# Commands for converting documents This file contains commands for converting different document types into * text (for fulltext search) * png (for preview images) * pdf (for pdf documents) Such conversions may not necessarily output an excact equivalent of the input file, but outputs a suitable representation, e.g. converting an mp3 file into text may output the metadata or even the lyrics of the song. Converting it into a preview image may result in a picture of the album cover. Please note, that when ever a command outputs anything to stderr, this will considered as a failure of the command. Most command line programs have a parameter (.e.g. `-q`) to suppress such an output. If you run php-fpm you may encounter problems with charsets based on UTF-8. Programms like `catdoc` read LANG from the environment to set the correct encoding of the output. php-fpm often clears the environment and programms like `catdoc` will not longer output any UTF-8 chars. In such a case you may want to set `clear_env=no` in php-fpm's configuration. On Debian this is done in the file `/etc/php//fpm/pool.d/www.conf`. Search for `clear_env`. ## Conversion to text for fulltext search ### text/plain, text/csv, application/csv `cat '%s'` ### application/pdf `pdftotext -q -nopgbrk %s - | sed -e 's/ [a-zA-Z0-9.]\{1\} / /g' -e 's/[0-9.]//g'` If pdftotext takes too long on large document you may want to pass parameter `-l` to specify the last page to be converted. `-q` is for suppressing error/warnings send to stderr `mutool draw -F txt -q -N -o - %s ` ### application/vnd.openxmlformats-officedocument.wordprocessingml.document `docx2txt '%s' -` ### application/msword `catdoc %s` ### application/vnd.oasis.opendocument.text `odt2txt %s` ### application/vnd.openxmlformats-officedocument.spreadsheetml.sheet `xlsx2csv -d tab %s` ### application/vnd.ms-excel `xls2csv -d tab %s` ### text/html `html2text %s` Many office formats can be converted with `unoconv`, though this turned out in the past to sometimes crash or taking a long time. `unoconv -d document -f txt --stdout '%s'` Apache Tika is another option for creating plain text from various document types. Just use `curl` to send the document to your tika server and get the plain text in return. `curl -s -T '%s' http://localhost:9998/tika --header 'Accept: text/plain'` Of course this requires to first install Apache Tika when using the docker image. ## Conversion to pdf for pdf preview * text/plain, text/csv, application/csv, application/vnd.oasis.opendocument.text application/msword, application/vnd.wordperfect, text/rtf `unoconv -d document -f pdf --stdout -v '%f' > '%o'` * image/png, image/jpg, image/jpeg `convert -density 300 '%f' 'pdf:%o'` Actually `convert` can be used for many other image formats. * image/svg+xml `cairosvg -f pdf -o '%o' '%f'` * application/vnd.ms-powerpoint, application/vnd.openxmlformats-officedocument.presentationml.presentation, application/vnd.oasis.opendocument.presentation `unoconv -d presentation -f pdf --stdout -v '%f' > '%o'` * application/vnd.ms-excel, application/vnd.openxmlformats-officedocument.spreadsheetml.sheet, application/vnd.oasis.opendocument.spreadsheet `unoconv -d spreadsheet -f pdf --stdout -v '%f' > '%o'` * message/rfc822 `java -jar emailconverter-2.5.3-all.jar '%f' -o '%o'` The emailconverter can be obtained from https://github.com/nickrussler/email-to-pdf-converter It requires `wkhtmltopdf` which is part of debian. * text/plain `iconv -c -f utf-8 -t latin1 '%f' | a2ps -1 -q -a1 -R -B -o - - | ps2pdf - -` The parameter `-q` is important because a2ps sends some statistical data to stderr, which makes SeedDMS believe the command has failed. * application/x-xopp `xournalpp -p "%o" "%f"` Converting from application/x-xopp to pdf only works if the xopp file does not use a pdf document as a background, because this pdf is not stored in the xopp fіle. ## Conversion to png for preview images If you have problems running convert on PDF documents then read the page https://askubuntu.com/questions/1081895/trouble-with-batch-conversion-of-png-to-pdf-using-convert It basically instructs you to comment out the line in /etc/ImageMagick-6/policy.xml `convert` determines the format of the converted image from the extension of the output filename. SeedDMS usually sets a propper extension when running the command, but nevertheless it is good practice to explicitly set the output format by prefixing the output filename with 'png:'. This is of course always needed if the output goes to stdout. ### image/jpg, image/jpeg, image/png `convert -resize %wx '%f' 'png:%o'` * image/svg+xml `cairosvg -f png --output-width %w -o '%o' '%f'` * text/plain `convert -density 100 -resize %wx 'text:%f[0]' 'png:%o'` * application/pdf `gs -dBATCH -dNOPAUSE -sDEVICE=png16m -dPDFFitPage -r72x72 -sOutputFile=- -dFirstPage=1 -dLastPage=1 -q '%f' | convert -resize %wx png:- '%o'` `convert -density 100 -resize %wx '%f[0]' 'png:%o'` `mutool draw -F png -w %w -q -N -o '%o' '%f' 1` `pdftocairo '%f' -png -singlefile -scale-to-x %w -scale-to-y -1 - > '%o'` `pdftocairo` needs to output to stdout because the output file name passed to pdftocairo will be suffixed with `.png` * application/postscript `convert -density 100 -resize %wx '%f[0]' 'png:%o'` * text/plain iconv -c -f utf-8 -t latin1 '%f' | a2ps -1 -q -a1 -R -B -o - - | gs -dBATCH -dNOPAUSE -sDEVICE=png16m -dFirstPage=1 -dLastPage=1 -dPDFFitPage -r72x72 -sOutputFile=- -q - | convert -resize %wx png:- 'png:%o' On Linux systems you will have to set the desired value in /etc/papersize for a2ps e.g. a4, or letter. Unfortunately, a2ps cannot process utf-8 encoded files. That's why the input needs to be recoded with iconv or recode. * application/msword, application/vnd.oasis.opendocument.spreadsheet, application/vnd.oasis.opendocument.text, application/vnd.openxmlformats-officedocument.spreadsheetml.sheet, application/vnd.ms-excel, application/vnd.openxmlformats-officedocument.wordprocessingml.document, text/rtf, application/vnd.ms-powerpoint, text/csv, application/csv, application/vnd.wordperfect, `unoconv -d document -e PageRange=1 -f pdf --stdout -v '%f' | gs -dBATCH -dNOPAUSE -sDEVICE=pngalpha -dPDFFitPage -r72x72 -sOutputFile=- -dFirstPage=1 -dLastPage=1 -q - | convert -resize %wx png:- 'png:%o'` * video/webm, video/mp4 This will take 12th frame of a video and converts into a png. It requires ffmpeg to be installed. `convert -resize %wx "%f[12]" "png:%o"` You may as well use ffmpeg right away `ffmpeg -i "%f" -ss 00:00:02 -frames:v 1 -loglevel quiet -vf scale=%w:-1 -f apng "%o"` * audio/mpeg `sox "%f" -n spectrogram -x 600 -Y 550 -r -l -o - | convert -resize %wx png:- "png:%o"` * application/x-xopp `xournalpp -i "%o" --export-png-width=%w "%f"` Converting from application/x-xopp to png only works if the xopp file does not use a pdf document as a background, because this pdf is not stored in the xopp fіle.