Burn Frame Number

How to burn frame numbers in the video in FFMPEG

ffmpeg -i <input> \
-vf "drawtext=fontfile=Arial.ttf: text=%{n}: x=(w-tw)/2: y=h-(2*lh): \
fontsize=20: fontcolor=white: box=1: boxcolor=0x00000099" \
-c:v libx264 -b:v 5M \
-c:a aac -ac 2 -b:a 128k <output.mp4>

Please note that when you are using the -vf video filter option you need always to encode the video. In this example, the font size is in pixels so I would suggest using different -fontsize depending on the output resolution. For SD 20 should be fine, for HD, 50 and for UHD 100. The burning of the frame numbers always require re-encoding the video, that's why I am re-encoding the input file to output.mp4 using H264 encoding and 5Mbps for the video stream and 128Kbps and AAC for the audio stream.

How to burn frame numbers in the video, re-scale it and de-interlacing it in FFMPEG

ffmpeg -i <input> \
        -vf 'scale=1280x720, bwdif=0:-1:0, drawtext=fontfile=Arial.ttf: text=%{n}: x=(w-tw)/2: y=h-(2*lh): \
        fontsize=35: fontcolor=white: box=1: boxcolor=0x00000099' \
        -c:v libx264 -r 50 -b:v 5M \
        -c:a aac -ac 2 -b:a 128k <output.mp4>

The difference here is that we separate the scale (re-scaling) and bwdif (de-interlacing) from the drawtext filter function with commas.