ffmpeg libav bindings for crystal lang

Primarily to extract video frames from streams and files for processing by AI.

Installation

1. Add the dependency to your shard.yml:

   dependencies:
     ffmpeg:
       github: spider-gazelle/ffmpeg
   

2. Run shards install

3. ensure the required libraries are installed

   • sudo apt install libswscale-dev
   • sudo apt install libav-tools or sudo apt install ffmpeg

Usage

parsing a video file, outputs StumpyCore Canvas

require "ffmpeg"

video = Video::File.new("./test.mp4")
video.each_frame do |frame|
  puts "key frame? #{frame.key_frame?}"
  frame           # => FFmpeg::Frame
  frame.to_canvas # => StumpyCore::Canvas
end

also supports UDP streams (unicast or multicast)

require "ffmpeg"

video = Video::UDP.new("udp://239.0.0.2:1234")
video.each_frame do |frame|
  frame           # => FFmpeg::Frame
  frame.to_canvas # => StumpyCore::Canvas
end

You can also scale the frames

require "ffmpeg"

video = Video::File.new("./test.mp4")

# the scaler context
scaler = uninitialized FFmpeg::SWScale

# scaled frame we'll use for storing the scaling output
scaled_frame = uninitialized FFmpeg::Frame

video.on_codec do |codec|
  # scale by 50%
  width = codec.width // 2
  height = codec.height // 2
  scaler = FFmpeg::SWScale.new(codec, width, height, codec.pixel_format)
  scaled_frame = FFmpeg::Frame.new width, height, codec.pixel_format
end

video.each_frame do |frame|
  scaler.scale frame, scaled_frame

  # do something with the scaled frame
  scaled_frame.to_canvas
end

See the specs for more detailed usage

Contributing

1. Fork it (https://github.com/spider-gazelle/ffmpeg/fork)
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create a new Pull Request

Contributors

• Stephen von Takach - creator and maintainer