Something maybe challenging here: I want to stream (via rtmp) a video with a fixed image and a countdown applied on it. I know I can create a slideshow with even audio background with ffmtp (http://trac.ffmpeg.org/wiki/Create%20a%20video%20slideshow%20from%20images) but I'm wondering if I can loop it AND apply an overlay with the countdown to a given date.
Any ideas?
You can use the drawtext filter to apply the countdown on top of the video. The filter syntax would be
-vf "drawtext=fontfile='C\:\\Windows\\fonts\\Arial.ttf':
fontcolor=yellow:fontsize=45:x=100:y=65:
text='%{eif\:trunc((5447324-t)/86400)\:d\:2} days
%{eif\:trunc(mod(((5447324-t)/3600),24))\:d\:2} hrs
%{eif\:trunc(mod(((5447324-t)/60),60))\:d\:2} m
%{eif\:trunc(mod(5447324-t\,60))\:d\:2} s'"
The number 5447324 is the countdown duration expressed in seconds. That's the only variable related to the countdown you need to change.
If the input is an image or image sequence, you would just add the loop option before it i.e. -loop 1 -i image.png or -loop 1 -i img%03d.png. If you have a video, there is a stream_loop option. but it's buggy. Then, you would ingest the movie via the movie filter rather than as a direct input. Unless your video is long, I'd recommend converting it to an image sequence.