> From: JULIAN GARDNER <[email protected]> >To: [email protected] >Sent: Monday, 22 September 2014, 17:19 >Subject: [FFmpeg-user] Can work out why this does what it does > > >I am trying to do a little overlay test but cant work out why one works and >one fails, the input file i use is one of my SD stream captures from BBC News, >so a generic SD video will suffice > >The 2 command lines > >Working > > >ffmpeg -i <any input video file> -vcodec libx264 -preset ultrafast -b 3000k >-acodec libfaac -async 1 -r 25 -filter_complex 'color=s=640x360:c=#80808080 >[o1];[0:v] scale=640x360,drawbox=100:100:100:100:color=green [o0];[o0][o1] >overlay' -y -f mpegts a.ts > > >This give the desired result or an opaque screen overlayed over video > > >Non working one > >ffmpeg -i <any input video file> -vcodec libx264 -preset ultrafast -b 3000k >-acodec >libfaac -async 1 -r 25 -filter_complex >'color=s=640x360:c=#80808080,drawbox=100:100:100:100:color=red >[o1];[0:v] scale=640x360,drawbox=100:100:100:100:color=green >[o0];[o0][o1] overlay' -y -f mpegts a.ts > > >On this i get the color screen with no transparency and the red box > >Any ideas why adding a drawbox will make the color layer lose its transparency > >joolz
OK worked it out, drawbox does not work on any formats with ALPHA being present and coverts these down to non-alpha formats. Looks like im going to have to add in code for working with alpha planes joolz _______________________________________________ ffmpeg-user mailing list [email protected] http://ffmpeg.org/mailman/listinfo/ffmpeg-user
