SlideXtract

A tool to help extract slides from a video file.

Slides are output in the out folder.

Features

I didn’t find any other piece of code that did all the stuff I wanted, so I’ll talk about some of the unique things about my code:

  • Customizable interval between frames, so you don’t end up extracting every single frame in the video.
  • Customizable threshold distance to help differentiate between slides. Can be adjusted to fit your video better.
  • Parallel processing while extracting frames from video
  • Batch processing

Requirements

  • ffmpeg and ffprobe on PATH.

Usage

Usage: slidextract --path PATH [--interval INTERVAL] [--threshold THRESHOLD] [--workers WORKERS] [--format FORMAT] [--batch BATCH]

Options:
  --path PATH, -i PATH   Path to video.
  --interval INTERVAL, -t INTERVAL
                         Time between frames. [default: 0.5s]
  --threshold THRESHOLD, -d THRESHOLD
                         Threshold distance to recognize as different frame. [default: 10000]
  --workers WORKERS, -w WORKERS
                         Number of processes to run parallelly. [default: 8]
  --format FORMAT, -f FORMAT
                         File format of output slides. Allowed values are: bmp (fastest), png (slowest) and jpg/jpeg. [default: bmp]
  --batch BATCH, -b BATCH
                         Describes if Path is a path to a folder of videos. [default: 0]

For some reason the bmp format is fastest, and the png format is slowest. This probably has something to do with codecs, and how ffmpeg handles stuff. This has been tested on a real lecture (about an hour long) with a 5 second interval between frames.

Slides are output in the out folder.

Why?

Every single day I lose another bit of my sanity. I am on the brink of losing it.

Turns out, some professors will use a presentation in class, but will refuse. I REPEAT, REFUSE TO GIVE YOU THE SLIDES. THEY’LL UPLOAD A RECORDING OF THE LECTURE BUT WILL REFUUUUUUUSE TO UPLOAD THE SLIDES.

So, I made this. Have fun 🙂

Unis will do anything in their power to cause you maximum pain. I hope this relieved some of it.

Contribution

So far, some things we can improve on:

  • Speeding up frame extraction if possible
  • Speeding up the algorithm by which we find distance between frames
  • Alternate image distance algorithms
  • Hardware acceleration support for ffmpeg

If you have more ideas, feel free to open a PR/Issue!

GitHub

View Github