scientiaetveritas/myslideslive

Extract your SlidesLive presentation.

mySlidesLive

...helps you to extract your SlidesLive presentation.

Install

pip install myslideslive

Usage

Python

In a Python console:

from myslideslive import SlidesLive

msl = SlidesLive('https://slideslive.com/38956531/'
                 'beyond-static-papers-'
                 'rethinking-how-we-share-scientific-understanding-in-ml')
msl.download_slides(slide=(1074, 1075))
msl.compose_video()

CLI

Directly from terminal:

msl --slide 1074 1075 \
https://slideslive.com/38956531/beyond-static-papers-rethinking-how-we-share-scientific-understanding-in-ml

Development

• To develop this package you need nbdev.
• The library (and Makefile) is built with nbdev_build_lib.
• nbdev_update_lib updates the notebooks based on changes in the library.
• The README.md is regenerated with nbdev_build_docs.
• The git hooks are set up with nbdev_install_git_hooks.

Before commiting code changes make sure to run:

nbdev_install_git_hooks && \
nbdev_build_lib && \
nbdev_build_docs && \
nbdev_clean_nbs --clear_all True && \
nbdev_test_nbs

What about the SlidesLive video recording?

If you want to get the video recording of your SlidesLive presentation as well, youtube-dl can take care of that.

Cutting the video

Then you can cut the video with:

ffmpeg -i video_in.mp4 -ss [start] -t [duration] -c copy video_out.mp4

where [start] specifies the start time, e.g. 00:01:23.000 or 83 (in seconds); and [duration] specifies the duration in the same format. Alternatively to -t [duration], you may use -to [end], i.e.:

ffmpeg -i video_in.mp4 -ss [start] -to [end] -c copy video_out.mp4

NOTE: the order of ffmpeg flags seems to influence the precision of the video cut.

Picture-in-Picture embedding

To embed the video recording within the bottom-right part of the presentation video, preserving the audio stream from the former use:

ffmpeg -i embedded_video.mp4 -i main_video.mp4 \
  -filter_complex "[0] scale=iw/10:ih/10 [embed]; \
                   [1] fps=25 [bg]; \
                   [bg][embed] overlay=main_w-overlay_w:main_h-overlay_h" \
  -framerate 25 \
  -b:v 4810k \
  -b:a 126k \
  -ar 44100 \
  PiP_video.mp4

The sound stream is always taken from the first video in the input (-i) list; if you swap the input videos, you also need to swap [0] and [1] in the filter string (-filter_complex). To move the embedded video to a different position, you need to change the overlay parameter. For example, overlay=main_w-overlay_w:0 will place the embed in the top-right corner; overlay=0:0 in the top-left; and overlay=0:main_h-overlay_h in the bottom-left.

About

This Python module was inspired by:

• https://github.com/Chandrahasd/slideslive-slides-dl; and
• https://github.com/AugustKarlstedt/slideslive-downloader.

PiP ffmpeg command comes from here.