://en.wikipedia.org/wiki/Theora
.md5moviesThe MD5 message-digest algorithm is a cryptographically broken but still widely used hash function producing a 128-bit hash value. https://en.wikipedia.org/wiki/MD5
.mkvmoviesThe Matroska Multimedia Container is a free and open container format, a file format that can hold an unlimited number of video, audio, picture, or subtitle tracks in one file. https://en.wikipedia.org/wiki/Matroska
.m4vmoviesThe M4V file format is a video container format developed by Apple and is very similar to the MP4 format. The primary difference is that M4V files may optionally be protected by DRM copy protection. https://en.wikipedia.org/wiki/M4V
.movmoviesQuickTime is a video format that is particularly suited for editing, as it is capable of importing and editing in place (without data copying). https://en.wikipedia.org/wiki/QuickTime_File_Format
.mpeg4moviesMPEG-4 is a method of defining compression of visual (AV) digital data. https://en.wikipedia.org/wiki/MPEG-4
.mpegmoviesMPEG-2 is a standard for “the generic coding of moving pictures and associated audio information”. https://en.wikipedia.org/wiki/MPEG-2
.mpgmoviesMPEG-2 is a standard for “the generic coding of moving pictures and associated audio information”. https://en.wikipedia.org/wiki/MPEG-2
512kb.mp4moviesLow resolution MPEG4 video file
thumb.jpgmoviesImages of video captured approximated every 30 seconds. They are used in the player scrubber
ia.mp4moviesDerived h.264 file intended to create web-friendly version of uploaded source mp4 that does not meet the minimum criteria for optimal use in the online media player.
cc5.txtmoviesClosed captions text file captured with tv archive recordings
align.srtmoviesClosed Captions in TV Archive items adjusted to better align with the AV
cc5.srtmoviesClosed Captions in TV Archive items
.avimoviesCinepak is a lossy video codec developed by Peter Barrett at SuperMac Technologies, and released in 1991 with the Video Spigot, and then in 1992 as part of Apple Computer’s QuickTime video suite. https://en.wikipedia.org/wiki/Cinepak
asr.jsmoviesAutomatic Speech Recognition closed captions. Computer generated from mp3 audio files that are converted to text files.
asr.srtmoviesAutomatic Speech Recognition closed captions formatted to run in conjucntion with the related video file. Computer generated from mp3 audio files that are converted to text files.
.mp4moviesAdvanced Video Coding (AVC), also referred to as H.264 or MPEG-4 Part 10, Advanced Video Coding (MPEG-4 AVC), is a video compression standard based on block-oriented, motion-compensated coding. https://en.wikipedia.org/wiki/Advanced_Video_Coding
.wmvmoviesAdvanced Systems Format (wmv) is Microsoft’s proprietary digital audio/digital video container format, especially meant for streaming media. https://en.wikipedia.org/wiki/Advanced_Systems_Format
h.264 720Pmovies720px1080p h.264 file. Advanced Video Coding (AVC), also referred to as H.264 or MPEG-4 Part 10, Advanced Video Coding (MPEG-4 AVC), is a video compression standard based on block-oriented, motion-compensated coding. https://en.wikipedia.org/wiki/Advanced_Video_Coding
h.264 HDmovies720px1080p h.264 file. Advanced Video Coding (AVC), also referred to as H.264 or MPEG-4 Part 10, Advanced Video Coding (MPEG-4 AVC), is a video compression standard based on block-oriented, motion-compensated coding. https://en.wikipedia.org/wiki/Advanced_Video_Coding
.xmlmoviesTV Archive minimal metadata to create full metadata for a show (eg: program title & description, scheduled duration, etc.)
