Recherche avancée

Sur d’autres sites (8064)

• Create background sound for video with ffmpeg

  23 novembre 2020, par Neret

  I have a video file without sound and a stereo audio file. Video is several times longer than audio. I'd like to create a background sound which starts from 2 second silence, then trim silence of the audio at both ends and duplicate trimmed audio several times to the end of the video.

  


  

  


  I found how to trim audio :

  


  ffmpeg -y -i audio.wav -af silenceremove=start_periods=1:start_threshold=-75dB,areverse,silenceremove=start_periods=1:start_threshold=-75dB,areverse trimmed_audio.wav


  


  And how to create silence :

  


  ffmpeg -y -f lavfi -i anullsrc=channel_layout=stereo:sample_rate=48000:duration=2 silence.wav


  


  How can I duplicate the audio and combine it with the video ?

  


• writing simple linux bash program to trim video using ffmpeg [closed]

  12 août 2020, par feri ariyatmoko
  


  1. I know I can trim video using ffmpeg without re-encoding it using this following command :ffmpeg -i 'inputvideo.mp4' -vcodec copy -acodec copy -ss 00:09:33 -to 00:11:53 'output.mp4'

     


  


  2. I've tried that command, it worked like a charm.

     


  


  3. Since I will trim a lot of videos, I think it's better if I have a simple bash program to do it.

     


  


  


  This is what the program should do :

  


  

  1. I use ubuntu, so the program should be written for linux system

  


  2. I execute the program : ./videotrimmer.sh inputvideo.mp4 outputvideo.mp4

  


  3. The program asks the starting time and the time it ends.

  


  4. I enter the times.

  


  5. And done !

  


  


  Example :

  


  

  1. I want to trim the first 3 secs of a 10 secs video named videofile10secs.mp4. The file name of the trimmed video is videofile3secs.mp4

  


  2. ./videotrimmer.sh videofile10secs.mp4 videofile3secs.mp4

  


  3. The program asks the times. I input "00:00:00" and "00:00:03"

  


  4. I press the return key.

  


  5. Done. I should have a new file videofile3secs.mp4.

  


  


  How to write that ? Any help will be highly appreciated.

  


• intreadwrite : Add intermediate variables in the byteswise AV_W*() macros

  1er août 2016, par Martin Storsjö

  intreadwrite : Add intermediate variables in the byteswise AV_W*() macros
  This avoids issues with expanding the argument multiple times,
  
  and makes sure that it is of the right type for the following shifts.
  Even if the caller of a macro could be expected not to pass parameters
  
  that have side effects if expanded multiple times, these fallback
  
  codepaths are rarely, if ever, tested, so it is expected that such
  
  issues can arise.
  Thefore, for safety, make sure the fallback codepaths only expand
  
  the arguments once.
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DBH] libavutil/intreadwrite.h