Newest 'ffmpeg' Questions - Stack Overflow

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• ffmpeg split into frames

  4 novembre 2011, par bradleyg

  Hey, I want to split a video which is one second long (25fps)into 25 seperate video files. I know I can split it up into jpegs but I need to retain the audio. So when I recompile audio is still there.

  This is what I tried to grab the first frame only (with audio):

  ffmpeg -i 1.mov -vcodec mjpeg -qscale 1 -an -ss 00:00:00:00 -t 00:00:00:1 frame1.mov
  

  But it doesn't seem to work. Am I wrong in assuming ffmpeg supports time stamps in this format? hh:mm:ss:f?

  Thanks

• Output a video to a file

  3 novembre 2011, par EagleEye

  I am working on a very CPU intensive legacy application on windows which captures video frames from camera and displays it on the screen. Now I need to add a feature to it to save this video feed to an output file. And I have a raw image data as an input. I need to make this process as efficient as possible so that it doesn't affect the performance of my application.

  So what are the best available API's in C++ that I can use to create an output video file. And moreover what should be the most efficient encoding format that I must use so that I get the maximum throughput. Also I may have to use some compression techniques. So what should be the best approach.

  Moreover can I use GPU acceleration for this process and how ?

  Uptil now I have encountered following tools that I may use :

  1. OpenCV
  2. Microsoft Media Foundation LIbrary or DirectShow
  3. ffmpeg

• 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 ...