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• ffmpeg : drawtext fade in/out with zmq

  11 novembre 2019, par jb_alvarado

  There are several ways to fade in and out text in ffmpeg. But I only found solutions where the actual time is known.

  But what can I do, when I don’t know the current running time and I would like to fade in and out a text ?

  Let’s say I have an endless stream and I want to fade in a text with zmqsend. And the fade should start immediately. For that my understanding is, that I need to store some time information in a variable and calculate with that. But storing variables is not possible in ffmpeg expressions - right ?

  For testing purposes here are a playing instance :

  ffplay -dumpgraph 1 -f lavfi "color=s=512x288:c=black,zmq,drawtext=text=''"

  For adding some text with zmq I can run now :

  echo Parsed_drawtext_2 reinit text="Hello\ World,\ what’s\ up?" | zmqsend

  Or if I know the running time and after 10 seconds I want the text fade in :

  "text='Hello\ World':fontsize=:fontcolor=ffffff:alpha='if(lt(t,10),0,if(lt(t,11),(t-10)/1,if(lt(t,16),1,if(lt(t,17),(1-(t-16))/1,0))))'"

  My goal is now to have an expression what I can send, so that ffmpeg starts fading in the text and out after a certain time.

  Something like :

  now=t,if(lt(t,now+10),0,if(lt(t,now+11),(t-(now+10))/1,if(lt(t,now+16),1,if(lt(t,now+17),(1-(t-(now+16)))/1,0))))

  Is there a way to store variables in expression, or is there any other way to realize this ?

• A "region code" restriction for a custom created video dvd file [closed]

  17 décembre 2012, par user931392

  I want to create a video dvd ( no menus, just "plug and play" ) from a few video files. I`m doing it like this :

  ffmpeg -i sample-media/hellboy-2.wmv -y -target ntsc-dvd sample-media-to-mpeg/hellboy-2.vob
  
  
  
  dvdauthor -o sample-dvd -x dvdauthor-settings.xml
  
  
  
  mkisofs -dvd-video -o hellboy-2-trailers.iso sample-dvd/

  where "dvdauthor-settings.xml" is : link.

  But when I try to play the iso file in windows it says :

  Windows Media Player cannot play the DVD because the disc prohibits playback in your region of the world. You must obtain a disc that is intended for your geographic region.

  When I open the *.IFO file with IfoEdit it says that all world regions are unabled.

  Can someone tell me why is this happening ? ( maybe the whole process of creating the *.iso file is wrong ? )

• mpeg-dash toolkit, how can I make such videos ?

  21 mai 2015, par sathia

  I was reading about this nice specification but I’m not sure what’s the current status. Ffmpeg has some coverage

  http://ffmpeg.org/ffmpeg-all.html#webm_005fdash_005fmanifest

  but it is not clear to me if I could encode videos in such format.
  So, the question is, If I were to produce mpeg-dash compliant videos, how would I do nowadays ? thanks !