I'm at a loss at the moment. I have been testing and posting questions @ SO, VideoHelp, Doom9 -- nobody seems to have an answer. Maybe I have better luck here.
I'm trying to generate a transparent movie with ASS subtitles burnt in. The only way to do this correctly seems to be using AviSynth as an intermediate, but I'm sure there is another way. I can use colorkey, like below - and it'll create a usable transparent movie - but the edges of the subtitles are not smooth anymore: ffmpeg.exe -y -f lavfi -i color=s=1920x1080:color=0xff0000 -an -vf "ass=test.ass,colorkey=0xff0000:0.5:0.5,format=yuva420p" -c:v png -t "00:01:40.544" -threads 0 "video.mov" -stats It's clear that this is not the way to go. So my second way of thinking was creating a virtual background using lavfi, and setting this to a transparent color -- but I have not found a way to set a color and make it transparent using ffmpeg filters. Third try was to create a transparent png, loop it and overlay the subtitles: ffmpeg.exe -y -loop 1 -i transparent-1920x1080.png -vf "ass=test-normal.ass,format=rgba" -c:v png -t "00:00:10.000" -threads 4 "video-transparent.mov" -stats While I preview the resulting movie in a media player, it shows the subtitles on a white background, but when I import in Premiere or After Effects, the full movie is transparent. Like if the alpha channel is applied on top of the subtitles. Is there a way to get this done properly in ffmpeg? ᐧ _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
