video_stream.exs

Mix.install([evision: "~> 0.1"],
  system_env: [
    EVISION_PREFER_PRECOMPILED: "false",
    CMAKE_OPENCV_OPTIONS: "-D WITH_FFMPEG=ON"
  ]
)

alias Evision.VideoCapture

url = "rtsp://172.28.6.108:8554/mystream"

Stream.resource(
  fn -> VideoCapture.videoCapture(url, apiPreference: Evision.Constant.cv_CAP_FFMPEG()) end,
  fn
    %{isOpened: true} = video ->
      frame = if VideoCapture.grab(video), do: VideoCapture.retrieve(video)

      {[frame], video}

    %{isOpened: false} = video ->
      {:halt, video}
  end,
  fn video -> VideoCapture.release(video) end
)
|> Stream.each(&IO.inspect/1)
|> Stream.run()