h.264 popcornmoviesOnline directly in-the-browser user edited audio/video editor files that will playback arbitrary audio & video files, add textual overlays, maps, and more as well
thumb.jpgmoviesA smaller version of various item image files
align.jsonmoviesCaptions alignment (audio wave form vs. captions) to reduce the “drift” between what is spoken vs. what got captioned. They can often have 2-10 seconds of distance between displayed words/captions and heard audio
rules.confmovies/audioPrevents lossy derivatives of source data files in audio and video items
.apksoftwareThe Android Package with the file extension apk is the file format used by the Android operating system, and a number of other Android-based operating systems for distribution and installation of mobile apps, mobile games and middleware. https://en.wikipedia.org/wiki/Apk_(file_format)
screenshot.pngsoftwareScreen capture of an emulated computer game
.dmgsoftwareApple Disk Image is a disk image format commonly used by the macOS operating system. When opened, an Apple Disk Image is mounted as a volume within the Finder. https://en.wikipedia.org/wiki/Apple_Disk_Image
.ipasoftwareAn .ipa (iOS App Store Package) file is an iOS application archive file which stores an iOS app. https://en.wikipedia.org/wiki/.ipa
.adfsoftwareAmiga Disk File (ADF) is a file format used by Amiga computers and emulators to store images of floppy disks. https://en.wikipedia.org/wiki/Amiga_Disk_File
.scrsoftwareA screensaver is a computer program that blanks the display screen or fills it with moving images or patterns, when the computer has been idle for a designated time. https://en.wikipedia.org/wiki/Screensaver
.logtextsThere are several logs from scanning, republishing, etc. e.g. Cloth Cover Detection Log, various Republisher Logs, and then the plan Log format for Scribe logs.
.pdftextsThe presentation version on BHL in PDF format. Low quality; sufficient for printing and reading text
reviews.xmltextsThe meta.xml file contains all of the item-level metadata for reviews
meta.xmltextsThe meta.xml file contains all of the item-level metadata for an item (e.g. title, description, creator, etc.).
marc.xmltextsthe MARC (bibliographic description) data in XML. MARC is a bibliographic data format describing standards for the representation and communication of bibliographic and related information in machine-readable form, and related documentation
meta.mrctextsthe binary MARC record as retrieved using z39.50. MARC is a bibliographic data format describing standards for the representation and communication of bibliographic and related information in machine-readable form, and related documentation
orig_jp2.tartextsSome books are so large that the volume of images exceed the maximum size for a ZIP archive. For these books, the images are compressed and delivered using TAR. These TAR archives average 2.07 gb and occur .39% of the time (738 out of 191,568 books total). High quality; Best for use and printing of plates, illustrations, detailed figures and tables
.djvutextsSimilar to PDF, a proprietary compressed document format.Low quality; sufficient for printing and reading text
scandata.xmltextsScandata is an XML file containing specific per-image information, including if the image should be included in any of the produced formats. The module will find, parse and honors these files if they exist.
.pdftextsPortable Document Format files, containing MRC-compressed images and the OCR result as a hidden (selectable, searchable) text layer. (In some cases, the PDF files can have a slightly different suffix, but the extension remains .pdf)
itemimage.pngtextsPNG image file to be used as the main image in an item page. For audio items it may appear adjacent to the audio player. For collection items it will appear adjacent to the title. It will be used to create the thumbnail image that is used in search results tiles.
chocr.html.gztextsOCR results with character-level granularity
dc.xmltextsOAI record in Dublin Core (bibliographic description) XML. Dublin Core is a set of metadata elements that provide a small and fundamental group of text elements through which most resources can be described and cataloged; a metadata format for describing resources.
meta.sqlitetextsMetadata for file sync via an sqlite database
names.xmltextslist, by page, of all the scientific names found in the book; presented in xml format
itemimage.jpgtextsJPG image file to be used as the main image in an item page. For audio items it may appear adjacent to the audio player. For collection items it will appear adjacent to the title. It will be used to create the thumbnail image that is used in search results tiles.
__ia_thumb.jpgtextsItem thumbnail image used in search results tiles
abbyy.gztextsGZipped version of the full ABBYY FineReader XML output, which includes all character-level information (confidence, location, etc.)
itemimage.giftextsGIF image file to be used as the main image in an item page. For audio items it may appear adjacent to the audio player. For collection items it will appear adjacent to the title. It will be used to create the thumbnail image that is used in search results tiles.
