video-generator

This is tested in macOS Mojave 10.14.6 (18G87)

Installation

Please make sure you install FFMPEG library in your machine before using this gem.

    gem install erika   

Requirements

FFMPEG

A complete, cross-platform solution to record, convert and stream audio and video.

MacOSx

brew install ffmpeg

Ubuntu

apt-get install ffmpeg

Usage

To compile images in ~/pictures/birthday, you need to make sure files are named in proper order. I recommend you to prefix the files with number like

- 0 My first birthday.jpg
- 1 My second birthday.jpg
- 2 My second birthday.jpg
- 3 My third birthday.jpg

single command to compile

cd ~/pictures

erika g -s birthday -o mybirthday.mp4 

# This will generate video called `mybirthday.mp4`

Options

 erika help g
Usage:
  erika g

Options:
  -o, [--output=OUTPUT]                            # Output path; where to generate output movie
  -s, [--source=SOURCE]                            # Input path; folder path where the images are located
  -a, [--audio=AUDIO]                              # Audio path; the path to bg audio
  -t, [--transition-duration=TRANSITION_DURATION]  # Transition animation duration between two images
  -S, [--slide-duration=SLIDE_DURATION]            # Slide duration between two images

Generate movie

Example:-

 erika g -s happy -S=5 -t=4 -o=opt/mymovie.mp4

How Slide Animation is implemented

Creating intermediate mpeg's for each image and then concatenate them all into a video.

For example, say you have 5 images; you would run this for each one of the images to create the intermediate mpeg's with a fade in at the beginning and a fade out at the end.

ffmpeg -y -loop 1 -i <your-image> -vf "fade=t=in:st=0:d=0.5,fade=t=out:st=4.5:d=0.5" -c:v mpeg2video -t 5 -q:v 1 image-1.mpeg

where t is the duration, or time, of each image. Once you have all of these mpeg's, you use ffmpeg's concat command to combine them all into an mp4.

ffmpeg -y -i image-1.mpeg -i image-2.mpeg -i image-3.mpeg -i image-4.mpeg -i image-5.mpeg -filter_complex '[0:v][1:v][2:v][3:v][4:v] concat=n=5:v=1 [v]' -map '[v]' -c:v libx264 -s 1280x720 -aspect 16:9 -q:v 1 -pix_fmt yuv420p output.mp4

Components Used

• get Image dimension

  • https://stackoverflow.com/a/32824749/3437900
  • https://askubuntu.com/a/577431

• IMAGE SCALING

  • https://www.bogotobogo.com/FFMpeg/ffmpeg_image_scaling_jpeg.php

• FFMPEG filters

  • https://ffmpeg.org/ffmpeg-filters.html#subtitles-1

• Resizing and padding image

  • https://superuser.com/a/991412

• Capturing STD Streams to prevent logs being cluttered

  • https://ruby-doc.org/stdlib-1.9.3/libdoc/open3/rdoc/Open3.html#method-c-capture3

• Animation in Slide Transition

  • https://stackoverflow.com/questions/30974848/animation-between-images-using-ffmpeg
  • https://superuser.com/questions/833232/create-video-with-5-images-with-fadein-out-effect-in-ffmpeg/834035#834035

• Image to Video Guide FFMPEG

  • https://en.wikibooks.org/wiki/FFMPEG_An_Intermediate_Guide/image_sequence

• Repeat Audio and generate a new audio file

  • https://stackoverflow.com/a/8017021/3437900

• Add Subtitles to the video

  • https://trac.ffmpeg.org/wiki/HowToBurnSubtitlesIntoVideo

  https://superuser.com/questions/547296/resizing-videos-with-ffmpeg-avconv-to-fit-into-static-sized-player/1136305#1136305 https://trac.ffmpeg.org/wiki/Concatenate