preziscraper

This is a little tool written in Node.JS to download and convert a Prezi presentation into a pdf.

Why create this?

One of my lecturers created his lecture in Prezi and I wanted to work with it on my iPad. Unfortunetaly, Prezi won't let you download their slide sets as PDF unless you have a Pro Account which is ridiculous and way too expensive.

So I created this Prezi scraper that lets me download the Prezi slides and convert them into a single PDF file.

Requirements

You need a chromium browser (e.g. Google Chrome) installation on your pc.

Alternatively you can change puppeteer-core to puppeteer in [preziscraper.js](preziscraper.js)

Installation

Simply clone this package and run npm install.

Using this tool

Currently, the tool is split into two scripts. [preziscraper.js](preziscraper.js) contains the scraper, while [imgtopdf.js](imgtopdf.js) contains the pdf creation tool, to make a pdf out of the scraped Prezi slides.

If I find the time, I will merge them into one script.

Scrape Prezis

To scrape a Prezi and save them as images, simply run node preziscraper.js --url [PREZI URL]

Additional options are:

• --width to set the width [default is 595]
• --height to set the height [default is 842]
• --out to set the output folder of the scraped Prezi slides [default is img in the repo folder]
• --chromePath to set the path to the chromium executable [default is C:\\Program Files (x86)\\Google\\Chrome\\Application\\chrome.exe for windows and /usr/bin/google-chrome for everything else]

Transform Prezi Slides to PDF

To transformt the scraped Prezi to PDF, run node imgtopdf.js.

Additional options are:

• --in to set the input folder [default is ./img in the repo folder]
• --out to set the output path [default is ./prezi.pdf in the repo folder]
• --del add this flag to delete all previously scraped images after the convertion is done

How it works

The script uses puppeteer to control chromium, in order to access the Prezi. It will then go over each slide and take a screenshot.

In the end the images of the Prezi slides can be converted to a single PDF file.

Issues

Transition

Currently the script does not detect when a transition is done. I therefore hardcoded a timeout of 1200 ms in [preziscraper.js](preziscraper.js). However, there is a chance that if the transition takes to long, e.g. when transitioning from an overview to a slide, the screenshot will be taken while the actual slide is not yet zoomed in.

Full Screen

When [preziscraper.js](preziscraper.js) is being run in headless mode, it will not go into full screen mode for some reason. Needs to be investigated.