| --- |
| license: cc0-1.0 |
| pretty_name: E-book Format Samples |
| language: |
| - en |
| - es |
| - ru |
| size_categories: |
| - n<1K |
| tags: |
| - ebook |
| - file-format |
| - format-detection |
| - test-fixtures |
| - epub |
| - mobi |
| - fb2 |
| - lit |
| - lrf |
| - pdb |
| - text-extraction |
| configs: |
| - config_name: default |
| data_files: metadata.csv |
| --- |
| |
| # E-book Format Samples |
|
|
| Four public-domain books, each converted into up to 23 e-book and document formats: 88 files in total. |
| For every book there is also the XHTML source it was converted from and a plain-text ground truth, |
| so you always know what a file is supposed to contain. |
|
|
| ## Why this dataset |
|
|
| Legal sample files of old e-book formats are hard to find. Search for a LIT, LRF or TCR file and you mostly get |
| pirated books or files of unknown origin, with no idea what text is inside. Here the same known text exists in |
| every format, which makes the set useful for: |
|
|
| - **Testing format recognition.** File type detectors, MIME sniffing, ML classifiers of file types. Every row of |
| `metadata.csv` gives the extension, MIME type, first 16 bytes and, for Palm database based files, the type/creator code. |
| Several formats share a container (EPUB, KEPUB, DOCX, HTMLZ, TXTZ and PMLZ are all ZIP; MOBI, AZW3 and three PDB |
| flavours are all Palm databases), which is exactly where detectors get confused. |
| - **Developing converters and readers for rare formats.** LIT, LRF, TCR, SNB, RB, PMLZ, eReader, PalmDOC and zTXT |
| files with a text you can check against. Good for writing a new parser, fixing an old one or adding a format to an |
| existing reader. |
| - **Measuring text extraction.** Compare what your parser gets out of a file with `ground_truth/<book>.txt`. |
| Useful before feeding e-books into a search index or an LLM pipeline, where silent text loss is hard to notice. |
| - **Regression tests for reading apps.** Illustrations, a footnote, block quotes, scene breaks, a table of contents, |
| Cyrillic text, accented Spanish and a book made of several separate works. |
|
|
| ## Books |
|
|
| | id | Language | Text | Features | |
| |---|---|---|---| |
| | `alice_en` | English | Lewis Carroll, *Alice's Adventures in Wonderland*, chapters I-II (1865) | 2 illustrations by John Tenniel, italics, scene breaks | |
| | `art_of_war_en` | English | Sun Tzu, *The Art of War*, chapter I, translated by Lionel Giles (1910) | footnote, commentary as block quotes, numbered paragraphs | |
| | `quijote_es` | Spanish | Miguel de Cervantes, *Don Quijote de la Mancha*, chapters I-II (1605) | accented letters, ¡¿ punctuation, long chapter titles | |
| | `chekhov_ru` | Russian | Anton Chekhov, three short stories (1883-1884) | Cyrillic, dialogue dashes, non-breaking spaces, three works in one book | |
|
|
| ## Formats |
|
|
| | variant | Format | Extension | |
| |---|---|---| |
| | `epub2`, `epub3` | EPUB 2 and EPUB 3 | .epub | |
| | `kepub` | Kobo EPUB | .kepub | |
| | `azw3` | Kindle KF8 | .azw3 | |
| | `mobi7` | Mobipocket 6 (old MOBI) | .mobi | |
| | `mobi_joint` | MOBI + KF8 in one file | .mobi | |
| | `fb2` | FictionBook 2 | .fb2 | |
| | `lit` | Microsoft Reader | .lit | |
| | `lrf` | Sony BroadBand eBook | .lrf | |
| | `pdb_ereader`, `pdb_palmdoc`, `pdb_ztxt` | Palm database: eReader, PalmDOC, zTXT | .pdb | |
| | `rb` | RocketBook | .rb | |
| | `tcr` | Psion TCR | .tcr | |
| | `snb` | Shanda Bambook | .snb | |
| | `pmlz` | eReader PML in ZIP | .pmlz | |
| | `htmlz` | HTML in ZIP (Calibre) | .htmlz | |
| | `txtz` | text in ZIP (Calibre) | .txtz | |
| | `html_zip` | HTML in plain ZIP | .zip | |
