Mirror webcam image

OPENRNDR Beginners
1

I’m getting video from a regular webcam like this:

    program {
        val videoPlayer = VideoPlayerFFMPEG.fromDevice()
        videoPlayer.play()
    }
     extend {
        videoPlayer.draw(drawer, 0.0, 0.0, 320.0, 240.0)
   }

I would like to flip the image horizontally. I see for Kinect cameras there’s a built in mirror property
kinect.depthCamera.mirror = true

Is there something similar for VideoPlayerFFMPEG or how would you approach it?

Thanks

1 Like
2

Maybe not the most optimal way, but it should work:

fun main() = application {
  program {
    val videoPlayer = VideoPlayerFFMPEG.fromDevice()
    videoPlayer.play()
    val renderTarget = renderTarget(width, height) {
      colorBuffer()
    }
    extend {
      drawer.withTarget(renderTarget) {
        videoPlayer.draw(drawer)
      }
      drawer.isolated {
        scale(-1.0, 1.0)
        translate(-width.toDouble(), 0.0)
        image(renderTarget.colorBuffer(0))
      }
    }
  }
}
1 Like
3

Worked like a charm. Thanks!

4

You can also draw it with negative width:

import org.openrndr.application
import org.openrndr.drawImage

fun main() = application {
    program {
        val cb = drawImage(400, 400) {
            circle(0.0, 0.0, 200.0)
        }
        extend {
            drawer.image(cb, cb.width.toDouble(), 0.0, -cb.width.toDouble(), cb.height.toDouble())
        }
    }
}

Or… maybe not with videoPlayer.draw? I’ll try…

Works too (The “:0” part works on Linux for screen grabbing):

import org.openrndr.application
import org.openrndr.ffmpeg.PlayMode
import org.openrndr.ffmpeg.VideoPlayerFFMPEG

fun main() = application {
    program {
        val videoPlayer = VideoPlayerFFMPEG.fromScreen(":0", PlayMode.VIDEO, 30.0, 640, 480)
        videoPlayer.play()
        extend {
            videoPlayer.draw(drawer, videoPlayer.width.toDouble(), 0.0, -videoPlayer.width.toDouble(), videoPlayer.height.toDouble())
        }
    }
}

Basically, draw the image where the top right corner should be and use it’s negative width as the width value. Like flipping left the right page of a book.

3 Likes