watermark

[vinnitu]

Hi All!

I want to add watermak (really other type of processing) on each frame end encode to same codec and container.

Is it possible with beamcoder? Maybe somebody have an example?

Thanks!

[jpietek]

Works exactly as in plain libav/ffmpeg:
https://ffmpeg.org/ffmpeg-all.html#overlay-1

[vinnitu]

yes... but if I want draw something on frame?

[Rock-N-Troll]

if you get each frame and change the pixel colors in the right spots and loop over and perform the action for all frames, you can do it (depending on colorspace. example below is for rgb pixels in a frame)

https://github.com/Streampunk/beamcoder#creating-frames
There can also be an alpha channel so just depends on the format (rgb, yuv, etc.). It will take some trial and error

pseudocode:

let frame = beamcoder.frame({
	      width: encParams.width,
	      height: encParams.height,
	      format: encParams.pix_fmt
	    }).alloc();// or whatever frame data you have, in a loop

	    let [ rgbdata ] = frame.data;//existing pixel values

	    rgbPixelCount = 3 * width* height; //3 values (r, g, and b) for every pixel of the frame from 0-255, so 0,1,2 are the 1st pixel rgb values

	    rgbdata[pixelToChange*3] = 0; //set r value
	    rgbdata[pixelToChange*3+1] = 0;//set g value
	    rgbdata[pixelToChange*3+2] = 0;//set b value

additional resource with similar approach:
#19