.epubtextsEPUB is an e-book file format that uses the “.epub” file extension. The term is short for electronic publication and is sometimes styled ePub. EPUB is supported by many e-readers, and compatible software is available for most smartphones, tablets, and computers.
textsDigital accessible information system (DAISY) is a technical standard for digital audiobooks, periodicals, and computerized text. DAISY is designed to be a complete substitute for print material and is specifically designed for use by people with “print disabilities”, including blindness, impaired vision, and dyslexia. https://en.wikipedia.org/wiki/Digital_Accessible_Information_System
archive.torrenttextsDerived torrent file that contains files information on files in an item. archive.org does not seed files.
encrypted.pdftextsDerived encrypted PDF file for use in DRM reader apps such as Adobe Digital Editions
encrypted.epubtextsDerived encrypted EPUB file for use in DRM reader apps such as Adobe Digital Editions
slip.pngtextsBook scanning slips that get uploaded to reserve an identifier so as not to have to wait hours for a full book to upload
hocr.htmltextsBarring any failures in the OCR process, after upload, every item will get one or more hocr.html files which represent the results of OCR jobs. Each hocr.html file contains results for all pages in one set of images (book, PDF, or otherwise), with text, bounding boxes, and confidence at the word level. For those seeking more detailed OCR results, each _hocr.html file should also have a corresponding chocr.html.gz file, with character-level granularity. (The exact meaning of “character” differs, of course, per script or language).
images.ziptextsA zip imagestack file formatted to derive the files necessary to create a flip book, pdf and other text formats
jp2.ziptextsA ZIP archive of all of the cleaned, cropped, etc. JP2 page images. These are the highest quality, least modified images that are available after the raw/orig file set. High quality; Best for use and printing of plates, illustrations, detailed figures and tables
jp2.tartextsA tar imagestack file formatted to derive the files necessary to create a flip book, pdf and other text formats
hocr_pageindex.json.gztextsa simple JSON array annotating where each individual page element starts in the hocr.html file, enabling quick fast-forwarding to an individual page without parsing all the XML.
metasource.xmltextsa proprietary XML file recording where the MARC record came from (catalog, operator, zquery, etc.) MARC is a bibliographic data format describing standards for the representation and communication of bibliographic and related information in machine-readable form, and related documentation
scandata.xmltextsa proprietary XML file recording information about each page image (handSide, cropBox, original width & height, etc.)
hocr_searchtext.txt.gztextsa plaintext file that is ingested by the full text search engine.
djvu.xmltextsa modified version of the DjVu XML standard, these files can also be used to read OCR results, but the recommendation is to instead parse the hOCR files.
page_numbers.jsontextsA map of page numbers auto-detected in a book. If the confidence score is high enough, they are sometimes added to scandata.xml
events.jsontextsA json file containing information about Republisher events. The format is deprecated and no longer used
djvu.txttextsa human-readable plaintext version of the generated djvu.xml file. OCR stands for “Optical Character Recognition;” the conversion of images of text into text characters
bhlmets.xmltextsA format created and used by Biodiversity Heritage Library (BHL)
.cbrtextsA comic book archive or comic book reader file (also called sequential image file) is a type of archive file for the purpose of sequential viewing of images, commonly for comic books. https://en.wikipedia.org/wiki/Comic_book_archive
.cbztextsA comic book archive or comic book reader file (also called sequential image file) is a type of archive file for the purpose of sequential viewing of images, commonly for comic books. https://en.wikipedia.org/wiki/Comic_book_archive
bw.pdftextsA black and white PDF compiled using binarized versions of the images. The binarized images are not made available. Low; sufficient for printing with low cost of ink or printing only text images
.mobitexts.mobi is an e-book file format that is primarily used for Kindle e-readers. https://en.wikipedia.org/wiki/Mobipocket
.warcwebThe Web ARChive (WARC) archive format specifies a method for combining multiple digital resources into an aggregate archive file together with related information. https://en.wikipedia.org/wiki/Web_ARChive
warc.gzwebA compressed Web ARChive (WARC) archive using gzip,a file format and a software application used for file compression and decompression. The format specifies a method for combining multiple digital resources into an aggregate archive file together with related information. https://en.wikipedia.org/wiki/Web_ARChive

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