After recording a video, you can use the following options:
Adding subtitles
You can add subtitles (transcriptions) to video steps. Here you can see an example: https://stepik.org/lesson/7560/step/1.
Adding can be done in the video step editing mode for those videos that were uploaded via a link or directly to Stepik.
Subtitles should be added in text form (SRT format, see https://matroska.org/technical/specs/ subtitles/srt.html и https://en.wikipedia.org/wiki/SubRip#SubRip_text_file_format). There are several programs and online services to create and edit SRT documents, e.g. http://subtitlefix.com/index.php.
Downloading a video
If you need to download all video materials from the entire course or module at the same time, please use the special Python script: https://github.com/StepicOrg/stepik-oauth2-videodownloader/blob/master/downloader.py/
Private keys can be obtained at https://stepic.org/oauth2/applications/register/. To do so, please log in to Stepik.org and register there, specifying “Client type: confidentialAuthorization Grant Type: client-credentials/”. After that you can launch python3 script with following command: python3 downloader.py -c client_id -s client_secret -i course_number -w module_number
If you do not specify module number, video from all the modules will be downloaded. Any video is downloaded in 720p by default. Please add -q and needed quality to the command to be able to download videos in 320 and 1080.
Working with ffmpeg
To use ffmpeg, please download and install it from https://ffmpeg.org/download.html. The program is launched via command prompt and can be used for changing the format and video compressing (see https://ffmpeg.org/ffmpeg.html#Description).
To merge several videos, use terminal to launch the following script from https://github.com/mehanig/common/blob/master/video_concater_and_compressor.sh
Compressing large videos
Use terminal to launch the following command ffmpeg -i INITIAL_VIDEO.mp4 -codec:a copy -vcodec libx264 -preset slow -crf 25 COMPRESSED_VIDEO.mp4