dragonflies with birds and python

This is a ~~silly~~ pretty basic video editing library that stands on top of ffmpeg. Also has it's own scripting language and interpreter called tiva to ease the job of editing video.

Why the name?

This project started as an attempt to investigate about color spaces inspired by Wolfgang Lehmann's Dragonflies with birds and snake video.

Motivation

Simply because the video editors that I've found for GNU/Linux didn't addressed my (basic) needs:

cut
paste
avoid crashing

So I ended writing some sort of DSL-ish library to work with ffmpeg. Then I remembered about MoviePy, a fantastic Python module to edit videos. ¯\_(シ)_/¯.

What's tiva?

tiva stands for tiva isn't video art. Is the interpreter that parses .tv code in order to manipulate videos.
The .tv code is pretty simple since it only has 4 verbs: cut, paste, blend, and apply. Each verb has a set of arguments to perform the action:

`cut`

Simply cuts chunks of a video.

using determines the video input
start determines the starting point to cut
duration determines the length of the video
render determines the video output

cut
{
    using "video_test.mp4"
    start "00:00:00"
    duration "00:00:10"
    render "video_cut.mp4"
}

`paste`

Appends videos into one.

using determines the video input, since it glues together more than one video one needs to pass more than one video separated by a space
render determines the video output

paste
{
    using "video_a.mp4" "video_b.mp4"
    render "video_paste.mp4"
}

`blend`

Instead of appending, it will blend the videos together one on top of the other. Finishes when the longest video ends.

using determines the video input, since it blends together more than one video one needs to pass more than one video separated by a space
render determines the video output

blend
{
    using "video_a.mp4" "video_b.mp4"
    render "video_blend.mp4"
}

`apply`

Applies ffmpeg filters to the video. It's possible to pass more than one filter at a time.

using determines the video input
fx determines the filters to be applied
render determines the video output

# Just one filter
blend
{
    using "video_a.mp4"
    fx "reverse"
    render "video_reverse.mp4"
}

# More than one filter
blend
{
    using "video_a.mp4"
    fx "reverse" "blur"
    render "video_reverse_blur.mp4"
}

The valid filters are separated in two categories: with-arguments and without-arguments.
Without-arguments:

mirror, applies a mirror effect
greyscale, converts to b/w
sepia, converts to sepia
vintage, gives a vintage look
wires, it draws the border of the objects
paint, gives a painting look
negative, inverts the color
hflip, horizontal flip
vflip, vertical flip
kern, kernel deinterling
burning, gives a burned effect
negalum, inverts the colors but based on its luminance
noise, adds noise
reverse, goes backwards
portrait, changes the video from landscape to portrait
vignette, adds a vignette to the video
zoom, zooms from the center

With-arguments:

blur, simple Blur. By default it has a ratio of 5
magnify, magnifies a video. By default 2x
random, randomises frames of a video. By default, every 8 frames
overlay, shuffles the video. By default every 8 frames
tblend, blends frames (similar to the GIMP of Photoshop), valid values here
faster, speeds up the video. By default 2x
slower, slows down the video. By default 2x

lvm/dragonflies-with-birds-and-python