Recherche avancée

Sur d’autres sites (5514)

• Video files conversion/transcoding Google App Engine

  15 août 2013, par Vasilis

  I want to start a cloud computing project with the simple task to :

  1. Receive uploaded video files
  2. Do some transcoding / converting to them
  3. Allow user to download / stream the generated file

  I was thinking ffmpeg as an external command line tool integrated in a Java/Google App engine Application. Since it was fairly hard to be assured about the limitations of the framework, can someone tell me if this is feasible ?

  Thank you in advance !

• FFmpeg - Take 128 Channel WAV and Transcode to MKV with 128 Discrete Mono Tracks [closed]

  17 août 2023, par Matt Cohen

  I have a use case where I need to take individual WAV files with 128 channels in each one and output corresponding MKVs with each source channel as its own discrete mono track.

  


  I've been playing around with the channelsplit and channelmap functions but am having a hard time finding parameters that work with this many channels / this specific use case.

  


  Is this even possible with FFmpeg ?

  


  So far I've mostly been trying different variations of :

  


  ffmpeg -i in.wav -filter_complex channelsplit out.mkv

  


  Any help would be greatly appreciated.

  


• How can i convert and compress in real time batch of images to mp4 video file ?

  29 juin 2015, par Brubaker Haim

  In my directory on the hard disk i have many images : screenshot000001.bmp , screenshot000002.bmp....screenshot001200.bmp

  I want to do two things :

  1. For testing using the cmd(Command Prompt) and to compress and convert the images to mp4 video file.

  2. In my program in real time while my program take the screenshots and save them to the hard disk to compress them and build the mp4 video file in real time.

  For the first part i tried to type in cmd :

  ffmpeg -f image2 -i screenshot%d.bmp -vcodec libx264 -b 800k video.avi

  But what i got is two errors :

  [image2 @ 0000000004766380] Could find no file with path ’screenshot%d.bmp’ and
  index in the range 0-4
  screenshot%d.bmp : No such file or directory

  I copied the ffmpeg.exe to the directory where the images are in.
  E :\screenshots

  For the second part this how i’m taking the screenshots in real time :

  A button click event that start a timer :

  private void button1_Click(object sender, EventArgs e)
  
          {
  
              timer1.Start();
  
          }

  Then in the tick event :

      ScreenShot shot = new ScreenShot();
  
      public static int counter = 0;
  
      private void timer1_Tick(object sender, EventArgs e)
  
      {
  
          counter++;
  
          shot.GetScreenShot(@"e:\screenshots\", "screenshot");
  
          if (counter == 1200)
  
          {
  
              timer1.Stop();
  
          }
  
      }

  This line shot.GetScreenShot(@"e :\screenshots\", "screenshot") ; save the screenshots to the hard disk.
  Here after each screenshot save i want to compress and build the mp4 video file in real time.

  I tried this and got errors :

  ffmpeg -f image2 -i screenshot%06d.bmp -vcodec libx264 -b 800k video.avi

  Error message :

  ffmpeg version N-73165-gf1e1730 Copyright (
  
    built with gcc 4.9.2 (GCC)
  
    configuration: --enable-gpl --enable-vers
  
  isynth --enable-bzlib --enable-fontconfig -
  
  le-iconv --enable-libass --enable-libbluray
  
  enable-libdcadec --enable-libfreetype --ena
  
  ibilbc --enable-libmodplug --enable-libmp3l
  
  le-libopencore-amrwb --enable-libopenjpeg -
  
  able-libschroedinger --enable-libsoxr --ena
  
  ble-libtwolame --enable-libvidstab --enable
  
   --enable-libvorbis --enable-libvpx --enabl
  
  e-libx264 --enable-libx265 --enable-libxavs
  
  ble-decklink --enable-zlib
  
    libavutil      54. 27.100 / 54. 27.100
  
    libavcodec     56. 45.100 / 56. 45.100
  
    libavformat    56. 38.102 / 56. 38.102
  
    libavdevice    56.  4.100 / 56.  4.100
  
    libavfilter     5. 18.100 /  5. 18.100
  
    libswscale      3.  1.101 /  3.  1.101
  
    libswresample   1.  2.100 /  1.  2.100
  
    libpostproc    53.  3.100 / 53.  3.100
  
  [bmp @ 0000000002f77ce0] bad magic number
  
      Last message repeated 3 times
  
  [image2 @ 0000000002f76380] decoding for st
  
  [image2 @ 0000000002f76380] Could not find
  
   bmp, none): unspecified size
  
  Consider increasing the value for the 'anal
  
  screenshot%06d.bmp: could not find codec pa
  
  Input #0, image2, from 'screenshot%06d.bmp'
  
    Duration: 00:00:02.88, start: 0.000000, b
  
      Stream #0:0: Video: bmp, none, 25 fps,
  
  Please use -b:a or -b:v, -b is ambiguous
  
  Codec AVOption b (set bitrate (in bits/s))
  
  vi) has not been used for any stream. The m
  
  e (e.g. a video option with no video stream
  
  some encoder which was not actually used fo
  
  Output #0, avi, to 'video.avi':
  
  Output file #0 does not contain any stream