I'm trying to fade a text in and out (the text has a background), at the moment, what I have is this command:
1. Blend command
ffmpeg -y -i input.mp4 -filter_complex "drawtext=fontfile=HelveticaNeue.ttf:text='Testing': fontcolor=white:fontsize=40: box=1: boxcolor=black@0.5:boxborderw=5:x=(w-text_w)/2:y=(h-text_h)/2[subtitles];[subtitles][0:v]blend=all_expr='A*(if(between(T,1,2),(T-1),0))+B*(1-(if(between(T,1,2),(T-1),0)))'[out]" -map '[out]' -map 0:a output.mp4
The command above successfully fades in the drawtext (aka subtitles in this filter), but I haven't managed to make it fade them out for some reason, because changing the numeric values of it don't quite have the result I expect.
I've also tried a command that is less complex but doesn't work too for other reasons:
2. Fade command
ffmpeg -y -i input.mp4 -filter_complex "drawtext=fontfile=HelveticaNeue.ttf:text='Testing': fontcolor=white:fontsize=40: box=1: boxcolor=black@0.5:boxborderw=5:x=(w-text_w)/2:y=(h-text_h)/2[subtitles]; [subtitles]fade=t=in:st=2:d=1,fade=t=out:st=3:d=1[out]" -map '[out]' -map 0:a output.mp4
This second command fades in and out, but applies to the entire video and not the subtitles part alone.
Any way someone can give me a hand with this?
The quick and dirty method to do this is to split the base video into two, draw the text on one copy, add an alpha channel, apply fades to the alpha, overlay the result onto the other copy.
e.g.
ffmpeg -y -i input.mp4 -filter_complex "[0]split[base][text];[text]drawtext=fontfile=HelveticaNeue.ttf:text='Testing': fontcolor=white:\
fontsize=40: box=1: boxcolor=black@0.5:boxborderw=5:x=(w-text_w)/2:y=(h-text_h)/2,format=yuva444p,fade=t=in:st=2:d=1:alpha=1,fade=t=out:st=3:d=1:alpha=1[subtitles]; \
[base][subtitles]overlay" output.mp4