ffmpeg drawtext to overlay text repeatedly over the whole video space

Question

I want a specific text like Hello world to be spread across multiple rows and over the whole video space/page like this.

I'm running ffmpeg commands in the python script using bash as a subprocess. Sample code:

subprocess.run( [ "ffmpeg", "-i", input_file, "-vf", f"drawtext=font={font_family}:text={watermark_text}:fontcolor={font_color}:fontsize={font_size}{background_box}:{watermark_position}", "-codec:a", "copy", "-preset", encoding_preset, f"./watermark/{media_id}.mp4", ] )

Is there any good way to achieve this?

Answer 1

This is your basic template. I assume the input is 720p.

ffmpeg -i 720p_input -f lavfi -i "color=black@0:s=64x64,format=yuva420p" -filter_complex "[1]trim=end_frame=1,drawtext=font={font_family}:text={watermark_text}:fontcolor={font_color}:fontsize={font_size}{background_box}:{watermark_position},rotate=a={degree}*PI/180:ow=hypot(iw,ih):oh=ow:c=black@0,loop=-1:1:0,tile=15x9,trim=end_frame=1[wm];[0][wm]overlay=0:0" -c:a copy -preset encoding_preset ./watermark/{media_id}.mp4

{degree} should be replaced by rotation angle. The ultimate size of each text cell is 64 x sqrt(2) = 90 pixels on each side. 15x9 is the tiling layout. Adjust this to cover the full input frame.