| | `txt` | plain text, UTF-8 | .txt | |
| | `rtf` | Rich Text Format | .rtf | |
| | `docx` | Word | .docx | |
| | `pdf` | PDF | .pdf | |
|
|
| Missing on purpose: `rb` for the Spanish and Russian books, and `pdb_ereader` and `pmlz` for the Russian book (see below). |
|
|
| ## Layout |
|
|
| ``` |
| metadata.csv one row per file |
| files/<book>/<book>.<variant>.<ext> the samples |
| ground_truth/<book>.txt expected text of each book |
| source/<book>/<book>.html XHTML source (+ images) all formats were made from |
| ``` |
|
|
| `metadata.csv` columns: `file_name`, `book_id`, `language`, `format`, `variant`, `extension`, `mime`, |
| `text_encoding` (for 8-bit and text formats), `size_bytes`, `sha256`, `magic_hex` (first 16 bytes), |
| `pdb_type_creator` (bytes 60-67 of Palm database files, such as `BOOKMOBI`, `TEXtREAd`, `PNRdPPrs`), |
| `ground_truth`, `converter`, `options`, `roundtrip_word_recall`. |
|
|
| MIME types follow common practice. Formats without any widely used MIME type (TCR, SNB, PMLZ, HTMLZ, TXTZ) |
| are listed as `application/octet-stream`. |
|
|
| ## How the files were made |
|
|
| All files were produced from the XHTML sources with Calibre 9.17.0 (`ebook-convert`), chapters split on `<h2>`, |
| title, author, language and year set as metadata. The exact extra options for each file are in the `options` column. |
|
|
| - **8-bit formats.** PalmDOC and zTXT are written in cp1252 for the English and Spanish books and in cp1251 |
| for the Russian one (see `text_encoding`). Read them with that code page. |
| - **Gaps.** Calibre's PML writer, which is also used for eReader PDB, keeps only cp1252 and writes `?` for every |
| Cyrillic letter, so those two files are not included for the Russian book. Calibre also writes RocketBook files |
| for the Spanish and Russian texts that it cannot read back itself, so those were left out too. |
| - **Round-trip check.** Every file was converted back to text with the same Calibre and compared with the ground truth. |
| `roundtrip_word_recall` is the share of ground-truth words found in that text (lowest value in the set: 0.994). |
| It is a sanity check that the file really contains the book, not a benchmark of other tools. |
|
|
| Keep in mind that all samples come from one converter. Files made by the original vendor tools (Microsoft Reader, |
| Sony, Mobipocket Creator, Kindle) can use features and quirks that Calibre does not produce. |
|
|
| ## Ground truth |
|
|
| UTF-8 plain text: title, author, then each chapter title and its paragraphs, separated by blank lines. |
| The footnote reference is written as `[1]` and the note itself follows its chapter. Illustrations and scene |
| breaks carry no text. Non-breaking spaces are replaced with ordinary spaces. |
|
|
| ## Usage |
|
|
| ```python |
| from datasets import load_dataset |
| from huggingface_hub import hf_hub_download |
| |
| meta = load_dataset("Toolster/ebook-format-samples", split="train") |
| row = meta.filter(lambda r: r["variant"] == "lit")[0] |
| path = hf_hub_download("Toolster/ebook-format-samples", row["file_name"], repo_type="dataset") |
| truth = hf_hub_download("Toolster/ebook-format-samples", row["ground_truth"], repo_type="dataset") |
| ``` |
|
|
| ## Sources and license |
|
|
| - Texts: Project Gutenberg eBooks #11, #132 and #2000 (only the chapters themselves were taken, without the Gutenberg |
| header and license), and Russian Wikisource (Chekhov, Complete Works edition texts). |
| All are in the public domain. |
| - Illustrations: John Tenniel (1865), from Wikimedia Commons, public domain. |
| - The converted files, ground truth and metadata are released under CC0 1.0. |
|
|
