Newest 'ffmpeg' Questions - Stack Overflow

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• Creating a sample mp3 with fade

  2 novembre 2011, par tombazza

  I need to know if it is possible to create a 30 second sample MP3 from a WAV file. The generated MP3 file must feature a fade at the start and end.

  Currently using ffmpeg, but can not find any documentation that would support being able to do such a thing.

  Could someone please provide me the name of software (CLI, *nix only) that could achieve this?

• How to compile ffmpeg on android with external library

  2 novembre 2011, par Curtis

  I would like to build ffmpeg using android ndk. The basic clean build is work fine for me. However, I would like to add librtmp,libfaac,libx264 into ffmpeg. Then I add --enable-libXXXXX in build file,but it fail to do so. So can anyone tell me how can I build those file for ffmpeg? Where and what file should I put into the ffmpeg file? Please give me a helping hand Thank you

• Start/Stop Ffmpeg video capture

  2 novembre 2011, par Dasas

  I'm currently using ffmpeg for recording video from a webcam source.

  At the moment i use java to call for ffmpeg to execute.

  The code is pretty straightforward

  ffmpeg -f dshow -i video="Dualpix HD720p for Notebooks" -s cif -r 20 -f flv TEST.FLV
  Runtime.getRuntime().exec("rundll32 SHELL32.DLL,ShellExec_RunDLL " + cmd);
  

  and it works fine.

  The only real issue occour when when i need to stop the recording process.

  I know that i can press q or even ctrl+c in the CMD but i need to stop the process without keyboard input.

  That would be pretty easy to achive by killing the process but in this case ffmpeg do not finalize the video leaving me with a corrupt, need to fix, output.

  Is there any way to trigger the finalizing process "remotely".

  Thx, D.

  *******EDIT**********

  Thx for the prompt answer, i think you're referring to

  Process.getOutputStream()

  As for this case i have tried with this code:

  public Process doCommand(String cmd) throws Exception {
  
      rt = Runtime.getRuntime();
      Process proc = rt.exec(cmd);
      recOS= proc.getOutputStream();
      regcIS= proc.getInputStream();
  
      return proc;
  
  }
  
     receOS.write(("q/n".getBytes()));
     recOS.flush();
  

  I'm still getting an error, to be more specific, java.io.ioexception The pipe is being closed ...

• FFMPEG - Drawtext or drawbox or overlay on single frame

  2 novembre 2011, par waxical

  I'm using the avfilters on FFMPEG to drawtext and drawbox. Two of the most poorly documented functions known to man.

  I'm struggling to work out how and if I can use this on a single frame. I.e. appear drawtext on frame 22.

  Current command:-

  ffmpeg -i /home/vtest/test.wmv -y -b 800000 -f flv -vcodec libx264 -vpre default -s 768x432 -g 250 -vf drawtext="fontfile=/home/Cyberbit.ttf:fontsize=24:text=testical:fontcolor=green:x=100:y=200" -qscale 8 -acodec libfaac -sn -vstats  /home/testout.flv
  

  Two elements mention here in the documentation are n and t - however I only seem to be able to use them in x and y. Not in text or even as other parameters.

  Any help or ffmpeg guidance would be gratefully received.

• Xuggler encoding images to video FPS issue

  1er novembre 2011, par Chris Robinson

  I've been experimenting with encoding a video from a series of images using CaptureScreenToFile.java as a basis. My output is to be an MP4 file. From 26 images, using the code as is (taking the images from a directory instead of from a screen capture obviously), the encoding video is ~11s. However, if I change the framerate variable to:

  frameRate = IRational.make(1, 24);
  

  which I believe should result in a video of 24FPS. It does not however, (no change from the original video in fact). I experimented with changing the timeStamp variable in encodeImage() method to:

  long timeStamp = (firstTimeStamp*1000)+(i*40);
  

  where 0 < i < 25 to see if that would help but it doesn't. Can anyone explain to me how to encode a directory of images to a video with a framerate that I can set?