anibg

A script that will automatically resize a window of MPV to a resolution that will make it cover the entire computer screen, and then move this window to the same rendering layer as the desktop background image, in order to make it a living background. The scaling of the video file will be done so the aspect ratio is maintained, and the result will be centered in relation to the screen.

Acknowledgements and Thanks

This project was created after I got inspired by a Reddit post made by waicool20, who successfully managed to put a MPV window as a living background image. However, I found it rudimentary, and it used the old devilspie, so I took it upon myself to modernize it and make so that it automatically scaled the video to appropriate sizes.

Requirements

• bc (A calculator capable of floats)
• coreutils (Expected core utilities)
• devilspie2 (To execute actions on windows)
• ffmpeg/ffprobe (Media file information)
• MPV (Media player)
• sed (A stream editor)
• xdpyinfo (Screen information [for X])

Most of these packages are probably already installed on your system, but here is a one-liner to install them all on Debian 10.0 Buster:

sudo apt install bc coreutils devilspie2 ffmpeg mpv sed x11-utils

Installation

Begin by moving into a suitable directory and cloning this repository from GitHub.

git clone git@github.com:JonasAlfredsson/anibg.git

You should now be able to see two folders, and inside the src/ directory there will be two files that needs to be kept together for this script to work as intended. The anibg file is the main executable for this project, and it will source the utils file during runtime, so do not separate them.

Inside the configs/ folder you will find two .lua configuration scripts which should be moved to devilspie2's config folder (usually ~/.config/devilspie2/). The file called "MPV Wallpaper.lua" will then be updated by this program with values that makes the MPV window cover the entire screen. If the installation path is different it is important to update the corresponding variable at the top of the anibg script.

The other .lua file is just an empty placeholder to hinder devilspie2 from exiting with an error if it reads the real file while it is being edited. More info about this problem can be found inside the file.

Include in $PATH

After this, it should be possible to use this program by always providing the full path to the anibg file, but to be able to call the executable from anywhere on your system you can also add this repository's scr/ folder to your $PATH. This can be done by including the following line at the bottom of your ~/.bashrc or ~/.zshrc file.

PATH="/path/to/anibg/src:${PATH}"

By sourcing the edited file again, or just opening a new terminal, it should now be possible to use anibg without having to provide the full path.

Usage

To use this program you call on the anibg executable and provide a video file as the first and only argument. The script will then try to adjust the size of the MPV player's window to make sure the video stream covers the entirety of your screen before moving it to the background image layer. Here are some example commands:

/full/path/to/anibg /full/path/to/video.mp4

relative/path/to/anibg ../realative/path/to/video.mp4

And if you have the anibg executable in your PATH you can do this as well:

anibg realative/path/to/video.mp4

Configuration Options

At the top of the main anibg script file there exist four settings that can be changed by the user, accompanied with what values are valid.

dp2_conf - devilspie2's Config File

This should be the path to the .lua configuration file that is used by devilspie2 when resizing the video window of the MPV player. If you decided to place it somewhere else than ~/.config/devilspie2/ you can change it here.

automaticResolution - Automatic Resolution

If you have a special video file, that is not recognized correctly by the automatic resizing function, you can turn this functionality off and manually edit the MPV Wallpaper.lua file. Succeeding runs of anibg will then not perform any modifications to this config file, in order to not mess with your custom settings.

hwDecoder - Hardware Decoder

It is possible for MPV to use hardware accelerated decoding, of the video stream, on systems where this option is available. There are a couple of different setting combinations available, to achieve the best performance on different systems, but I have categorized them into four common scenarios for simplicity:

• none - Only use software decoding.
  • This will be compatible with all systems that have a CPU, but it will use a lot of system resources.
• auto - Let MPV find best decoder.
  • MPV is usually quite good at finding what options are available, and will most likely be able to automatically configure the decoder correctly by itself.
• intel - Use the Intel specific hardware decoder.
  • If the screen you are using is getting its signal from the integrated Intel graphics you can use this option, as it will use the hardware decoders available in the graphics part of the CPU instead.
• nvidia - Use the Nvidia specific hardware decoder.
  • If you have a Nvidia graphics card you can use this setting, as it will offload all the decoding to your dedicated graphics card instead.

If you are unsure what to use I would leave it at auto, but you can test the different settings while monitoring your system to find the one with best performance. For more information about this you can check out all the Hardware decoder options on the MPV site.

scaler - Scaler Algorithm

When scaling an image, or a video feed, some kind of algorithm is needed in order to calculate what color all the pixels in the resized variant should be. This is a complicated problem that has a quality/speed trade-off which you might need to take into consideration.

A system using software decoding might not have the necessary computing power to use the scaler that will produce the best quality results, and the video will play with a low frame rate as a result. The slowest decoder will most likely require a dedicated graphics card for acceptable performance on higher resolution video feeds.

For this script I have exposed three options for scalers (MPV has more available), with slower equating to better quality:

• fast - bilinear
  • Bilinear hardware texture filtering. This is the fastest scaler, but the quality is not that good. This is also MPV's default scaler for compatibility reasons.
• medium - spline36
  • This one has quite good quality at moderate resource requirements.
• slow - ewa_lanczossharp
  • This is a slightly sharpened version of another scaler called ewa_lanczos, and it is also using some additional pre-tuned parameters. If your hardware can run it, this is probably what you should use by default.

Like with the hardware decoder options, play around with the settings to see which one works best on your system. More information can be found in the Scaler options section on the MPV site.

Resources

The subreddit LivingBackgrounds is quite nice if you are looking for content to use as a living background, and so is the AA VFX YouTube channel. Beeple Crap has also some really nice animations, but you usually have to remove a couple of frames from the videos to have them loop seamlessly.

Furthermore, there are actually quite a few commands available for devilspie2 which can be used to manipulate windows on the system. The example here with MPV as a background image is just one option, and much more advanced actions can be performed if you take your time and read the instructions. More information can be found in the manual.

Other projects which I have looked at during my exploration into this area are wallama-paper, xwinwrap and SmartVideoWallpaper. I didn't feel like they were right for me, which is why I wrote my own script. However, they are all worth a look before you decide which one you want to use.