refactor tutorials

[ReimarBauer]

We should develop a base class for tutorials.

It contains all the basic functions that make up a tutorial.

and will be extended by a command line interface to start a tutorial,
e.g. different options:

• Show me how to do this (play)
• Record what you do. (play and record)

A single tutorial is derived from this base class.

The functions in the tutorials are stored in single modules and then imported for a new tutorial

The goal is that a user can formulate queries, and from these a tutorial is created.

E.g.

• Show me how to create an account,
• Show me how to log in and create an operation.

When the tutorial is compiled, it can be controlled with the execution options, e.g. play (play and record).

A number of tutorials get accessible from the help menu.

[ReimarBauer]

Played a bit with different posiblities of ffmpeg

slicing

ffmpeg -i input_wms.mp4 -ss 00:00:14 -to 00:04:03 -c:v libx264 -crf 30 -acodec mp2 input_wms2.mp4

cropping

ffmpeg -i input_wms2.mp4 -filter_complex "[0:v]crop=1920:1050:0:0[cropped]" -map "[cropped]" input_wms3.mp4

speeding result 22 Seconds

ffmpeg -i input_wms3.mp4 -filter:v "setpts=0.1*PTS" input_wms4.mp4

scale

ffmpeg -i input_wms4.mp4 -vf scale=1280:720 -preset slow -crf 18 input_wms5.mp4

convert to git (first idea)

ffmpeg -i input_wms5.mp4 input_wms5.gif

libx265

ffmpeg -i input_wms5.mp4 -vcodec libx265 -crf 28 input_wms6.mp4

convert to gif (no size change compared to libx264)

ffmpeg -i input_wms6.mp4 input_wms6.gif

using filter

ffmpeg -y -i input_wms6.mp4 -filter_complex "fps=5,scale=854:-1:flags=lanczos,split[s0][s1];[s0]palettegen=max_colors=32[p];[s1][p]paletteuse=dither=bayer" input_wms6.gif

This creates a 2.4MB gifcycle of the tutorial_wms rushing through the options in 22 sec

[ReimarBauer]

A first refactoring was already done. Here are some more ideas which might be interesting for a gsoc project