Broadcasting with FFMPEG #

Render a Clock as a Test Signal #

.\ffmpeg.exe -re -f lavfi -i color=color=black:size=1280x720:r=30 `
  -f lavfi -i anullsrc=channel_layout=stereo:sample_rate=44100 `
  -vf 'drawtext=fontfile=/Windows/fonts/ARIALNB.TTF:fontsize=128:fontcolor=white:text="%{localtime}":x=(w-text_w)/2:y=(h-text_h)/2' `
  -codec:v libx264 -s:v 1920x1080 -codec:a aac -b:a 128k -f flv `
  rtmps://live.cloudflare.com:443/live/RTMPS_STREAM_KEY_HERE

If you get a fontconfig “file not found” error, confirm the fontfile path exists.

Render a Timestamp as a Test Signal #

Relatedly, instead of a server-time clock, use an HH:MM:SS.mmm timestamp clock:

ffmpeg -re -f lavfi -i color=color=black:size=1280x720:r=30 -f lavfi \
  -i anullsrc=channel_layout=stereo:sample_rate=44100 \
  -vf "drawtext=fontsize=128:fontcolor=white:text='%{pts\:hms}':x=(w-text_w)/2:y=(h-text_h)/2" \
  -codec:v libx264 -bf 0 -s:v 1920x1080 -codec:a aac -b:a 128k -f flv \
  rtmps://live.cloudflare.com:443/live/RTMPS_STREAM_KEY_HERE