Categories
open source social

Create animated GIFs from MP4 with FFmpeg

Animated GIFs are after all these years still pretty popular. FFmpeg is a good FLOSS tool to create these animated GIFs. FFmpeg is available for Windows, Linux and OSX. A word of warning FFmpeg is a command line tool that’s very versatile but it’s not for everybody. In fact suppose this post is more for users that like to tinker a lot with their animated GIFs. Below I will explain not only how to create a animated GIF from an mpeg4 movie but I also provide instructions to improve the quality.

The basic command to create an animated GIF from a mpeg4 is:

ffmpeg -i input.mp4 output.gif

where the name of the input file is input.mp4 and output.gif is the name of the output file. Unfortunately gif images are large due to their lossless data compression. So you’ll end up with a file that’s much bigger than the original mpeg4 and probably something that exceeds the upload limit of Diaspora*, Friendica or Mastodon.

In order to reduce the size of the file we can reduce the size of the images or we can reduce the number of frames per second. To achieve this we need the following command:

ffmpeg -i input.mp4 -r 12 -s 320x180 output.gif

This command reduces the framerate to 12 per second and resizes to 320×180 pixels. For the size of the GIF make sure that the aspect ratio remains the same or the resulting GIF will be distorted.

When we look closely at the resulting GIF we clearly notice some shortcomings in the animation. This is due to the default GIF encoding in FFmpeg. Because GIFs only uses 256 colors the number of colors from the mpeg4 needs to be reduced. FFmpeg by default uses a generic palette of 256 colors that covers the widest range of content. This is in general not optimal for the specific video that you want to convert. Luckily FFmpeg allows us to create a custom palette for our specific video. To create this palette type:

ffmpeg -i input.mp4 -filter_complex "[0:v] palettegen" palette.png

When we look in the folder of our mpeg file well noice that a file ‘palette.png’ has been added. This is our newly created 256 color palette for our specific video which is generated by the palettegen filter. To use the new palette with our mpeg video type:

ffmpeg -i input.mp4 -i palette.png -r 12 -s 320x180 -filter_complex "[0:v][1:v] paletteuse" prettyOutput.gif

FFmpeg needs two input files (streams) in this case test.mp4 and our newly created palette.png. The paletteuse filter takes the two streams as input specified by [0:v] and [1:v] where v stands for video and the preceding number for the number of the stream. The output file is renamed to prettyOutput.gif to differentiate it from the earlier output.gif. The resulting video should be much … prettier. If your resulting video is still too large either reduce the frame rate or resize even further (or just reduce the length of the video of course).

Further reading:
http://blog.pkh.me/p/21-high-quality-gif-with-ffmpeg.html
https://engineering.giphy.com/how-to-make-gifs-with-ffmpeg/

Categories
open source PC

How to rip a DVD

Why in this day and age of Netflix one would be interested in how to rip a DVD? More and more people are using Netflix or an other video streaming service to watch movies and TV series. What most people don’t know is that Netflix is trampling user rights. Not only does Netflix use digital rights management (DRM) they also mine huge amounts of data from the users. This data is not only used to improve the service it can also be provided to third parties like law enforcement and other businesses for promotional ‘services’ . If you don’t believe me you can read it in the privacy statement of Netflix.

Unfortunately the’re very little legal alternatives that respect the user rights. DVD’s are an option but most of current DVD’s have strong DRM in place. Luckily this DRM can be removed with relatively simple means. Without the DRM the user can watch the content the way he/she prefers.

In this post I’ll explain what you need to remove the DRM from DVD’s and copy the movie or TV series to OpenELEC or LibreELEC or any other system with Kodi e.g in your living room.

Use original DVD’s

Don’t use pirated DVD’s. Let’s stick to what is legal. DVD’s are cheap and second hand DVD’s are even cheaper. For a few dollars/euros you can buy the best movies on DVD. Most DVD’s are protected with DRM and some publishers like Disney take severe measurements to prevent the user from making a copy for their own use. This is where Handbrake comes in.

Handbrake

Handbrake can, among other thing, read DVD’s and convert the content to e.g mpeg4 files. These mpeg4 files can than be stored on the HDD of a device of your liking and played with any media player. To be able to decrypt DRM protected DVD’s (see above) also a free/libre DVD playback library libdvdcss is needed. This article explains how to install this on Windows and OSX. And this article explains how libdvdcss works.

Screenshot of Handbrake
A screenshot of Handbrake. Handbrake reads a DVD and write the content to an mpeg4 file.

Handbrake tip

I was struggling to burn the subtitles into the media file that I created from a DVD. This is what eventually worked for me. When a DVD is opened and scanned, go to the subtitles tab, choose the preferred language and uncheck the Forced Only box while leaving the burned in box checked. That’s it. Now press the Start button to start encoding and your file should contain the burned-in subtitles with the language that you choose.

Under the Subtitles tab, select a language, keep the Forced On unchecked and Burned In checked.

MetaZ or MetaX

MetaZ is a metadata editor but the beauty is that it uses the title of the movie or the TV series to retrieve metadata from The Movie Database (TMDb) and adds this metadata to the rip file we just made with HandBrake. Unfortunately MetaZ only runs on OSX while MetaX only runs on Windows. Of course we can use VLC for GNU/Linux but the user has to add the metadata manually which is a pain in the butt.

Screenshot of MetaZ. With MetaZ you can add meta-data to a video file.

Kodi, OpenELEC, LibreELEC

Eventually you want to be able to play the video files that you ripped from the DVD’s. There are many free/libre software  choices but perhaps the most popular is Kodi.  Kodi is mediaplayer software that runs on about every media file you’ll throw at it. It is available for GNU/Linux, Windows and OSX. OpenELEC and LibreELEC take this a step further because they’re Linux based operating systems with the sole purpose to run Kodi.

Click here if you want about my experience with OpenELEC.

I hope this information has helped you to rip your DVD’s and start watching them on the device of your own liking. If you have any questions about this topic feel free to send me an email. Now if you excuse me I have a nice classic movie to watch.