Recherche avancée

Sur d’autres sites (13318)

• How do I run the qt ffmpeg wrapper example ? (error : cannot find -lavutil)

  29 août 2013, par James

  I am using QT 4.8 on the raspberry pi trying to save a binary stream to a video file like mp4. I was able to create and save static images by converting it into a QImage, but QT does not seem to support actually saving that stream (or the series of QImages) to a video file.

  The only option I may have found is qt ffmpeg Wrapper
  https://code.google.com/p/qtffmpegwrapper/

  but the example won't run out of the box. I am having the same exact problem as this guy :

  https://code.google.com/p/qtffmpegwrapper/issues/detail?id=14&colspec=ID%20Type%20Status%20Priority%20Milestone%20Owner%20Summary%20Opened%20Closed%20Modified#makechanges

  All I did was download it and try to run the included example, but no go.
  Am I supposed to download ffmpeg files prior to using this ? apt-get install ffmpeg ?

  Thanks !

• Remove watermark by merging two videos

  29 septembre 2019, par LoStack

  I have actually two videos, one in high quality but with watermark and the other in poor quality without watermark. They are not synchronized.

  I would like to do something like the removelogo filter of ffmpeg but instead to simply interpolate like removelogo I would like to extract a part of a frame of the poor quality video to put it on the highest quality video with a mask to hide the watermark.

  Unfortunately the two videos are not synchronized and I would like to synchronize with the audio stream.

  Is it possible to do that with ffmpeg ?
  Thank you very much.

• Mix original clip audio with audio of an overlay clip

  28 octobre 2019, par Mr. Messy

  I have a video clip on which I want to add commentary videos (someone talking in a bubble).
  I have 3 commentary videos I need to insert in specific times.

  The video rendering is working well, but I can’t seem to add the audio tracks.
  I tried both amix and amerge, but I got the same issue.

  When I added "[0:1][2:1]amerge ;" I get the follwing :

  

  and the process freezes.

  The full ffmpeg command is as follows :

  ffmpeg -y   -i story.mp4
  
          -loop 1 -i mask.png
  
          -itsoffset 10 -i commentary1.mp4
  
          -itsoffset 22 -i commentary2.mp4
  
          -itsoffset 34 -i commentary3.mp4
  
          -filter_complex "[0:v]scale=w=1/2*in_w:h=1/2*in_h[vid1],
  
                          [2:v]crop=w=480:h=480:x=0:y=120[vid2in],
  
                              [1:v]fifo[2af],[2af]alphaextract[alf2],[vid2in][alf2]alphamerge[vid2alf],
  
                              [vid2alf]format=yuva420p,fade=in:st=10:d=0.5:alpha=1,fade=out:st=22.7294:d=0.5:alpha=1[vid2fade],
  
                              [vid2fade]scale=w=-1:h=160[vid2],
  
                              [vid1][vid2]overlay=790:10:enable='between(t\,10,21)'[out2],
  
                          [3:v]crop=w=480:h=480:x=0:y=120[vid3in],
  
                              [1:v]fifo[3af],[3af]alphaextract[alf3],[vid3in][alf3]alphamerge[vid3alf],
  
                              [vid3alf]format=yuva420p,fade=in:st=22:d=0.5:alpha=1,fade=out:st=32.768733:d=0.5:alpha=1[vid3fade],
  
                              [vid3fade]scale=w=-1:h=160[vid3],
  
                              [out2][vid3]overlay=790:10:enable='between(t\,22,33)'[out3],
  
                          [4:v]crop=w=480:h=480:x=0:y=120[vid4in],
  
                              [1:v]fifo[4af],[4af]alphaextract[alf4],[vid4in][alf4]alphamerge[vid4alf],
  
                              [vid4alf]format=yuva420p,fade=in:st=34:d=0.5:alpha=1,fade=out:st=44.598189:d=0.5:alpha=1[vid4fade],
  
                              [vid4fade]scale=w=-1:h=160[vid4],
  
                              [out3][vid4]overlay=790:10:enable='between(t\,34,45)'[out4]"
  
          -map [out4] -pix_fmt yuv420p -c:v libx264 -crf 18
  
          final_video.mp4

  (mask.png is a circle on a transparent image that crops the video to a bubble)

  Thank you for your help.