Pandoc

Everyone I know who works with markup languages says Pandoc is the go-to utility for converting between those languages. And for good reason: Pandoc not only does some pretty nifty conversions, it’s fast, too.

Have a file formatted with Markdown that you want to convert to a LibreOffice Writer document? How about a LaTeX document that you want to turn into an EPUB? Or maybe you have an HTML file that you want to turn into a slide deck. Pandoc is up to all of those tasks. And more.

Here’s how to use Pandoc for a simple conversion (in this case, from HTML to reStructuredText):

pandoc -t rst myFile.html -o myFile.rst

You’re not just limited to straight conversions. You can, for example, add a table of contents, typographic quotes, custom headers, and syntax highlighting to the resulting file. Take a peek at Pandoc’s documentation for details.

Pandoc, however, only handles text-based files. What happens if you have a binary file, such as a word processor document? Help at the command line comes from an unexpected source.

LibreOffice

You’re probably thinking, “Hold on! LibreOffice is a GUI application.” Yes, it is. But what many people don’t know is that you can run LibreOffice from the command line to quickly convert one or more files.

How? To, for example, transform a LibreOffice Impress slide deck to PDF, you’d type the following:

soffice --headless --convert-to pdf mySlides.odp

You’d just replace pdf with the extension of whatever file format you want to convert to. The --headless option, in case you’re wondering, stops an empty LibreOffice window from opening on your desktop.

Using LibreOffice at the command line to convert a single file is overkill. However, turning to the command line is a great way to convert several files at once. If, say, you want to convert all of the Microsoft Word documents in a folder to LibreOffice Writer format, you’d type:

soffice --headless --convert-to odt *.docx

The conversion takes far less time than opening all of those files in LibreOffice Writer and doing the conversion manually.

FFmpeg

Whereas Pandoc is the Swiss Army Knife for converting between markup languages, FFmpeg is Pandoc’s opposite number for audio and video formats.

FFmpeg is a set of libraries and executables that give you the ability to convert seemlessly between nearly any format.

Here’s an example of a simple conversion of a video from AVI to Ogg Theora:

ffmpeg -i myVideo.avi myvideo.ogg

FFmpeg can do a lot more than that. You can set the frame rate of videos and add subtitles to them, change the aspect ratio, change the quality of audio, and more.

The command line can get quite crowded with those options, should you choose to use more than a couple of them. It’s easy to forget the options, especially if you only use FFmpeg every so often. Take it from an old technical writer: There’s no shame in reading the documentation.

H/T: Opensource.com  https://opensource.com/life/16/10/3-file-conversion-tools-linux-command-line?sc_cid=701600000011te3AAA