Fata-Morgana

How to build

Framework depends on fmpeg and freetype2, so you need to have them installed. For ocaml part you need to install ctypes and ctypes-foreign Build framework with command make. To run test run make run.

How to use

Import framework

module Fm = Fata_morgana

Create video scene with

let scene = Fm.init "video.mpeg" 720 480 in

Only mpeg4 format with h264 encoding is supported for now

In module Fata-morgana there is a type

type fmbox = float * float * float * float

type fontsize =
| Small
| Medium
| Big

type fmaction =
| Text of string*fmbox*fontsize
| Circle of float*float*int*int*float
| Background

You can create a sequence of actions with <~ operator

    let sq = []
    <~ Fm.addBackground
    <~ Fm.addText problem middleBox Medium in

and then pass it to another procedure, that takes scene, action list and time

    Fm.visualise_scene v sq 3.;

write and close video

    Fm.write_and_close v;

Colors are represented by their indicator functions that starts with names in lower case, for example dark0, red etc.

How to change colors

Just add your color to the front of the list of colors. Scene for now is just a product type of list of colors and pointer to C structure. Colors are added with corresponding type constructor, Dark0, Red etc. Color should be in yuv format. There is Color.rgb_to_yuv to help you with convertion.

How to write your animation

Write a function in ZIG in that takes visual parameters and which frame from animation is drawn. Then add type to fmaction in fmaction and add call of c function to function do_action.

How library is structured

Framework is powered by avlib library which is a part of FFMPEG. The video data is stored in a single data structure FMVideo most other functions operates on a single instance of FMVideo.

Ocaml's part

• init function allocates memory for fmvideo and returns a product of video and colorscheme

To do list

• move from dynamic library to static
• function that takes parametres and sais how much space line will take
• tabels (precalculated in ocaml??)
• font sizing
• more boxes
• setting fonts
• positioning dependind on center etc
• fix font rendering (border colors are terrible)
• write latex parser
• not pessimisation (add caching)
• optimization (add simd)
• gpu acceleration (maybe one day)
• better errors
• remove dependence on others libraries